فهرست مطالب

مطالعات حفاظت گیاهان - سال سی و یکم شماره 2 (تابستان 1396)
  • سال سی و یکم شماره 2 (تابستان 1396)
  • تاریخ انتشار: 1396/06/20
  • تعداد عناوین: 18
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  • علمی - پژوهشی
  • سعیدالسادات فاطمی، محمد امین سمیع صفحات 179-190
    شته سبز انار، Aphis punicae Pass. عمومی ترین آفت درختان انار محسوب می گردد که در تمامی انارستان های کشور وجود دارد و در بعضی از سال ها، در باغ هایی که شرایط برای رشد و تکثیر آفت فراهم باشد باعث خسارت می گردد. در این پژوهش، واکنش تابعی کفشدوزک شکارگر Menochilus sexmaculatus نسبت به تراکم های مختلف پوره های سن سه و چهار شته سبز انار به عنوان طعمه در دماهای 20، 5/22، 25، 5/27، و 30 (1±) برای ماده های بالغ 10 روزه و 25 و 5/27 (1±) درجه سلسیوس برای لاروهای سن سه و چهار و رطوبت نسبی 5±65 درصد و دوره نوری 16 ساعت روشنایی و 8 ساعت تاریکی بررسی شد. تراکم های استفاده شده برای لارو سن سه و چهار کفشدوزک شامل 2، 4، 8، 16، 32، 64، 100 و 128 طعمه و برای ماده بالغ و حشرات کامل نر و ماده 10 روزه شامل 8، 16، 32، 64، 100 و 128 طعمه بود و میزان تغذیه در هر تراکم پس از 24 ساعت ثبت شد. نوع واکنش تابعی به وسیله رگرسیون لجستیک و تخمین فراسنجه از طریق رگرسیون غیر خطی تعیین شد. واکنش تابعی تمامی مراحل مختلف رشدی کفشدوزک در تمام دماها از نوع دوم بود. نتایج نشان داد که دما در واکنش شکارگر به تراکم طعمه موثر بود و قدرت جستجوگری از دمای 5/22 تا دمای 5/27 افزایش یافت. بیش ترین و کمترین مقدار قدرت جستجوگری به ترتیب 14/0 و 05/0 بار در ساعت توسط حشرات بالغ ماده در دمای به ترتیب 5/27 و 5/22 درجه سلسیوس و برای زمان دستیابی به ترتیب 26/0 و 018/0 ساعت در دمای به ترتیب 20 و 5/22 درجه سلسیوس به دست آمد. بنابراین با نگرش به قدرت جستجوگری، دمای 5/27 درجه سلسیوس مناسب ترین دما برای فعالیت شکارگری این کفشدوزک در طبیعت در نظر گرفته می شود و مرحله رشدی حشرات کامل و لارو سن چهار بهترین مرحله است و در برنامه مهار زیستی شته سبز انار با این کفشدوزک در خور نگرش است. نتایج این پژوهش نشان می دهد که کفشدوزک زیگزاگی شش لکه ای احتمالا می تواند گزینه مناسبی برای مهار زیستی شته سبز انار در برنامه مدیریت تلفیقی آفات باغ های انار باشد.
    کلیدواژگان: زمان دستیابی، قدرت جستجوگری، شکارگر
  • سید حیدر موسوی انزابی صفحات 191-198
    کلزا (Brassica napus L.) یکی از گیاهان دانه روغنی مورد توجه کشاورزان در ایران می باشد. شته مومی کلم Brevicorynebrassicae (L.) از آفات مهم کلزا در استان آذربایجان غربی است. به منظور ارزیابی مقاومت چهار ژنوتیپ”RGS“ ، ”Hyola-308“ ،”Hyola-401“ و ”Sarigol“ نسبت به شته مومی کلم در سال 1389 مطالعه ای در دو بخش مزرعه و گلخانه در منطقه کهریز استان آذربایجان غربی انجام شد. در این تحقیق شاخص آلودگی و تحمل در شرایط مزرعه و آنتی بیوز در شرایط گلخانه مطالعه گردید. در بخش زراعی دو آزمایش جداگانه در قالب طرح بلوک های کامل تصادفی با پنج تکرار تحت شرایط آلودگی طبیعی وپنج تکرار کنترل (عدم آلودگی) در مزرعه کاشته شد. در مزرعه از شاخص آلودگی زراعی و شاخص کاهش تابعی عملکرد در بررسی مکانیسم های مقاومت ژنوتیپ ها استفاده شد. در ارزیابی آنتی بیوز، ژنوتیپ ها در گلدان هایی در 10 تکرار و بر اساس طرح کاملا تصادفی کاشته شدند و نرخ ذاتی رشد جمعیت شته مومی کلم در شرایط گلخانه ای محاسبه گردید. نتایج تجزیه واریانس مرکب شاخص آلودگی اختلاف آماری معنی داری حداقل در سطح احتمال یک درصد برای صفت شاخص آلودگی در بین ژنوتیپ ها و زمان های نمونه برداری نشان داد. تجزیه شاخص کاهش عملکرد و اجزای آن بر پایه بلوک های کامل تصادفی، اختلاف آماری معنی داری حداقل در سطح احتمال یک درصد برای این صفات نشان داد. تجزیه واریانس ساده داده های آزمایش گلخانه ای آنتی بیوز اختلاف آماری معنی داری در سطح احتمال یک درصد برای صفت نرخ ذاتی افزایش جمعیت شته را نشان داد. در نهایت ژنوتیپ ”Sarigol“ بیش ترین شاخص مقاومت گیاهی را در مقایسه با دیگر ژنوتیپ ها دارا بود.
    کلیدواژگان: آذربایجان غربی، آنتی بیوز، تحمل، شاخص آلودگی، شاخص مقاومت گیاهی
  • ابراهیم مهاجری، ناصر پنجه که، مرتضی قربانی، نبی خضری نژاد صفحات 199-212
    با هدف شناسایی فون نماتدهای انگل گیاهی تاکستان های جنوب آذربایجان غربی طی سال های 92 و 93 تعداد 50 نمونه خاک ریزوسفر ریشه انگور از پنج شهر مهاباد، بوکان، سردشت، پیرانشهر و میاندوآب جمع آوری شد. نماتدها جداسازی، تثبیت و به گلیسیرین خالص رسانده شدند و اسلایدهای تهیه شده از نمونه ها به وسیله میکروسکوپ نوری مجهز به لوله ترسیم، از نظر صفات ریخت شناسی و ریخت سنجی مورد بررسی قرار گرفتند. شناسایی جنس ها و گونه ها با استفاده ازمنابع و کلیدهای معتبر انجام و شباهت ها و تفاوت های موجود بین افراد با شرح اصلی گونه و گونه های نزدیک مورد بحث قرار گرفت. در نهایت 23 گونه متعلق به 15 جنس شامل Amplimerlinius globigerus،Basiria tumida،Boleodorus thylactus ،Discotylenchus discretus ،Ditylenchus acutus ،Ditylenchus myceliophagus ، Filenchus vulgaris ،Geocenamus brevidens ،Geocenamus rugosus،Helicotylenchus pseudorobustus ،Helicotylenchus vulgaris ،Mesocriconema antipolitanum ،Mesocriconema xenoplax ، Paratylenchus labiosus ،Pratylenchoides variabilis،Pratylenchus coffeae ، Pratylenchus neglectus،Pratylenchus penetrans ،Pratylenchus sefaensis ،Praylenchus scribneri ، Scutylenchus paniculoides ،Xiphinema index وZygotylenchus guevarai شناسایی شدند. پنج گونه Helicotylenchus vulgaris، Mesocriconema antipolitanum، Mesocriconema xenoplax، Helicotylenchus pseudorobustus و Pratylenchus neglectus به ترتیب و بر حسب میزان پراکنش و تعداد نمونه های خاک جداسازی شده به عنوان گونه های انگل غالب و نه گونه Discotylenchus discretus، Ditylenchus acutus،Paratylenchus labiosusPratylenchoides variabilis،Pratylenchus coffeae، Pratylenchus penetrans، Pratylenchus scribneri، Pratylenchus sefaensis و Scutylenchus paniculoides برای نخستین بار از خاک اطراف ریشه انگور در ایران گزارش می شوند. با توجه به گزارش های قبلی از این نماتدها در ایران، تنها به توصیف گونه های انگل غالب پرداخته می شود.
    کلیدواژگان: انگور، ریخت شناسی، ریزوسفر
  • محمدحسن رنجبر، جاوید قرخلو، افشین سلطانی صفحات 213-222
    عملیات خاک‏ورزی، شرایط بهینه رشد و نمو را برای گیاهان زراعی فراهم می کند. خاک‏ورزی حفاظتی در مقایسه با خاک‏ورزی متداول دارای مزایای بسیاری از لحاظ بهبود شرایط خاک و حفظ رطوبت خاک‏ می‏باشد. با وجود این در هنگام آماده‏سازی بستر کشت، کاهش برهم زدن خاک در روش‏های مختلف خاک‏ورزی حفاظتی می‏تواند باعث ایجاد شرایط بهینه برای رشد علف‏های هرز مختلف شوند. به منظور بررسی اثر نظام‏های خاک‏ورزی متداول، کم‏خاک‏ورزی و بدون خاک‏ورزی بر روی یکنواختی و تنوع علف‏های هرز موجود، در ابتدا و انتهای دوره بحرانی کنترل علف های هرز ذرت علوفه‏ای، در سال 1392 در شهرستان آزادشهر در قالب طرح نستد این آزمایش انجام شد که هر تیمار در یک پلات با سطحی معادل 1500 متر مربع اعمال شد. با استفاده از یک کادر یک در یک متر مربع، از هر کرت تعداد 15 نمونه برداشته شده و در هر کادر تراکم علف های هرز به تفکیک گونه شمارش شد. شاخص تنوع سیمپسون در ابتدای دوره بحرانی برای نظام بدون خاک‏ورزی معادل 30/0 وکمتر از دو نظام دیگر بود. این در حالی بود که در انتهای دوره بحرانی مقدار این شاخص در نظام خاک‏ورزی متداول به میزان 40/0 بوده که کم تر از نظام کم‏خاک‏ورزی و بدون خاک‏ورزی به دست آمد. شاخص یکنواختی کامارگو در ابتدا و انتهای دوره بحرانی کنترل علف های هرز برای نظام بدون خاک‏ورزی به ترتیب معادل 16/0 و 24/0 بود. این در حالی بود که در ابتدا و انتهای دوره بحرانی کنترل علف های هرز مقدار این شاخص در نظام خاک‏ورزی متداول به میزان 16/0 و 19/0 و کم خاک ورزی در هر دو مرحله به میزان 20/0 به دست آمد.
    کلیدواژگان: شاخص سیمپسون، شاخص کامارگو، دوره بحرانی علف های هرز، سیستم های خاک ورزی
  • حسین حمامی، رضا قربانی، اکبر علی وردی صفحات 223-231
    امروزه یکی از مهمترین چالش های مدیریت شیمیایی علف های هرز انتخاب مویان مناسب برای علف کش های مورد استفاده است. برای تعیین بهبود کارآیی علف کش های سولفوسولفورون و متسولفورون متیل+ سولفوسولفورون در کنترل یولاف وحشی بوسیله ی افزودن دو نوع مویان شامل مویان کاتیونی فریگیت و مویان غیر یونی سیتوگیت، آزمایشی دز پاسخ گلدانی در محیط گلخانه و محیط باز انجام شد. سولفوسولفورون در 6 غلظت (20 و 15 ،10 ،5 ،5/2 ،0 گرم ماده موثره در هکتار) و مت سولوفرون متیل+ سولفوسولفورون در 6 غلظت (45 (187/42+813/2)، و 75/33 (641/31+109/2)، 5/22 (094/21+406/1)، 25/11 (546/10+703/0)، 625/5 (273/5+351/0) و 0 گرم ماده موثره در هکتار) به تنهایی و به همراه غلظت های %1/0 و 2/0 درصد حجمی مویان به کار برده شدند. هر دو نوع مویان در کاهش کشش سطحی محلول علف کش ها موثر بودند. مقادیر کشش سطحی در سولفوسولفورون برای تیمارهای بدون مویان، فریگیت %1/0 و %2/0 حجمی و سیتوگیت %1/0 و %2/0 حجمی به ترتیب کاهش 58/9، 92/33، 40/35، 73/47 و 60/59 درصدی را نسبت به آب شیر نشان داد. این مقادیر برای متسولفورون متیل+ سولفوسولفورون به ترتیب 03/11، 07/27، 50/29، 93/51 و 39/56 درصد نسبت به آب شیر کاهش نشان داد. بنابراین مویان غیریونی در کاهش کشش سطحی موثرتر از مویان کاتیونی بود. مقادیر دز موثر50% در سولفوسولفورون برای تیمارهای بدون مویان، سیتوگیت %1/0 و %2/0 و فریگیت %1/0 و %2/0 حجمی در گلخانه به ترتیب برابر 94/8، 60/4، 17/3، 98/2 و 74/2 و در محیط باز به ترتیب برابر 11/13، 81/7، 90/5، 66/5 و 65/3 گرم ماده موثره در هکتار می باشد. مقادیر دز موثر50% در متسولفورون متیل+ سولفوسولفورون برای تیمارهای بدون مویان، سیتوگیت %1/0 و %2/0 و فریگیت %1/0 و %2/0 حجمی در گلخانه به ترتیب برابر 13/13، 71/9، 01/7، 34/6 و 57/5 و در محیط باز به ترتیب برابر 86/27، 48/17، 27/13، 72/12 و 27/8 گرم ماده موثره در هکتار می باشد. با توجه به مقادیر دز موثر50%، کارآیی سولفوسولفورون از متسولفورون متیل+ سولفوسولفورون بیشتر بود. در این آزمایش کارآیی هر دو علف کش بر روی گیاهان رشد یافته در گلخانه در مقایسه با گیاهان محیط باز بیشتر بود. دز موثر هر دو علف کش وقتی در مخلوط با مویان ها بکار رفتند، کاهش یافت. مویان کاتیونی توانایی بیشتری در بهبود کارآیی علف کش های مورد آزمایش در هر دو آزمایش گلخانه ای و محیط باز داشت. نتایج این مطالعه این ایده را تایید و تقویت کرد که مویان های محلول در آب باید برای علف کش های محلول در آب استفاده شوند و بالعکس.
    کلیدواژگان: دز پاسخ، سولفوسولفورون، سیتوگیت، فریگیت، متسولفورون متیل+ سولفوسولفورون
  • مریم سادات علی زاده، مهدی اسفندیاری، محمد سعید مصدق، منصور مشایخی صفحات 232-241
    شپشک آردآلود صورتیMaconellicoccus hirsutus (Green) ، از جمله آفاتی است کهبه عنوان یک تهدید اقتصادی جدی برای محصولات کشاورزی در بسیاری از مناطق گرمسیری و نیمه گرمسیری محسوب می شود. در این تحقیقزیست شناسی آفتدر 4دمای20، 25، 30 و 2±35 درجه ی سلسیوس در آزمایشگاه(رطوبت نسبی 5±65 درصد و دوره نوری 10:14 ساعت (روشنایی: تاریکی)) و نیز درون قفس های برگیروی بوته های ختمی چینی بررسی و همچنین تغییرات انبوهی آن روی این میزبان گیاهی در فضای سبز شهری اهواز مطالعه شد.در این بررسی میانگین طول کل دوره ی رشدی شپشک ماده از تخم تا مرگ در دماهای بالا، به ترتیب 15/1±18/91، 84/0±68/51، 68/0±18/38 و 64/0±93/36 روز بود. همچنین این مقدار برای شپشک های نر در شرایط مذکور به ترتیب 57/1±69/60، 48/0±67/33، 58/0±33/24 و 62/0±37/21 روز محاسبه شد.در دمای 1±15 درجه ی سلسیوستخم ها تفریخ نشدند.طول کل دوره ی رشدی برای شپشک های ماده و نر در دمای 20 درجه ی سلسیوس بیشترین و در دمای 35 درجه ی سلسیوس کمترین بود.در دمای 30 درجه شپشک کوتاه ترین دوره زندگی و بیشترین باروری را داشت. بر اساس نتایج قفس های برگی، تعداد نسل های شپشک آردآلود صورتیدر اهوازحداکثرهفت نسل در سال تعیین شد. نتایج حاصل از بررسی انبوهی جمعیت نشان داد که نسل اول تا سوم که نسل های بهاره را تشکیل می دادند، دارای بیشترین جمعیت بودند. تلفیق اطلاعات حاضر با تحقیقات گذشته میتواند دورنمای مناسبی به محققین در خصوص تلاش برای کنترل این آفت در ایران ارائه دهد.
    کلیدواژگان: تغییرات جمعیت، تعداد نسل، فضای سبزشهری
  • حسین کربلایی خیاوی، محمد حاجیان شهری، کاووس کشاورز، حسین خباز جلفایی، اسفندیار ظهور، محمد بازوبندی صفحات 242-249
    این تحقیق با هدف بررسی تاثیر فرمولاسیون جدید قارچ کش سولفور SC 80% و پنکونازول EW 20% در کنترل بیماری سفیدک پودری انگور آزمایشی در استان های اردبیل، خراسان رضوی و کهگیلویه و بویراحمد بر روی رقم حساس انگور عسکری در قالب طرح بلوک های کامل تصادفی با پنج تیمار و چهار تکرار اجرا شد. تیمارهای آزمایش شامل قارچکش های پنکونازول EW 20% (125/0 در هزار)، سولفورSC 80% در سه غلظت (2، 5/2 و 3 در هزار) و شاهد بدون سم پاشی (آب-پاشی) بودند. سم پاشی در 3 نوبت، طول شاخه های نورسته بین 15 تا 35 سانتی متر، قبل از ریزش گل ها و در مرحله تشکیل غوره ها انجام شد. یک هفته بعد از آخرین سمپاشی نمونه برداری تصادفی از برگ ها و خوشه ها از چهار جهت اصلی تاج پوشش سه درخت مرکزی در هر پلات انجام شد. نتایج تجزیه واریانس مرکب صفات انگور نشان داد بین مکان ها از لحاظ صفات شدت بیماری در برگ ها و میوه ها، بین تیمارها و اثر متقابل مکان و تیمار از لحاظ صفات شدت بیماری در برگ ها و میوه ها و عملکرد خوشه اختلاف معنی داری وجود داشت. نتایج تجزیه واریانس صفات مقدار قند و غلظت اسید در حبه انگور در منطقه اردبیل (مشگین شهر) اختلاف معنی داری بین تیمارها نشان داد. براساس نتایج بدست آمده سولفور SC 80% با غلظت های 5/2 و 3 در هزار بیشترین تاثیر را در کاهش بیماری سفیدک پودری و افزایش عملکرد خوشه و کیفیت انگور داشت.
    کلیدواژگان: تاکستان، شدت بیماری، قند، کنترل، Erysiphe necator
  • عزیز شیخی گرجان، مجتبی محمدیزاده، محمدرضا نعمتیان، فریبرز زرانی صفحات 250-256
    موریانه ها یکی از مهمترین عوامل تهدید کننده عرصه های جنگل کاری می باشند. منطقه جنگل کاری شده شلمزار واقع در استان البرز با مساحتی در حدود 54 هکتار، ازجمله مناطقی بود که در سال 1394 تحت تاثیر خسارت موریانه قرار گرفت. این تحقیق به منظور ارزیابی مقاومت هشت گونه نهال کاشته شده در برابر خسارت موریانه در این منطقه و شناسایی گونه موریانه خسارت زا روی آن ها اجرا شد. نمونه برداری از اندام های آلوده نهال ها از چهار نقطه آلوده منطقه نشان داد که موریانه خسارت زا در این منطقه گونه Microcerotermes gabrielis می باشد. نتایج حاصل از بررسی میانگین درصد آلودگی به موریانه در هشت گونه جنگلی نشان داد که گونه های گیاهی عرعر و بادام کوهی هیچ گونه آلودگی به موریانه نداشتند (صفر درصد) و به عنوان مقاوم ترین گونه های گیاهی در منطقه شناخته شدند و گونه گیاهی بنه با 30 درصد آلودگی در رتبه بعدی قرار گرفت. همچنین گونه های سنجد و داغداغان به ترتیب با 65 و 5/57 درصد آلودگی، حساسترین گونه های گیاهی به موریانه بودند. درصد نهال های ازبین رفته در دو گونه اخیر 55 و 65 درصد نسبت به کل نهال های آلوده بود. در نهال های آلوده ارغوان تنها 20 درصد از بین رفته بودند و در گروه نهال متحمل به موریانه قرار گرفت. گونه های زبان گنجشک و زرشک با درصد آلودگی و خسارت کمتر از 50 درصد در گروه نسبتا حساس به موریانه قرار گرفت. بنابراین گونه های گیاهی عرعر و بادام کوهی را می توان جایگزین نهال های از بین رفته در منطقه کرد.
    کلیدواژگان: آلودگی، البرز، جنگل کاری، خسارت
  • احسان الله زیدعلی، روح الله مرادی، عبدالرضا احمدی، مجتبی حسینی صفحات 257-266
    به منظور شناخت ویژگی های اکولوژیک برخی خصوصیاتجوانه‏زنی و سبز شدن بذور کنگر ابلق که از گیاهان هرز خسارتزا در محصولات زمستانه به شمار می رود، آزمایشات جوانه زنی در قالب طرح کاملا تصادفی با چهار تکرار در سال 1392 در آزمایشگاه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد اجرا شد. اثر دما بر جوانه زنی بذور در ژرمیناتور تحت نوسان دمایی 5/15، 10/20، 15/25، 15/30و 20/35 درجه سانتی گراد شب/روز، اثر شوری با استفاده از محلول های صفر، 10، 20، 40، 80، 160 و 320 میلی مولار کلرور سدیم و اثر اسیدیته با استفاده از محلول های بافر با اسیدیته تنظیم شده 5 تا 9 به طور جداگانه مورد بررسی قرار گرفت. برای مطالعه ی اثر عمق دفن بذر روی سبزشدن گیاهچه، بذور گیاه در اعماق صفر، 1، 2، 4 و 8 سانتی متر دفن شدند. نتایج نشان داد بالاترین و پایین ترین درصد جوانه‏زنی تحت تاثیر دماهای مختلف به ترتیب در تیمار دمایی20/35 (شب/ روز) با 5/98 درصد و 5/15 (شب/ روز) با 38 درصد جوانه زنی مشاهده شد. همچنین، با افزایش میزان شوری از صفر به 80 و 320 میلی مولار درصد جوانه زنی بذور به ترتیب با 42 و 90 درصد کاهش همراه بود. بذور کنگر ابلق در عمق صفر و 1 سانتی متر به ترتیب دارای 35/93 و 37/89 درصد سبز شدن بودند که با افزایش عمق دفن بذور به 8 سانتی متر، درصد سبز شدن نسبت به سطح صفر سانتی متر با 60 درصد کاهش همراه بود. تیمار اسیدیته بر جوانه زنی این گیاه در سطح یک درصد اثر معنی-داری داشت. کمترین (30 درصد) و بیشترین (5/96 درصد) درصد جوانه زنی به ترتیب در اسیدیته 5 و در 8 مشاهده شد. به‏طور‏کلی، نتایج نشان داد که دماهای پایین، سطوح بالای تنش شوری، اسیدیته کمتر و بیشتر از حد خنثی و دفن بذر در سطح خاک و همچنین عمق بیش از 4 سانتی متر برای رشد علف هرز کنگر ابلق محدود کننده می باشد که این اطلاعات می تواند در کنترل بوم سازگار این علف هرز مفید باشد.
    کلیدواژگان: اسیدیته، تنش شوری، سبزشدن، دمای متناوب، عمق دفع بذر
  • مهناز میرزایی، مهدی راستگو، کمال حاج محمدنیا قالی باف، اسکندر زند صفحات 267-276
    به منظور بررسی اثر نمک های بی کربنات سدیم، کربنات کلسیم، کلرور منیزیم و کلرور کلسیم بر کارایی علف کش توفوردی در کنترل علف جارو (Kochia scoparia L.) و تاج خروس ریشه قرمز (Amaranthus retroflexus L.) دو آزمایش جداگانه در سال 1394 در گلخانه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد به صورت فاکتوریل در قالب طرح بلوک های کامل تصادفی با 3 تکرار انجام شد. فاکتورهای آزمایش برای هر علف هرز شامل دز علف کش توفوردی در سه سطح 540، 270 و 135 گرم ماده موثره در هکتار (72% SL)، نوع نمک در پنج سطح (بی کربنات سدیم، کربنات کلسیم، کلرور کلسیم و کلرور منیزیم هر کدام به میزان 500 میلی گرم بر لیتر و آب مقطر به عنوان شاهد) و نیز کاربرد و عدم کاربرد سولفات آمونیوم به میزان دو درصد حجمی بود. 21 روز بعد از سمپاشی درصد بقاء و وزن خشک اندام هوایی اندازه گیری شد. نتایج نشان داد که کاربرد نمک به طور معنی داری کارایی علف کش توفوردی در کنترل علف جارو و تاج خروس ریشه قرمز را کاهش داد. هر چند نوع نمکی که موجب بیشترین کاهش کارایی توفوردی شد بین دو علف هرز متفاوت بود به نحویکه در علف جارو، بی کربنات سدیم نسبت به سایر نمک ها بیشترین کاهش کارایی توفوردی را موجب شد و در تاج خروس ریشه قرمز بین نمک ها اختلاف معنی داری وجود نداشت. براساس نتایج حاصل از این تحقیق پاسخ گونه های علف های هرز به اثرات سختی آب برروی علف کش های اسیدی ضعیف بسته به نوع کاتیون متفاوت است. همچنین کاربرد سولفات آمونیوم در تمامی موارد منجر به غلبه بر اثرات منفی ناشی از حضور نمک در محلول پاشش شد.
    کلیدواژگان: آب سخت، درصد بقاء، کلسیم، ماده افزودنی، منیزیم
  • امه هانی نبوی چاشمی، ساره بقایی راوری، ماهرخ فلاحتی رستگار، کبری مسلم خانی، وحید جهانبخش مشهدی صفحات 277-283
    نژاد 3، بیووار 2 از کمپلکس گونه‏ای Ralstonia solanacearum خسارات اقتصادی قابلتوجهی را به سیبزمینی در سراسر دنیا وارد می‏سازد. بنابراین دستیابی به روش ردیابی حساس و اختصاصی بهمنظور حذف مواد گیاهی آلوده در مراکز تحقیقات و ایستگاه های بازرسی قرنطینه گیاهی ضروری می‏باشد. در مطالعه حاضر پس از جداسازی کلنی های شبیه R. solanacearum از غده های آلوده سیبزمینی در محیط تترازولیوم کلراید، تاییدمولکولی گونه با استفاده از آغازگرهای اختصاصی انجام گرفت. براساس آزمون استفاده از منابعکربنی و واکنشزنجیره‏ایپلیمراز اختصاصی نیز، جدایه های بدستآمده متعلق به بیووار 2 و فیلوتایپ II می‏باشند. آزمون بیماریزایی بر روی گیاهچه های سیبزمینی و گوجهفرنگی برای جدایه ها انجام و بیماریزایی جدایه ها بررسی گردید. ارزیابی غده های آلوده و یا مشکوک به آلودگی با اعمال PCR سنتی و واکنش LAMP بر روی ژن fliC با استفاده از DNA‏ی استخراجشده و عصاره آلوده سیبزمینی انجامگرفت. الگوی نردبانی محصولات LAMP و ردیابی چشمی رسوب پیروفسفات و یا تغییررنگ ایجادشده در نمونه های آلوده به واسط کاربرد کالسئین، دلالتبر ردیابی موفق R. solanacearum توسط واکنش LAMP دارد. اگرچه حساسیت آزمون LAMP (CFU/ml 104) مساوی و یا کمتر از PCR سنتی است، اما دقت واکنش مزبور جهت تایید قابل اطمینان وجود R. solanacearum در غده های سیبزمینی کافی می‏باشد. درمجموع، آزمون LAMP به همراه مرحله آشکارسازی کارایی چون استفاده از کالسئین، اطلاعات اولیه مناسبی را جهت غربالگری غده های آلوده قبل از انبارداری و در حین حملونقل استانی مهیا می‏سازد.
    کلیدواژگان: آلودگی پنهان، پوسیدگی قهوه ای، ردیابی چشمی، fliC، LAMP
  • الهام الهی فرد، ابوالفضل درخشان، حشمت الله زرین جوب صفحات 284-295
    برآوردهای انجام شده در مزارع گندم ایران حاکی از آن است که علف های هرز کشیده برگی مانند یولاف وحشی و برخی پهن برگ ها مانند خردل وحشی نسبت به علف کش های بازدارنده آنزیم استیل کو آنزیم آکربوکسیلاز (ACCase) و استولاکتات سینتاز (ALS) مقاوم شده اند. بنابراین وضعیت مقاومت به علف کش های بازدارنده ACCase و ALS در مزارع گندم شهرستان شوشتر در سال 1393 بررسی شد. بدین منظور بذور خردل وحشی، فالاریس و یولاف وحشی از مزارع جمع آوری و نقاط توسط دستگاه GPS ثبت شد. آزمایش های غربالگری به دو شیوه بررسی دانهال ها در پتری دیش و گیاهچه ها در گلدان با غلظت های تفکیک کننده و توصیه شده 5 علف کش کلودینافپ-پروپارجیل (08/0 ED80=و 25/1ED90=)، تری بنورون- متیل (15 گرم ماده موثر در هکتار)، سولفوسولفورون (95/19 گرم ماده موثر در هکتار)، مزوسولفورون- متیل+ آیودوسولفورون- متیل- سدیم+ مفن پیر دای اتیل (18 گرم ماده موثر در هکتار) و توفوردی+ ام سی پی آ(200 گرم ماده موثر در هکتار) انجام شد. نتایج نشان داد که توده های خردل وحشی به میزان 68 درصد نسبت به آیودوسولفورون- متیل- سدیم + مزوسولفورون- متیل + مفن پیر دای اتیل، 86 درصد تری بنورون-متیل و سولفوسولفورون و صفر درصد توفوردی مقاوم بودند. توده های یولاف وحشی و فالاریس به میزان 87 درصد و 68 درصد نسبت به علف‍کش کلودینافپ-پروپارجیل مقاوم بودند.
    کلیدواژگان: سیستم موقعیت یاب جهانی، غربالگری، غلظت تفکیک کننده و توصیه شده
  • زهرا وکیلی زارج، کامران رهنما، سعید نصرالله نژاد، احد یامچی صفحات 296-311
    بیماری ساق سیاه کلزا (Leptosphaeria maculans) از بیماری های مهم اقتصادی در استان های شمال ایران می باشد. شاخص های ریخت شناسی و فیزیولوژیکی 72 جدایه جمع آوری شده طی سال 94-1393، به منظور شناسایی عامل بیمارگر پر آزار L. maculans در شمال ایران تعیین شده است .جدایه ها در اکثر موارد دارای رشد کند همراه با تشکیل پیکنیدیوم در محیط کشت و تولید رنگدانه به رنگ های متغیر زرد تا سیاه در محیط کشت مایع در دما 18 درجه سلسیوس در تاریکی بودند. جدایه ها در سطح مولکولی نیز به کمک تکثیر با استفاده از واکنش زنجیره ای پلیمراز در ناحیه ی فاصله ی ترانویسی شده ی داخلی 1، 2 و 8/5 اس آر ان ای ریبوزومی از ژنوم با جفت آغازگر اختصاصی LmF و LmR شناسایی شدند. تعدادی از جدایه ها نیز بر اساس تعیین توالی ناحیه ITS-5/8SrRNA و مقایسه با جدایه های موجود در ژن بانک به عنوان L. maculans برای اولین بار تایید و ثبت شدند. جدایه ها از نظر تیپ بیماری زایی با استفاده از آغازگرهای اختصاصی تیپ بررسی شده و گروه بیماری زایی جدایه های انتخابی با تلقیح آنها بر روی سه رقم استاندارد مورد بررسی قرار گرفت. چهار گروه بیماری زاPG-2 ،PG-3 ، PGT و PG-4در جدایه های مهاجم دیده شده است. بیشتر جدایه های مورد بررسی بر روی هر سه رقم افتراقی بیماری زا بوده و در گروه PG-4 قرار گرفتند، که برای اولین بار از ایران گزارش می شود. نتایج پیشنهاد می کند که جدایه L. maculans (PG-4) به عنوان گروه پر آزار و با توجه به تغییرگروه بیماری زایی PG-2 به PG-3 و PG-4 نسبت به سال های قبل، تهدید مهمی برای صنعت کشت کلزا در شمال ایران می باشد.
    کلیدواژگان: آغازگر اختصاصی، ریخت شناسی، گروه های بیماری زایی
  • خدیجه عباسی، دوستمراد ظفری صفحات 312-321
    با توجه به اهمیت بالای سیب زمینی در استان همدان به عنوان قطب تولید سیب زمینی بذری و خوراکی در ایران و این که نماتد Globodera rostochiensis یکی از مخرب ترین و خسارت زاترین بیماری هایی است که این محصول را مورد هجوم قرار می دهد ارائه راه کارهای مدیریتی مناسب جهت کنترل این بیماری بسیار ضروری به نظر می رسد. در این تحقیق، ارزیابی آنتاگونیستی 34 جدایه از 11 جنس قارچی جدا شده از نماتد سیست طلایی موجود در مزارع آلوده ی سیب زمینی استان همدان در شرایط آزمایشگاه و گلخانه مورد بررسی قرار گرفت. ارزیابی در شرایط آزمایشگاه به صورت اندازه گیری قطر هاله در محیط کیتین آگار و محاسبه درصد تخم و لارو پارازیته شده در محیط آب آگار و همچنین در شرایط گلخانه به صورت بررسی فاکتورهای رشدی سیب زمینی تحت تاثیر آنتاگونیستی جدایه های قارچی بر نماتد، انجام شد. نتایج به دست آمده از شرایط آزمایشگاه و گلخانه تا حد زیادی همبستگی داشتند و هم دیگر را تایید کردند. نتایج حاصل نشان دهنده اثر مثبت جدایه های مختلف قارچیدرکاهش بیماری زایی و خسارت نماتد بود.در نهایت جدایه های برتر، جدایه151 (Beauveriabassiana)، 152(Lecanicilliummuscarium)،153 (Paecilomyces lilacinus)و 154(Trichoderma atroviridae)به عنوان موثرترین و قوی ترین قارچ های آنتاگونیست در کنترل این نماتد انتخاب شدند.
    کلیدواژگان: پارازیته کنندگی، صفات عملکردی، کنترل بیولوژیک، کیتین آگار
  • رحمان خاکزاد، محمد تقی آل ابراهیم، احمد توبه، مصطفی اویسی، رضا ولی الله پور صفحات 322-336
    پیش بینی رویش بالقوه گونه های مختلف علف هرز یک نیاز اساسی در توسعه راهبردهای مدیریت تلفیقی آفات برای کنترل علف های هرز است. از این رو برای پیش بینی الگوی رویش گونه های مختلف علف های هرز تحت عملیات مختلف مدیریتی آزمایشی به صورت کرت دو بار خرد شده در قالب بلوک های کامل تصادفی در 3 تکرار در شرکت دشت ناز ساری در سال 1395 اجرا شد. تیمارهای مورد بررسی شامل دو سیستم خاک ورزی (کاشت بدون خاک ورزی و کاشت پس از آماده سازی زمین با دیسک + سیکلوتیلر)، سه تراکم 20، 30 و 40 بوته در متر مربع سویا و دزهای مختلف علف کش ایمازاتاپیر (پرسوئیت) (صفر، 50 درصد، 75 درصد، دز توصیه شده و 25 درصد بالای دز توصیه شده) بودند. تابع لجیستیک سه پارامتره روند کلی الگوی رویش علف های هرز مختلف را در برابر زمان دما (TT) به خوبی توصیف نمود. نتایج نشان داد به جز قیاق که در تیمار خاک ورزی پایین ترین تجمع گیاهچه را دارا بود بقیه گونه ها که همگی پهن برگ بودند در تیمار بدون خاک ورزی کمترین تجمع گیاهچه را داشتند. همچنین نتایج نشان داد که کلیه گونه های علف هرز در تراکم 40 بوته در متر مربع سویا و دز 25/1 لیتر در هکتار علف کش ایمازاتاپیر پایین ترین تجمع گیاهچه را به خود اختصاص دادند. در مجموع در بین سایر گونه ها تاج خروس با داشتن کمترین میانگین زمان رویش و دریافت درجه روز رشد پایین تر، سریعتر به 50 درصد رویش تجمعی گیاهچه دست یافت. از طرف دیگر گاوپنبه نیز با داشتن بیشترین میانگین زمان رویش و دریافت درجه روز رشد بالاتر، دیرتر از سایر گونه های مورد مطالعه به 50 درصد رویش گیاهچه رسید. بر این اساس مرحله رشدی مناسب برای کنترل تاج خروس هنگامی است که هنوز موج اصلی گیاهچه های گونه های غالب دیگر رویش پیدا نکرده اند. نتایج حاصل از این تحقیق اطلاعات ارزشمندی در پیش بینی زمان رویش علف های هرز سویا فراهم می کند که می تواند در برنامه مدیریت علف های هرز و گیاه زراعی مورد استفاده قرار گیرد.
    کلیدواژگان: الگوی رویش، تراکم، خاک ورزی، دز علف کش
  • مسعود لطیفیان، غلامرضا کجباف والا صفحات 337-351
    در این پژوهش روش های مختلف رهاسازی تلقیحی کفشدوزک StethorusgilvifronsMulsan برای مهار زیستی کنه تارتن خرما Oligonychusafrasiaticus McGregor با استفاده از طرح آشیانه ای در منطقه شادگان استان خوزستان مقایسه شد. آشیان های اصلی شامل سه زمان رهاسازی همزمان، سه روز و یک هفته پس از ظهور کنه در نخلستان بودند. آشیان های فرعی شامل سه سطح مختلف رهاسازی حداقل، متوسط و حداکثر با تعداد 5/0، 1 و 3 عدد کفشدوزک در هر مترمربع به صورت روزانه که به مدت 2 هفته ادامه داشت. این آزمایش دارای سه تکرار بود. هر تکرار شامل یک نخلستان ربع هکتاری با نخل خرمای رقم سایر بود. نتایج نشان داد بین تیمارهای مختلف رهاسازی از نظر میانگین فصلی جمعیت و سرعت رشد کنه تارتن و تعداد کفشدوزک فعال اختلاف معنی داری در سطح احتمال 1 درصد وجود دارد. روش رهاسازی با تراکم حداکثر و همزمان با ظهور کنه به عنوان مناسب ترین روش رهاسازی کفشدوزک بود. زیرا در این روش کفشدوزک دارای بالاترین سرعت رشد (09/0) و کنه تارتن کمترین سطح تعادل جمعیت (216/0) بود. همچنین نتایج نشان داد که هر چه زمان رهاسازی به زمان شروع فعالیت کنه تارتن نزدیک تر و تعداد کفشدوزک رهاسازی شده در واحد سطح افزایش یابد، کارایی کفشدوزک در کنترل جمعیت آفت افزایش می یابد. به طوری که بالاترین کارایی در تیمار رهاسازی حداکثر و همزمان با شروع فعالیت کنه (27/83 درصد) بوده است.
    کلیدواژگان: تعداد و زمان رهاسازی حمایتی، کفشدوزک ریز سیاه، کنه تارتن نخل خرما
  • زریر سعیدی، فرنوش نوری زاده، حمید قاجاریه صفحات 352-355
    شته مومی کلم BrevicorynebrassicaeL. یکی از آفات مهم مزارع کلزا در ایران است. بررسی تغییرات جمعیت و خسارت این حشره روی 7 رقم و هیبرید کلزا (شامل ارقام: Okapi،Licord ،Talaye،Modena، Tasilo و هیبریدهایHyola308 وHyola401)، در شرایط مزرعه (در قالب طرح بلوک های کامل تصادفی) نشان داد که خسارت آفت از فروردین شروع و در اردیبهشت ماه در مرحله گلدهی گیاه به اوج می رسد. بیشترین جمعیت آفت روی رقم Talaye و کمترین آن روی هیبرید Hyola401 مشاهده شد.مقایسه میانگین عملکرد و اجزای عملکرد ارقام و هیبریدهای مختلف کلزا نشان داد که بیشترین تعداد خورجین در هیبرید Hyola401، اما بیشترین تعداد دانه در خورجین، بیشترین وزن هزار دانه و بالاترین عملکرد در رقم Tasilo دیده شد. در حالی که کمترین عملکرد و اجزای عملکرد در رقم Modena مشاهده گردید. به طور کلی نتایج نشان داد که رقم Tasilo، مناسب ترین و رقم Modena نامناسب ترین رقم برای کاشت در منطقه شهرکرد می باشند.
    کلیدواژگان: تغییرات جمعیت، شته مومی، عملکرد، مقاومت
  • اکبر علی وردی، ابراهیم ایزدی دربندی صفحات 356-361
    جستجو جهت پیدا کردن مواد طبیعی که استعداد کاربرد به همراه مواد شیمیایی کشاورزی را داشته باشد از اولویت های پژوهشی در زمینه کاربرد این مواد می باشد. از اینرو، یک آزمایش واکنش به مقدار علف کش تحت شرایط گلخانه ای جهت بررسی فعالیت فعالیت روغن های اسانسی سیاه دانه، رازیانه، کندور و گل سرخ، هر کدام در دو غلظت 5/0 و 1 درصد حجمی/حجمی(v/v)، در بهینه سازی کارایی علف کش ایمازتاپیر بر روی علف هرز تاتوره اجرا شد. بر اساس شیب منحنی های واکنش به مقدار علف کش، اگر تمامی این مواد افزودنی در غلظت های مورد بررسی به تنهایی و بدون علف کش به کار برده شوند، از نظر زیستی بر روی تاتوره غیر فعال خواهند بود. وقتی که این مواد افزودنی به محلول پاشش علف کش ایمازتاپیر افزوده شد، بهبود معنی داری در کارایی آن مشاهده شد. در بین مواد افزودنی مورد بررسی، تنها در مورد روغن سیاه دانه، افزایش غلظت ماده افزودنی سبب بهبود معنی داری در کارایی علف کش شد. بر اساس داده های وزن تر تاتوره، کارایی ایمازتاپیر با کاربرد 1 درصد (v/v) از روغن رازیانه تا حدود 61/4 برابر بهبود پیدا کرد. در حالی که، بر اساس داده های وزن خشک تاتوره، کارایی ایمازتاپیر با کاربرد 1 درصد (v/v) از اسانس کندور تا حدود 50/4 برابر بهبود پیدا کرد. این تحقیق ثابت کرد که مواد طبیعی مورد بررسی دارای استعداد قابل توجهی در بهبود کارایی علف کش ایمازتاپیر در کنترل علف هرز تاتوره می باشند. بنابراین، این مواد را می توانند به عنوان مواد افزودنی با پایه گیاهی مناسب بکار برد.
    کلیدواژگان: روغن اسانس، علف کش، مواد افزودنی
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  • S. Fatemi, M. A. Samih Pages 179-190
    Introduction
    Aphids are tiny soft-body insect pests which damage the host plant directly through sap feeding and indirectly by transmission of plant viruses. Pomegranate green aphid, Aphis punicae is a common pest of pomegranate gardens in Iran. In some years, the aphid dramatically damages under the suitable conditions in that they can grow and reproduce. Lady beetles are small, brightly colored insects and belong to family Coccinellidae. These predators obtain necessary resources for their survival and reproduction from a variety of habitats. Menochilussexmaculatus (Col.: Coccinellidae) is one of the major predators of pests reported in the gardens of Iran. The zigzag beetle is a general entomophagouscoccinellid that feeds upon soft body insects such as aphids. The adults of M sexmaculatus are bright yellow in color with black vertical zigzag lines. The adults and larva prey upon all stages of aphids. The study of the predation efficiency of M. sexmaculatus would increase its chances to be used as a biological control agent M. sexmaculatus is an efficient predator of many aphid species, e.g. the mustard aphid, LipaphiserysimiKalt. The zigzag, beetle widely distributed and feed on aphid species in India, Pakistan, Borneo, Jawa Indonesia, and the UK. The Philippines, Islands of Bali, France, Sumatra and South Africa. In this paper, we evaluated the effect of temperature on some biological parameters of M. sexmaculatus by feeding on pomegranate green aphid, A.punicae. Menochilussexmaculatus is an effective predator to be used as a bio-control agent but the major challenge is its mass rearing and augmentation
    Materials And Methods
    The colony of M. sexmaculatus was established from about 100 adult beetles collected from a pomegranate orchard (GPS coordinates 30°23'42.31'' N and 55°56’51.11’ E) at Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran, in October 2013.. Adults were held In a ventilated plastic box (25.0 x 20.0 x 10.0cm) and fed by pomegranate green aphids in a climate-controlled growth chamber set to 25 ± 2 °C, 65 ± 5% RH and 16L: 8D photoperiod. The functional response of different stages of M.sexmaculatus to different densities of 3rd and 4th nymphal stages of pomegranate green aphid were studied at temperatures of 20, 22.5, 25, 27.5 and 30 (±1)°C, for adult females (10-days old) in temperatures of 25 and 27.5(±1)°C for 3rd and 4th larval stages, at 65 ± 5 RH and 16:8 L: D photoperiod. The densities of 2, 4, 8, 16, 32, 64, 100, and 128 3rd and 4th nymphal stages of aphid for 3rd and 4th larval stages and densities 8, 16, 32, 64, 100 and 128 for female and male adults. Females of lady beetle were used and the average feeding at any density was recorded after 24h. Type of functional response was determined using logistic regression and the searching efficiency (a) and handling time (Th), were estimated by nonlinear regression. All the data in the Excel 2007 program was set. Curves and graphs were plotted using Excel 2007 software.
    Results And Discussion
    Type of the functional response of the all predator stages across all temperatures was type II. The results showed that the temperature is effective on functional response of predator, and searching efficiency of predator increased at temperatures of 22.5°C to 27.5°C. The maximum and minimum value of the searching efficiency were0.14 h-1 at 27.5°C and 0.0582 h-1 at 22.5°C and of handling time were 0.26 h at 20°C and 0.0182h at 22.5°C for adult females respectively.
    Conclusion In general, the lady beetle at temperature of 27.5°C and in stages of 4th larval and adult would have the highest predatory efficiency. Application of this predator was interested in biological control programs of pomegranate green aphid. The data indicated that the M. sexmaculatus may be a useful candidate for the biological control of A. punacaein pomegranate gardens.
    Keywords: Functional response, M. sexmaculatus, Pomegranate green aphid, Temperature
  • S.H. Mousavianzabi Pages 191-198
    Introduction
    Canola (Brassica napus L.) is one of the prominent oil seed plants in Iran. This plant has good agricultural and food nourishment properties, such as resistant to drought, cold and salinity stresses and low level of cholesterol. Cabbage waxy aphid Brevicorynebrassicae (L.) is the most important and cosmopolitan pest of cruciferous crops. This aphid is reduced 9 to 77% grain yields and up to 11% oil content. Developing environmental-friendly methods, such as deploying insect-resistant varieties to pest control was advised by scientists. Resistant varieties decrease production costs and can be integrated with other pest control policies in IPM programs. In a greenhouse experiment plants of cabbage, cauliflower wassusceptible host plant and broccoli, turnip, rapeseed, showed resistance to cabbage aphid. With the aim of identifying the existence of resistance resources, a laboratory study was conducted to evaluate the effects of seven canola genotypes on biological parameters of cabbage aphid. Detected resistant variety could be used as a resistance source.
    Material and
    Methods
    In order to resistancy evaluation of canola, genotypes contain “RGS”,“Hyola-308”,“Hyola-401” and “Sarigol” to cabbage aphid, two experiments was conducted under field and greenhouse conditions in Kahriz region of West Azerbaijan province in 2010.In this study infestation index and tolerance in Field conditions and antibiosis study in greenhouse conditions was evaluated.To study antibiosis, genotypes were planted in pots with 10 replications based on completely random design and cabbage aphid population intrinsic rate of increase (rm) was calculated. As followed: (Lotka 1924): 1= other population parameters computed by Carey (1993) method.
    Field experiment contains10 replications wereperformed based on complete randomized blocks experimental designs that five of them were under natural infestation and five others, free of infestation (control). To evaluate the mechanism of genotype resistance, infestation index and functional yield loss in the field was used. Infestation rate was measured as followed:Ii = P × L × N
    P was the percentage (%) of infested canola plant, L; mean length (cm) of infested stem and N; the number of aphid at per centimeter. Infestation indices values were normalized with . To calculate mean length of infested stems, 10 plants were selected randomly each plot. For measuring of mean aphid population per centimeter, 100 infested stems were randomly selected. Infestation percentage obtained with the accounting of infested plants on plots, that had more than one-centimeter infestation. Functional yield loss calculated as followed:Functional plant loss Finally, PRI calculated (Webster et al., 1987). Combined analysis of variance was done byMSTAT-C software. Also, excel was used to drawing charts and some calculations.
    Results And Discussion
    ANOVA of the normalized data showed the highly significant differences (p≤1%) in infestation index rates among the studied genotypesand sampling times. The analysis of the resulted data of yield loss and its component indices based on Complete Random Blocks Design indicated significant differences (p≤1%) between genotypes. The simple ANOVA of theantibiosis experiment data indicated significant differences (p≤1%) in population intrinsic rates of growth (rm) of cabbage aphid. Finally, the genotype of “Sarigol”had the highest Plant resistance index (PRI) in comparison withother genotypes. Intrinsic rate of increase (rm) depends on the percentage of surviving nymph, developmental time, duration of nymph and fecundity of insect. Therefore this character is an important component of resistance to reflect antibiosis effects and determining the degree of resistance. In their experiment, Okapi was known resistant genotype. To evaluate canola genotype resistance to cabbage aphid different methods were applied by researchers including: number of existence colonies and aphid in primary of infestation stage, colonies with more than two centimeters infestation and index that contains the percentage of infestation in a plot multiplied by means of infected stem length.
    Yield and yield loss are the main factors that can indicate tolerance or susceptibility of genotypes. In PRI evaluation all case of genotypes resistance to pest such as antibiosis, antisenseand tolerance was studied, it seems PRI is a good method to know resistance degree of genotypes.
    Keywords: Antibiosis, Infestation index, Plant resistance index, Tolerance, West Azerbaijan
  • E. Mohajeri, N. Panjehkeh, M. Ghorbany, N. Khezrinezhad Pages 199-212
    Introduction
    Grapevine belongs to the Vitaceae family that consists of 14 genera and about 700 species. Only in the genus Vitis fruits are edible. Italy is the largest producer of grapes and Iran has the seventh position in the world from this point of view. Western Azarbaijan province comprises a high diversity of crops including wild grapes. Although, some nematodes are free living and antagonists of another soil microfauna, the other are plant parasitic agents. Most of which live in the agricultural soils where they are widely dispersed. Effectiveness of the disease management strategies are affected by the accurate identification of the plant disease causal agents and the nematodal diseases are not the exception from this rule. Therefore, for control of the diseases caused by the nematodes, it is necessary to separate the parasitic nematodes from the suspected contaminated soils and identify them. Although separation and identification of the nematodes are partly time-consuming, it is not very complicated. Some nematodes likeXiphinema, Longidorus and Ditylenchus are cosmopolitan and catastrophic nematodes in vineyards worldwide. So far no study has been performed regarding the plant parasitic nematode in vineyards of the south of Western Azerbaijan. Therefore, in this study as an introduction to the management ofthe vineyard parasitic nematodes, the dominant nematodes of the plant were identified. In the next step, investigation of nematodes bioecology, the interaction of nematodes with the other plant pathogens, their host range and their damages to the host plants would be studied.
    Materials And Methods
    In order to identify the fauna of plant parasitic nematodes in vineyards of the south of Western Azarbaijan, during 2013-2014, 50 soil samples were collected from the rhizosphere of grapevine. The sampling was carried out from the vineyards of five grapevine growing cities including Mahabad, Bookan, Sardasht, Piranshahr and Miyandoab. The samples were collected from the rhizosphere of grapevines from the depth between 10 and 80 cm from the soil surface after digging and separating the surface dry soil. About 2 kg soil from each vineyard from several places were collected and by means of a plastic bag was transferred to the laboratory where they were kept in the refrigerator at 4-degree centigrade until used. Nematodes were extracted from the soil by combined sieving and centrifugal-flotation method and processed to be transferred to glycerin. After preparing microscopic slides, the morphological and morphometrical features of the nematodes were studied using the light microscope equipped with a drawing tube. Identification of the genera and species was performed using reliable sources and valid nematode identification keys and the morphological features. The measurements of the extracted nematodes were compared with those ones given in literature and their similarities and differences with original descriptions and closest species were discussed.
    Results And Discussion
    As a result, 23 species belonging to 15 genera including Amplimerliniusglobigerus, Basiriatumida, Boleodorusthylactus, Discotylenchusdiscretus, Ditylenchusacutus, Ditylenchusmyceliophagus, Filenchus vulgaris, Geocenamusbrevidens, Geocenamusrugosus, Helicotylenchuspseudorobustus, Helicotylenchus vulgaris, Mesocriconemaantipolitanum, Mesocriconemaxenoplax, Paratylenchuslabiosus, Pratylenchoidesvariabilis, Pratylenchuscoffeae, Pratylenchusneglectus, Pratylenchuspenetrans, Pratylenchussefaensis, Praylenchusscribneri, Scutylenchuspaniculoides, Xiphinema index andZygotylenchusguevaraiwere identified. Five isolated species namely, Helicotylenchus vulgaris,Mesocriconemaantipolitanum, Mesocriconemaxenoplax, Helicotylenchuspseudorobustusand Pratylenchusneglectus respectively based on the frequency and distribution in the soil samples are determined as dominant parasite species. Here, the two more dominant species, Helicotylenchus vulgaris and Mesocriconemaantipolitanum are a little bit described. Helicotylenchus vulgaris, initially worldwide was reported by Yuen in 1964 and for the first time from Iran in 1995 was reported by KargarBideh, and his collaborators from Hamdan province. The species from morphological and morphometrical characteristic point of view is very close to Helicotylenchusminzi.Mesocriconemaantipolitanum firstly in 1991 was reported from Iran by Loof and Barooti from apple, wheat and lucerne roots from Karaj, potato from Lorestan, lucerne from Zanjanand apricot from Northern Azarbaijan. In the research, the species was isolated from Piranshahr, Miyandoab, Bookan and Mahabad vineyard cities of Western Azarbaijan. The species is very similar to M. surinamense.
    Conclusion
    Nine species including Discotylenchusdiscretus, Ditylenchusacutus, Ditylenchusacutus, Paratylenchuslabiosus, Pratylenchoidesvariabilis, Pratylenchuscoffeae, Pratylenchuspenetrans, Pratylenchusscribneri, Pratylenchussefaensisand Scutylenchuspaniculoides were recorded for the first time from the rhizosphere of grapevine from Iran. Considering thatall the nematodes are already recorded from Iran, herein only the dominant species are described.
    Keywords: Grapevine, Morphology, Rhizosphere
  • M. H. Ranjbar, J. Gherekhloo, A. Soltani Pages 213-222
    Introduction
    Weed control is the most important challenge for adoption of conservation tillage systems. Tillage prepares optimum conditions for growth and development of crops. Conservation tillage compared with conventional tillage has many advantages in terms of improving soil conditions and soil moisture retention. Nevertheless, during the preparation of seed bed, decreasing of soil disturbance in different conservation tillage methods could be resulted in optimal conditions for growth of various weeds. Although each of the conservation tillage methods affect on weed population dynamics and change weed density and diversity, the effects of tillage systems on weed dynamics and diversity depend upon species, location and environment which is complex and not fully understood.
    Materials And Methods
    To investigate the effect of different tillage systems (Conventional, Minimum tillage and No-tillage) on diversity and evenness of weeds at beginning and end of critical weed control period in forage corn field, a study was conducted in a Nested design in Azadshahr during 2013 growing season. The experiment consisted of three methods including no-tillage, reduced tillage (once or twice a composite disk tillage) and conventional tillage (moldboard plowing once and three times the disk). The experiment was done in three separate plots and the size of each plot was 1500 m2. 15 samples were selected in each plot using a 1*1 m2 quadrate and number of weeds species were counted, separately in each plot. Fifteen kg. ha-1 seeds of corn cultivar SC 770 was planted at 01/07/2013 for all tillage systems. Row spacing and distance of seeds on rows considered as 75 and 14 cm, respectively and seeds were buried in 4-5 cm in all studied tillage systems. 15 samples were selected in each plot using a 1*1 m2 quadrate and number of weeds species were counted, separately in each plot at begging and end of critical weed control period (CWCP).Data Analyses
    To calculate Simpson's diversity index weve used relation 1 (10):(1)
    In above relation: 1-D: Simpson's diversity index; ni: number of people at ith variant; nj: number of people at jth variant; N: Number of all people; S: Number of all variants, at sample has been showed.
    To calculate Camargo uniformity index weve used relation 2 (10):(2)
    In this relation: E': Camargo uniformity index; ni: number of people at ith variant; nj: number of people at jth variant; N: Number of all people; S: Number of all variants, at sample has been showed.
    To calculate Rencon Similarity index weve used relation 3 (22):(3)
    In this relation: P: percentage of samples 1 and 2 similarity; p1i: percentage of "i" variant exist at sample community number1; p2i: percentage of "j" variant exist at sample community number2.
    Drawing of all regressions in these studies, calculation of uniformity index, similarity index has been made by Excel. SAS software has been used to fit regressions.
    Results And Discussion
    Simpson diversity index (SDI) at the beginning of the critical period for no-tillage system Determined as 0.30 whichwas less than SDI of the other two tillage systems. However, at the end of CWCP, amount of SDI for conventional tillage system (0.40) was less than minimum and no-tillage. Camargo uniformity index was determine 0.16 and 0.24, 0.16 and 0.20, 0.20 respectively at beginning and end of CWCP for no-tillage, conventional and minimum tillage systems, respectively. Results revealed that weeds at the end of CWCP and in no-tillage system have more evenness than other two tillage systems. The results showed that at least two of tillage and conventional tillage, for the beginning and end of the critical period of weed diversity, there was little difference. But no-tillage system at the critical period of weed diversity was lower than the critical period.The results showed that at least two of tillage and conventional tillage, for the beginning and end of the critical period of weed diversity, there was little difference.But no-tillage system at the critical period of weed diversity was lower than the critical period.Alsothe minimum value for the no-tillage system and obtained weed diversity at the beginning of the critical period.The highest diversity of weeds for no-tillage system at the end of the critical period.Similarity index showed thatgrown species at the beginning of the season until the end of the critical period, growth was sustained in the field but no-tillage system as much similarity in the beginning and end of the critical period was only 35 percent; this suggests that the species composition of weeds in no-tillage system is dynamic in time.
    Conclusion
    Thanks to my wife on the cheek counting and measurement of dry weight species helped me.
    Keywords: Camargo index, Critical weed control period, Simpson index, Tillage system
  • H. Hammami, R. Ghorbani, A. Aliverdi Pages 223-231
    Introduction
    The genus of oat contains several species often infesting both wheat and barley fields all over the world. They compete tightly with these crops for space, water, nutrients, and light. Due to a continuous high selection pressure, herbicide resistance to ACCase inhibitors developed in wild oat populations. Accordingly, these observations approved the necessity of replacement of ACCase-inhibiting herbicides with other herbicide modes of action. The sulfonylurea herbicides were assessed as good alternatives for this purpose. Due to sulfonylurea herbicides ability to control a broad spectrum of grass and broad-leaved weeds, combined with their low application rate and low mammalian toxicity. The efficacy of herbicides can be enhanced using surfactants (1 and 18).
    Materials And Methods
    This pot experiment was repeated twice during 2013 at Ferdowsi University of Mashhad, Iran; once in greenhouse conditions and once in outdoor conditions.
    An experiment was separately conducted with each herbicide which repeated one in glasshouse and one outdoor. The treatments were include: sulfosulfuron at 0, 2.5, 5, 10, 15, and 20 g a.i. ha-1 (Apyrous® WG, 75% sulfosulfuron); and metsulfuron-methyl sulfosulfuron at 0, 5.625 (0.351.273), 11.25 (0.703.546), 22.5 (1.406.094), 33.75 (2.109.641), and 45 (2.813.187) g a.i. ha-1 (Total® WG,5% metsulfuron-methyl 75% sulfosulfuron). Each of these doses was applied alone or with the surfactants of nonionic and cationic surfactants at two concentrations of 0.1% and 0.2% (v/v). The spray treatments were applied at the four-leaf stage using a calibrated moving boom sprayer (Matabi 121030 Super Agro 20 L sprayer; Agratech Services-Crop Spraying Equipment, Rossendale, UK), equipped with an 8002 flat fan nozzle tip delivering 200 L ha-1 at a pressure of 200 kPa. A capillary rise technique was used to measure the static surface tension of aqueous solutions.
    Results And Discussion
    The tap water surface tension was recorded 68.61 mN m-1. The data from this study showed that both surfactants were effective at lowering the surface tension of all spray solutions; however, nonionic surfactant was more effective than cationic surfactant.Difference among the surface tension of herbicides may be related to the difference in their formulations. Aliverdi et al. (2009) observed that clodinafop-propargyl (emulsifiable concentration (EC) formulation) reduced the surface tension of distilled water more than tribenuron-methyl (dry flowable (DF) formulation). The performance difference in lowering static surface tension by those two surfactants can be ascribed to their physicochemical properties. The tested nonionic surfactant contains low ethylene oxide [C8H16C6H4(C2H4O)10H], while the tested cationic surfactant contains high ethylene oxide [R-N(C2H4O)7H(C2H4O)8H] in its chemical structure. It is well established by experimental evidence that surfactants with low ethylene oxide content were more effective than surfactants with high ethylene oxide content in decreasing the static surface tension of spray solutions. Sulfosulfuron and metsulfuron-methyl sulfosulfuron dose responses in greenhouse experiments indicated an ED50of 8.94 and 13.13 g a.i. ha-1 for wild oat, respectively. In outdoor experiments, ED50parameter valueswere 13.11 and 27.86 g a.i. ha-1, respectively. These findings suggest two points; firstly, in equivalent doses metsulfuron-methyl sulfosulfuron was lower effect than the sulfosulfuron. Secondly, the herbicide efficacy on wild oat was higher in greenhouse experiments than outdoor experiments. This finding can be related to the difference in traits of plants grown in two different environments, which influences leaf micro-morphology and cuticle thickness. Compared with nonionic surfactant, cationic surfactant had a greater ability to enhance the activity of herbicides tested both in greenhouse and in outdoor experiments. Surfactants ethylene oxide content has an important role in herbicide efficacy. Previous research showed that high ethylene oxide content surfactants often work best with herbicides with high water solubility (log Kow 1) (1, 12, 20).
    Conclusion
    The results confirm the idea that the HLB value can help to select the type of surfactant that is appropriate for a given herbicide. Thus, high-HLB surfactant will be more suitable for water-soluble herbicides than low-HLB surfactant; and vice versa. As judged by data obtained, the tested cationic surfactant with a high-HLB value was more effective to enhance the activity of four herbicides tested with a log Kow
    Keywords: Citogate, Dose-response, Frigate, Metsulfuron-methyl + Sulfosulfuron, Sulfosulfuron
  • M. Sadat Alizadeh, M. Esfandiari (Ms) Mossadegh, M. Mashayekhi Pages 232-241
    Introduction
    The pink hibiscus mealybug, Maconellicoccushirsutus (Green) (Hem.:Pseudococcidae) is one of the serious economic pests of agricultural crops in tropical and subtropical regions.This pesthas spread through Asia, Africa, America and Australia, and infests more than 330 host plants which some of them have the important role in theeconomy. This sap-feeding insect secrets honeydew which provides suitablemedium for black sooty moldgrowth. It also releases a toxin during feeding, which results in severe stunting, decline, and deformation of twigs. It has recorded as a pest on different host plants in southern Iranian provinces since the 1990s.In Khuzestan province, it was first observed on Chinese hibiscus shrubs in urban landscapes of Ahvaz in February 2009. The evergreen hibiscus shrub is very common in the urban landscape of warmcities of Khuzestan province. The severity of mealybug damage to hibiscus shrubs causedto becut off in some regions. As there is no data on the biology of M. hirsutus in Iran,in the present study, the biologyof this pestwas investigatedat different temperatures in laboratory conditions as well as its population fluctuations on Chinese hibiscus shrubs in urban landscapes of Ahvaz.
    Materials And Methods
    Biology of the pest species was evaluated at five laboratory constant temperatures 15, 20, 25, 30and 35±2°C (65±5% RH and a photoperiod of L: D 14:10 h) on Chinese hibiscus leaves in plastic boxes (8×6×2 cm). Number ofM. hirsutusgenerations was also studied in clip cages on hibiscus shrubs in Ahvaz urban landscapes within a year. Population fluctuations of the insect were also investigated on those shrubs in two different regions of Ahvaz for 16 months. For this purpose, random sampling was done on five shrubs in each region bi-weekly. Eight twigs, 5 cm in length, were cut from the upper and lower halves of each shrub quadrant and a number of all mealybug developmental stages per twig were counted and recorded.Analysis of duration of different developmental stages was done by one-way ANOVA. For data analysis means were compared using SPSS 20 at 1% significance level. Data were assessed for normality by Shapiro-Wilkinson test in SPSS, and Anderson-Darling test in Minitab15 at 1% significance level.
    Results And Discussion
    Total life span ofthe female ofmealybug from egg to death at 20, 25, 30 and 35±2°Cwere 91.18±1.15, 51.68±0.84, 38.18±0.68 and 36.93±0.64 days, respectively. This period for a male was 60.69±1.57, 33.67±0.48, 24.33±0.57and 21.37±0.62days, respectively.No eggs were hatchedat 15°C. The longest and shortest life span of both male and female mealybugs wereat 20 and 35°C, respectively. No female could lay eggs without male and die after amonth. Therefore,matingwas necessary for egg production.However, there are reports of parthenogenetic reproduction in this pest species. An average number of crawlers produced by each female at above mentioned temperatureswere 152.2±6.25, 268.8±7.82, 322.2±6.18 and 240.3±11.86, respectively. The pest produced seven generations on hibiscus shrubs according to clip cage results in Ahvaz the urban area.The average total pre-oviposition period from egg to adult in clip cages in urban area of Ahvaz were 38.67, 34.04, 35.40, 45.21, 39.59 and 67.75 days for 1-6 generations during a year, respectively. Study of the pest population fluctuations showed thatthis pest species overwintered as different developmental stages in crevices of shrub bark. The mealybugs which were hidden in crevices of shrub bark in winter started to occupy the new leaves and twigs in early April.Ants were walking in lines on twigs and around mealybugs in high numbers, indicating the importance of ants in transporting mealybugs from winter shelters to newly grown twigs and leaves in early spring.The moderate temperature in autumn helped the population built up of the pest. Some differencesobservedbetween duration of developmental stages of the mealybug in our study and some previous studies may be arise from the difference in host plants and/or the origin of the studied populations. The 6th and 7th generations occurred in winter with very short developmental time.
    Conclusion
    Because this pest has a potential for spreading through other Iranian provinces, combining the present results with the previousstudieson this mealybug and its natural enemies’interactions in Khuzestan, may provide a perspective for appropriate control of this pest in Iran.
    Keywords: Population fluctuations, Number of generations, Urban landscape
  • Hossein Karbalaei Khiavi, Mohammad Hajian Shahri, Kavous Keshavarz, Hossein Khabbaz Jolfaei, Esfandiar Zohour, Mohammad Bazubandi Pages 242-249
    Introduction
    Fungal diseases are a major problem in the cultivation of grapevine, Powdery mildew disease caused by plant pathogenic fungus, Erysiphenecator is one of the most important and destructive diseases of grape in many countries of the world including Iran. Due to extend viticulture area in Iran and the high prevalence of the grape powdery mildew in vineyards, application of sulfur based fungicides is mainly recommended for the disease control. This study was conducted aimed to investigate the effect of new formulations fungicide of sulfur SC 80% and penconazole EW 20% to control grape powdery mildew disease.
    Material and
    Methods
    The experiments were conducted on Askari cultivar as susceptible in Ardabil, KhorasanRazavi and Kohgiluye and Boyer-Ahmad provinces and in vineyards, which in previous years had a history of infected and trees were similar in age and growth conditions. Experiments were carried out in a completely randomized block design with four replications. Treatments were composed of penconazole EW 20% 0.125 ml L-1, sulfur SC 80% 2, 2.5 and 3 ml L-1 and control. The spray was carried out three times, including when the young shoots were between15 and 35cm, before falling flowers and stage of sours. One week after the last spray sampling of leaves and clusters was carried out in four directions main canopy trees randomly in each plot. Efficacy of treatments was evaluated based on infection severity found in 60 leaves and 12 clusters in per plot. To determine the amount of sugar and tartaric acid in the grape fruit, sampling of the healthy and infected clusters were carried out and healthy and infected the samples were then separated into a plastic bag and crushed. Then, the juice wasprepared (fruit juice was obtained from 700 g fruit in each sample).To determine the amount of sugar, hand-held refractometer was used and the amount of sugar was determined in healthy and infected fruit. For the determination of tartaric acid in grape juice titration using sodium hydroxide, 1.0 M was carried out.
    To determine the yield of grapes per healthy and infected plants and determination of the quantity of the yield damage caused by the disease, after fruit ripening, all clusters of grapes were picked by hand and weighed. Then in each province data were transformed and statistical analysis of data using SAS software was carried out. The mean comparisons were conducted with Duncan's Multiple Range test and Fisher's Least Significant Difference (LSD) test at the 5% level.
    Results And Discussion
    Combined analysis of variance studied traits showed that between locations in terms of severity of disease in leaves and fruits, between treatment and locations and treatment interaction in terms of severity of disease in leaves and fruits, yield there was the significant difference. Analysis of variance amounts of sugar and acid concentration in the grapes in Ardabil (Meshginshahar) showed between treatments in terms of the amount of sugar and acid concentration in grape was observed the significant difference. According to the results sulfur SC 80% fungicide at concentrations of 2.5 and 3 per thousand the greatest effect in reducing the powdery mildew disease and increase yield and quality of grapes. Analysis of variance for amounts of sugar and acid levels in the grapes in Ardabil (Meshginshahar) showed highly significant differences among treatments in grape sugar and acid concentration at 1% level. Comparison of means indicated that control treatment (without spraying) had the highest concentration of sugar and acid. In this study, increasing the severity of the disease on the leaves and fruit tended to increased acid concentration in the fruit. In this study, the yield of the grape was decreased depending on the disease severity on the leaves and clusters. In this experiment, increasing the severity of the disease on the leaves and fruit tended to increased sugar amount. The intensity of infection was higher in the leaves and fruits as well as the amount of sugar in sugar increases that were consistent with findings of another researcher.
    Conclusions
    According to the results and taking into consideration environmental protection, the lowest intensity of infection in the leaves and fruit, the highest yield, the most normal sugar and acid concentration were on the treated plants with the sulfur concentration of 2.5 per thousand. According to the results of this study, spraying sulfur SC 80% in the control programs of the disease to prevent the emergence of resistant races of grape powdery mildew would be desirable.
    Keywords: Disease, Fungicide, Sulfur, Vineyard, Erysiphe necator
  • A. Sheikhigarjan, M. Mohamadizadeh, M.R. Nematyan, F. Zarrani Pages 250-256
    Introduction
    The subterranean termites make large damage to wood and cellulosic products. They can have the destroying effects on forest plantations, agriculture crop, and urban landscaping. According to the previous studies, Microcerotermesgabrielis Weidner is the most important termite of the Alborz province belong to the family Termitidae. This species is also reported in the central, the northeastern and the southern regions of Iran. MicrocerotermesvaraminicaGhayourfar, Amitermesvilis (Hagen), A. kharaziiGhayourfar, Anacantthotermesvagan (Hagan) have been also reported from Tehran province.Chemical control of termiteis the most conventional method ofcontrol. A few insecticides have acceptable termiticide effects. However more of them have negative effects on the other non-targets organisms in the environment, and may run off into groundwater. Thus we wouldconsiderthe other methods of termite control. Usage of native and natural resistant plant species can be reasonable strategy against termitesinafforestation. Plant species are food sources for termites, however, they differ in their palatabilityand can affect termite preference. There are some studies have reported differences in feeding rates and preferences of termite species amongdifferent species of woody plants. Tree Shalamzar Plantation, encompassing 54 ha in the southern Alborz mountain range have sustained termite damage since 2013. The objective of this study was to evaluate the natural resistance of eight different sapling species to termite´s damage in this region.
    Materials And Methods
    Termites were collected from four infested locations within Shalamzar Plantation, Karaj, Iran. Infested saplings with active termite tunnels were visited and soldier termites collected and transferred to the systematics lab for species identification using a systematic key of Iranian termites. Termite infestation rates were estimatedfor each of 8 sapling species. Ten saplings of each species were randomly selected and examined from the four infested locations. Termite-free saplings with no damage or mud tunnels were designated as healthy 'control' plants. Infestation rates were calculated based on the number of infested saplings per total number of each sapling species. The saplings were classified by the termite damage in five categories:1. health (0% damage ) 2. Low ((>0 to 25%) 3. Medium ((>25 to 50%), 4. High ((>50 to 75%) 5. Dead ((>75 to 100%). Data on percentage of infested saplings from each species were subjected to PROC GLM model in completely randomized design. Differences among means were analyzed using LSD Test (P≤0.05). Termite damage was analyzed using the Kruskal–Wallis test. Mean termite damage rates and frequency of damage groups in each plant species were estimated.
    Results
    The results showed that Microcerotermesgabrielis is only damaging termite species on the studied saplings in these regions. Juniper and mountain almond species had no termite infestation and were resistant to its attack. Silverberry and hackberry species were the most susceptible saplings to termite damage with a 65 and57.5 % infestation rate and 60.44 and55 % dead rate, respectively. Judas sapling plants had over 60% termite infestation rate, sustained 20% mortality. It is tolerant species to termite. Ash and barberry species hadless than 50% oftermite infestation and their dead plant rate was 35.42and 28.33 %, respectively. Thus, the species of juniper and mountain almond saplings can be replaced by dead saplings.
    Discussion
    Microcerotermesgabrielis is the primary sapling-damaging pest on the southern Alborz mountain slopes. This is the first report of termite attacking saplings in Iran. Susceptibility of saplings to termite damage varies with termite species. Microcerotermesspp. prefers to feed Faqus sp., whereas Microtermes sp. feeds more Piceasp. and Odontotermes spp.feeds live plant tissue and tree bark. Hackberry and silverberry saplings were preferred by M. gabrielis, whereas the species ofjuniper and mountain almond showed resistant totermite´s infestation. There are many factors affecting termite feeding preference. Wood moisture and densityaffect wood palatability to termite, and some plant chemicalssuch as phenol compoundsand lignin ofwood act as antifeedants and repellents on termite.
    Conclusion
    The species of juniper and mountain almond saplings were the most resistant to M. gabrielis.
    Amongsaplings sustaining damage, Judas tree had also the lowest mortality. So, three species ofjuniper, mountain almond and Judas are recommended to be considered for tree planting in locations where M. gabrielis has infested the soil. It is prudent to identify the predominant tree-damaging termite species in areas designated for afforestation, and determines the plants and trees that are the highest levels of resistant to damage by indigenous termites prior to conducting planting operations.
    Keywords: Afforestation, Alborz mountain, Termite damage
  • E. Zeidali, R. Moradi, A. Ahmadi, M. Hosseini Pages 257-266
    Introduction
    Milky thistle (Silybum marianum) is an annual or biennial plant of the Asteraceae family. Possibly native near the coast of southeast England, it has been widely introduced outside its natural range, for example into North America, Iran, Australia and New Zealand where it is considered an invasive weed.
    Seed is an important stage of plant life history. Most invasive plants primarily rely on seedling recruitment for population establishment and persistence. The rapid spread of many invasive plants is frequently correlated with special seed traits. Seed trait variations exist not only among species but also within species. Seed traits variations within a species are essential for the seedling establishment at different habitats.
    Environmental factors, such as temperature, soil solution osmotic potential, solution pH, light quality, management practices and seed location in the soil seedbank, affect weed seed germination and emergence.
    Fluctuations in temperature can influence seed germination differently than those under constant temperatures; however, such information is not available on Milky thistle. A light requirement for germination is the principal means by which germination can be restricted to an area close to the soil surface, and species requiring light for germination are potentially more likely to be prevalent in no-till and pasture systems. Soil pH affects the development and competitiveness of crops and weeds by affecting the availability of essential minerals, nutrients, the solubility of toxic elements, and soil microflora. Seed burial depth (buried by tillage or other means) also affects germination and seedling emergence of several weed species.
    Better knowledge of the factors that influence seed germination and seedling emergence of Milky thistle could contribute to the development of control measures and help determine its potential for invasion into new areas. The objectives of this study, therefore, were to determine the effect of various environmental factors on seed germination and seedling emergence of Milky thistle.
    Material and
    Methods
    Germination of Milky thistle was determined by placing 25 seed in a 9-cm-diam Petri dish containing two layers of Whatman No. 1 filter paper and moistened with 5 ml of distilled water or a treatment solution.
    Temperature: Germination of freshly harvested seed was determined in growth chambers under fluctuating day/night temperatures (15/5, 20/10, 15/25, 15/30 and 20/35˚ C).
    Salinity: In this experiment, seeds were exposed to seven levels of increasing salinity using NaCl solutions including 0, 10, 20, 40, 80, 160 and 320 mM. Petri dishes were incubated as described in the general protocol under the light⁄dark regime.
    pH: To examine the effects of pH on seed germination, buffered solutions of pH 5 to 9 were prepared.
    Seed burial depth: The effect of different burial depths on seedling emergence was investigated in a growth chamber. Seeds were buried at six different depths (0, 0.5, 1, 2, 4, and 8 cm) in 15-cm-diam plastic pots.
    Statistical analysis: Data were subjected to two-way analysis of variance (ANOVA) and the difference between treatment means was separated using FLSD test. A significance level of 5% was applied by SAS 9.2.
    Results And Discussion
    The results showed that effect of different temperature regimes on germination percentage and rate, plumule length and seedling dry weight were significant (P
    Keywords: Acidity, Emergence, Fluctuating Temperature, Seed burial depth, Salinity
  • M. Mirzaei, M. Rastgoo, K. Haj Mohammadnia Ghalibaf, E. Zand Pages 267-276
    Introduction
    Quality of water used in spray tanks can affect herbicide efficacy, especially acidic herbicides such as 2,4-D. Water is the primary carrier for herbicide applications and it usually makes up over 99% of the spray solution. Considering that, it should be no surprise that the chemistry of water added to the spray tank greatly impacts herbicide effectiveness. Some ions such as calcium and magnesium cations that dissolve into the water, creating various levels of hardness in the water supply. 2,4-D is weak acid herbicide that can be influenced by hard water cations or foliar fertilizers. It has shown reduced activity when applied in water containing calcium and magnesium cations. Hence considering the quality of the water tank sprayer especially hardness helps optimize the efficacy of herbicides. Thus this research was conducted to determine the effect of different salts to 2,4-D on kochia and redroot pigweed as indicator weed species.
    Material and
    Methods
    Greenhouse experiments were conducted during 2014 at Ferdowsi University of Mashhad to determine the effect of sodium bicarbonate, calcium carbonate, magnesium chloride and calcium chloride in 500 ppm and deionized water as the control on the efficacy of 2,4-D in three doses including 135, 270 and 540 g. a.i. ha-1 (SL 72%) with and without ammonium sulfate (AMS) ( 2% w/v). Kochia and Redroot pigweed were planted after breaking dormancy in plastic pots. Herbicide was applied using a backpack sprayer calibrated to deliver 290 L ha−1 at 200 kPa with flat-fan nozzles (Tee Jet 8002 flat-fan spray nozzles). Spray solutions were thoroughly agitated each time a new solution was prepared and immediately prior to application to bring herbicide into solution. Living plants were recorded 3 weeks after herbicide treatment irrespective of the timing of application. In addition to survival, the above-ground dry weight of Kochia and redroot pigweed in each pot was determined 3 weeks after the optimum timing of herbicide application. The experimental design was a randomized complete block with 3 replications. Data were subjected to ANOVA for a factorial treatment arrangement using Minitab ver.17. Means of significant main effects and interactions were separated using Fisher’s Protected LSD test at p≤0.05.
    Results And Discussion
    Results of ANOVA showed that all factors included 2,4-D doses, type of salt and AMS application had significant effects on survival and dry matter of Kochia and redroot pigweed three weeks after treatment. In this experiment, 2,4-D toxicity to Kochia and redroot pigweed was antagonized by salts available in the spray carrier. Reducing in 2,4-D efficacy for Kochia control in the presence of salts such as calcium, magnesium and sodium by Nalewaja and Matysiak (1993b) was reported. In Kochia, sodium bicarbonate was more antagonistic than the others. But there is no difference between inhibitory effects of all salts in redroot pigweed. Mueller et al. (2006) reported that calcium and magnesium concentrations greater than 250 ppm antagonized glyphosate activity on the weeds such as broadleaf signalgrass, pitted morningglory, Palmer amaranth and yellow nutsedge. Nalewaja and Matysiak (1991) showed that the glyphosate toxicity to wheat was antagonized by sodium, calcium, and magnesium. In addition, results indicate that antagonism of salts on 2,4-D efficacy can be overcome by AMS in both two species, Kochia and redroot pigweed. Shahverdiet al. (2009) showed that the activity of the weak acid herbicides such as glyphosate, chlopyralid, 2,4-D increased with the addition of ammonium sulfate to the spray solution. Also, Roskampet al. (2013) showed that the activity of the 2,4-D and dicamba increased with the addition of ammonium sulfate to the spray solution for control of redroot pigweed, grass horse and lambsquarter. Results of interaction effects between 2,4-D dose and type of salt show that by increasing herbicide dose antagonism effects of cations were decreased. According to our results application of ammonium sulfate in on hard water increased the efficacy of 2,4-D four times in Kochia and more than four times in redroot pigweed.
    Conclusion
    The efficacy of 2,4-D on Kochia and redroot pigweed was affected by salt type in the spray carrier. Type of salts was different between two species, in Kochia, sodium bicarbonate had more negative effects and in redroot pigweed each four salts had similar effects. Numerous studies have shown that cations can influence herbicide efficacy depending weed species. Also our results showed that control of Kochia and redroot pigweed increased when AMS was added to 2,4-D in spray solutions. AMS has been considered important to herbicide enhancement or to overcoming herbicide antagonism by salts in spray carrier, AMS also enhance 2,4-D phytotoxicity in the absence of antagonistic salts that this confirm previous reports. It was concluded that weed species responded differently to the inhibitory effects of different cations in spray solution and AMS application, thus making a simple recommendation for all conditions is difficult.
    Keywords: Adjuvant, Calcium, Hard water, Magnesium, Percentage of survival
  • O. H. Nabavi Chashmi, S. Baghaee-Ravari, M. Falahati Rastegar, C. Moslemkhani, V. Jahanbakhshmashhadi Pages 277-283
    Introduction
    Race 3/ biovar 2 of this pathogen causes bacterial blight of solanaceous plants especially potato in both tropical and temperate regions and results in great economic losses worldwide. Infection is prevented via quarantine or incineration of infected plant materials. However, the use of healthy seed tubers is the most effective way to avoid dissemination of this harmful plant pathogenic bacterium to pathogen-free areas. Amplification of functional genes such as endoglucanase and hrpB and fliChas been used as an alternative to study R. solanacearumspecies complex. In order to facilitate detection of R. solanacearumin imported seed tubers and identify high-risk fields and stores where inoculums population is low, loop-mediated isothermal amplification (LAMP) reaction as a potentially fast and cost-effective method was used. The attention of the present study wason evaluation of latent infection in potato tubers with R. solanacearum bacterium targeting the fliC gene by colorimetric LAMP assay. The LAMP protocol was compared with the conventional PCR which routinely used at most quarantine stops.
    Materials And Methods
    In this study, bacterial strains were isolated on tetrazolium chloride (TZC) agar medium. Pathogenicity assay was carried out on tomato and potato seedlings under greenhouse conditions. Total DNA of bacterial strains was prepared using Chen and Kao (1993) protocol. In some cases, the boiled filtrated potato extract was used directly in molecular experiments. Identification of R. solanacearum strains at species and phylotype levels and biovar determination were done based on literature. The PCR products were analyzed on 1.2 % agarose gels in TBE buffer and visualized with UV light. To detect R. solanacearumin symptomatic and symptomless tissues, conventional PCR and LAMP assay according to fliC gene were performed and compared with each other. In order to check amplified LAMP products in visual assessment, the existence of magnesium pyrophosphate precipitate in tested tubes was analyzed. Furthermore, change in colourdue to the reaction was evaluated bynaked eye and UV treatmentafter adding the calcein. Finally, the LAMP products were examined by electrophoresis through 2% agarose gel after staining with green viewer. To determine limit of the LAMP assay, seven dilution series (2×107 to 2×10 CFU/ml) were prepared and 2 μl of each dilution was used for LAMP.
    Results And Discussion
    Bacterial colonies showed mucous and opaque appearance with red centre and whitish periphery on TZC agar medium were selected for further study.In plant bioassay two weeks after bacterial inoculation, different levels of wilting were observed on tomato and potato seedlings.The expected 281 and 372 bp PCR-amplified fragments was observed in all strains supporting species and phylotype identification, respectively. Moreover, utilization of carbon sources indicated that the strains were related to biovar 2. Furthermore, all strains from potato were screened using Ral-fliC and Rsol-fliC primers. A 400 bp PCR product specific to R. solanacearum was obtained from all strains. Sequencing three purified PCR products confirmed the right amplification of fliC gene specific to R. solanacearum.
    The amplified products were detected by visual observation which the white turbidity of the reaction mixture by magnesium pyrophosphate was seen after 55 min. An alternative indicator to visually check the positive reactionwas calceinwhich was based onobservation ofyellow (green) in colour at the absence (presence) of UV light in infected samples and clear colour in negative control. Detection limits in pure cultures and infected potato extract were also determined. In conventional fliC-PCR, the detection limit rangedapproximately from 10 3 to 10 4cfu ml−1in both infected potato extract and pure cultures. Moreover, the lowest amount of consistently tested positive through LAMP assay was 10 4cfu ml−1 for both cases.
    Although the sensitivity of the fliC LAMP assay wasequal or lower than that of the conventional PCR, the accuracy of fliC LAMP seems to be sufficient toreliably confirmthe presence of R. solanacearum in potato samples. In addition, LAMP protocol assay is time-consuming procedure, does not require expensive equipments, provides visually detection of positive reactions and can apply to survey possible infection in host plants.
    Conclusion
    Consequently, LAMP assay with ashort nucleic acid extraction step like as boiling treatment and efficient visualization processes such as calcein provide suitable preliminary data for screening of pathogen–free tubers prior to storage and during transportation.
    Keywords: Cost-effective method, Entry points, Latent infection, Potato brown rot, Store
  • E. Elahifard, A. Derakhshan, H. Zarrinjoob Pages 284-295
    Introduction
    Since the first compilation of herbicide-resistant weeds in 1982, the number of reported herbicide-resistant species has increased significantly. Iudosulfuron-methyl-sodium mesosulfuron-methyl mefenpyr diethyl, sulfosulfuron and tribenuron-methyl, acetolactate synthase (ALS) inhibiting herbicides, clodinafoppropargyl, aryloxyphenoxypropionate (ACCase) inhibiting herbicides and 2,4-D〣, synthetic auxcins herbicides are registered in Iran for post emergence control of broadleaf and some grass weeds in wheat (Triticumaestivum L.). In southwest Iran, Khouzestan province, the appearance of wild oat (AvenaludovicianaDurieu), littleseedcanarygrass (Phalaris minor Retz) and wild mustard (SinapisarvensisL.) populations with different degrees of resistance to mentioned herbicides has been reported previously in last decade. A reliable seedling bioassay was developed and tested for the rapid screening for resistance to aryloxyphenoxypropionic (APP) herbicides in some.populationsspecialy grass weed. This paper describes a rapid and reliable seedling test to detect APP-resistant A. ludoviciana,Phalaris minor and Sinapisarvensisbiotypes in order to determine their frequency within a population. This test has also been developed in order to discriminate between APP, ALS and synthetic auxcin -resistant biotypes.
    Materials And Methods
    Suspected resistant and susceptible seeds of wild oat, littleseedcanarygrass and wild mustard to iodosulfuron-methyl -sodium mesosulfuron-methyl mefenpyr diethyl, sulfosulfuron and tribenuron-methyl, clodinafoppropargyl and 2,4-D〣 were collected from wheat fields, Shoushtar, southwestern of Iran in 2014 – 2015 growing season. The wild oat and littleseedcanarygrass seedspregerminated in petri dishes. Single doses of clodinafop (1.25 and 0.080 mg ai L-1) were used for the R- and S- populations of wild oat and littleseedcanarygrass, respectively. These experiments were carried out by placing 5 pre-germinated seeds in a 7-cm-diam petri dish containing one piece of filter paper and 5 ml of distilled water or solutions having concentration of clodinafop. The petri dishes were placed in the germinator. The coleoptiles length of seedlings was measured 7 days after treatment (DAT). The pregerminated seeds of wild mustard were sown in pots and irrigated regularly to avoid any moisture stress. Ten days after planting (DAP), they were thinned to two seedlings per pot. Twenty days after weed emergence, seedlings of the pots were subjected to iodosulfuron-methyl-sodium mesosulfuron-methyl mefenpyr diethyl (18 g ai ha-1), sulfosulfuron (19.95 g ai ha-1) and tribenuron-methyl (15 g ai ha-1) and 2,4-D〣 (200 g ai ha-1) application. The sprayer was calibrated to deliver 338 L ha-1 at pressure of 2 atm. The aboveground biomass was harvested 28 days after treatment (DAT) and weighed. Then, distribution map of resistant and susceptible populations in fields was drawn using GIS 9.3 software.
    Results And Discussion
    The results showed that eleven, eight, two and one wild mustard populations were confirmed resistant (RRR), probably resistant (RR), possibly resistant (R?) and susceptible (S) to sulfosulfuron based on “R” ratings system. In addition, three, twelve, three and four wild mustard populations were confirmed resistant, probably resistant, possibly resistant and susceptible to iodosulfuron-methyl-sodium mesosulfuron-methyl mefenpyr diethyl. For tribenuron-methyl, seven, twele and three populations were confirmed resistant, probably resistant, possibly resistant and other populations were susceptible. Meanwhile, whole populations were susceptible to 2,4-D MCPA. Seven days after clodinafop treatment, a clear difference in symptoms was observed between the R- and S- populations. Clodinafop affected the cleoptile length of S- and R-populations of wild oat and littleseedcanarygrass differentially. As, thirty three, fifteen and one wild oat populations were confirmed resistant, probably resistant, possibly resistant and other populations were susceptible. Finally, eight, five and three littleseedcanarygrass populations were confirmed resistant, probably resistant, possibly resistant and other populations were susceptible. Distibution map of populations showed that confirmed, probably, possibly resistant populations were dispersed as uniformaly in the region. As shown in the map, distribution of populations was in the center of region.
    Conclusions
    The results obviously demonstrated that R- and S-populations could be discriminated by the pregerminated seed, whole plant assays. It could be concluded that 2,4-D〣, iodosulfuron-methyl-sodium mesosulfuron-methyl mefenpyr diethyl were more potent than other AlS herbicide group for wild mustard control. Moreover, awareness of distribution map of resistant and susceptible populations could help for better management and prevention the further spread of the populations. We believe that more populations must be studied to determine exact distribution of resistant and susceptible populations in southwest Iran. Finally, extensionists based on distibution maps of resistant populations could recommend herbicides that prevent or delay herbicide resistance development.
    Keywords: Discriminating, recommended dose, Global positioning system, Screening
  • Z. Vakili-Zarj, K. Rahnama, S. Narollah-Nejad, A. Yamchi Pages 296-311
    Introduction
    Canola is one of the important oil crops in Iran and blackleg disease caused by Leptosphaeriamaculans is an economically important disease of rapeseed especially in the northern provinces of Iran. At the beginning of the season in early autumn, L. maculansareinitiatesby air-borne ascospores released from infected stubbles of previous crops. These ascospores germinate and produce leaf lesions. The fungus then grows systemically from the leaf lesions to stem where cankers are producedwhich can result in major yield loss. Blacklegiscaused by a complex of at least two species of Leptosphaeria: L. maculans and L. biglobosa. Of these two species whichL. maculanswasis much more prevalent and virulent than L. biglobosa and was reported from almost all oilseed rape growing regions of the world.A number ofmethods has been developed to differentiate isolates of thesetwo groupsthrough morphological, physiological, genetic and molecular markers. Among these virulence markers of group pathogenicity are most widely used for characterizing the pathogen population. The purpose of this research work was to investigate isolates identification based on colony morphology and molecular methods. Moreover, for management strategies to be effectiveit is important to recognize the population structure based on pathogenicity groups and an understanding of possible shift in fungus population in thenorth of Iran.
    Materials And Methods
    Infected plants of oilseed rape were collected from the northeast Iranduring 2013-2016. Diseased plant organs with clearly defined symptoms of the disease were used for the isolation of the fungi. All isolates were analyzed using a combination of morphological and physiological. In order to confirm the identification of L. maculans from oilseed rape isolates, DNA was prepared using the standard method described previously. The ITS region of genome of all isolates was amplified using polymerase chain reaction with specific primers pair LmF, lmR. Some isolates were sequenced with ITS1 and ITS2 along with the 5.8S rRNAregion and then sequence data were compared with that of available L. maculans isolates in Gene Bank. Aggressive isolates of L. maculans collected in widely separated geographic regions were further divided into pathogenicity groups based on virulence of three differentBrassica napuscultivars.
    Results And Discussion
    Morphological and physiological and molecular characterizations of 72 isolates were performed. Isolates grewslowly, the pycnidia of the fungus were black, globose to subglobose in shape and conidia were single-celled, hyaline. The most of isolates formed yellow and pigment formation was scored in six groups in PDB at 18°C in the dark on the shaker. The PCR detection showed that all isolates were amplified by L. maculans-specific primer pair and a 334-bp PCR product was reliably amplified from L. maculans. The sequence analysis of the ITS region revealed that the sequences had 99.7% sequence similarity with the ITS sequences of known L. maculansisolates in GenBank by NCBI Blast search. This isolates were registered with accession number KX649997 and KX792142 in gene bank and this confirmed that the pathogen exists in Brassica napus samples. The role of morphological identification in virulence is complex and the production of pigment and mycelial growth is not always correlated with virulence. Therefore, based on amplification with type specific primers the amplified product fragment specific for group A was found in all isolates. It is important to know which pathotype is present, because the pathotypes of L. maculans differ in the amount of damage they cause. Based on the reaction of isolates on differential cultivars all four group pathogenicity PG-2, PG-3, PG-4 and PGT were observed in aggressive isolates. The most isolates were classified to be a pathogenicity PG-4 virulent on three differentcultivars and for the first time wasidentified in Iran.
    Conclusions
    In order to determine whether isolates belonging to the canker L. maculans are present in the north of Iran, initial species identification based on colony morphology was confirmed using molecular methods. Asthe pathogen causes considerable losses, thefast identification and pathotype determination are important for agriculture and successful management of blackleg disease. Our results showed that an understanding of possible shift in fungus populations of PG2 to PG4 will be of value in developing strategies for successful management of blackleg disease.
    Keywords: Blackleg stem canker, Morphological, Pathogenicity groups, Specific primers
  • Kh. Abbasi, D. Zafari Pages 312-321
    Introduction
    Potato (Solanumtuberosum) is one of the most important crops used as a source of human food. Iran is the third-largest producer of potato in Asia, where the production rate in 2015 was estimated to be about 5 million tonnes. Potato producers inHamedan province produce 21.3% oftotal potato harvestedinIran. Golden potato cyst nematode, Globoderarostochiensis is the most destructive potato pathogen. As the chitin is a dominant composition in middle layer of the eggshell, using the chitinases produced as chitin-degrading enzymes in a wide range of fungiis a good strategy for biological control of the golden potato cyst nematode. We assessedthe ability of various antagonistic fungi to control Globoderarostochiensisunder in vitro and greenhouse conditions.
    Materials And Methods
    Thirty four fungal isolates obtained from infected eggs of the potato cyst nematode, Globoderarostochiensisin potato fieldsofHamedan were evaluated in two chitin-agar and water-agar mediums under in vitro and greenhouse conditions.The ability of thechitinase enzyme production was assessedin chitin-agar medium with colloidal chitin as substrate, so the chitin was used as exclusive source of carbon.Colloidal chitin was prepared based onthe procedure of Seyedasliet al. (2004) with 10 g of powder chitin from practical-grade crab shell chitin (Sigma) in 100 ml of 85% H3PO4. Water was added to the above mixtureand was filtered with cheese cloth. To completely remove acid, water addition and filtrationrepeated for several times. The produced unguent materialwas dried and powdered and then used as carbon source in the medium. 0.5 percent of colloidal chitin was added to the medium. Afterwards, a 5 mm disk from the edges of 5days old was placed in the center of Petridish and all of them were kept for 5 days at 25º C. Chitinase detection medium (chitin-agar) was directly supplemented with colloidal chitin (5 g/l) and bromocresol purple (0.15 g/l). The ability of antagonistic activity of the fungi on the cyst nematode was testedin water-agar medium through assessing the interaction between fungi and cysts. The numbers of healthy and parasitized (dead) larvae and eggs were calculated after two weeks. The ability of the antagonistic fungi under greenhouse conditions was also analyzed. To provide fungal inoculum, 20g of soaked wheat seed were cast in nylon with autoclave capability. 2 ml distilled water were added per gram of cast seed and they were autoclaved threetimesduring 24 hours. Four fungi disk with 5 mm diameter from selected isolates were then added to allnylonswiththreerepetitions and werekept in 25ºC and dark conditions. To colonizeall of the seeds and avoid hangingthem, the seeds in nylons were mixed within 48 hours interval. After three weeks all of the seeds were infected with fungal isolates. The ability of the antagonistic fungi under greenhouse conditions was studiedby adding fungal inoculum and 100 cysts to each pot and performance evaluation of potato traits in pot after 90 days.
    ANOVA (Analysis of variance) data analysis was conducted using of the SAS software version 9.0 in completely randomized design (CRD) with three replicates under all conditions.
    Results And Discussion
    The ANOVA results ofqualitative evaluation for chitinase activity in Petri dish containing chitin-agar showed significant difference among isolates at1% level of significance. Furthermore, there was apositiveassociationbetween diameter and chitanase activity. Isolates 153(P. lilacinus) and 6 (C. parapsilosis) had the maximum and minimumdiameter, respectively.
    A significant difference was foundamong isolatesin the 0.1% level of significance. Isolate 152 (L. muscarium) had the greatestantagonistic ability and 62 (F. solani)was the weakest antagonist isolate.
    Mean comparisons of measured performance traits of potato in pot showed in all traits thatisolates 154 (T. atroviridae)and 151 (B. bassiana)were the best antagonist isolates under greenhouse conditions. Isolates56 (F. equiseti)and 12 (F. oxysporum)with the lowest measured values in all functional traits were alsothe weakest antagonist fungi.
    Conclusions
    The results illustrated a strong correlation between antagonistic ability of fungal isolates under in vitro and greenhouse conditions.Therefore, fungal isolates can effectively reduce the nematode damages. Finally, isolates 151(B. bassiana), 152(L. muscarium), 153 (P. lilacinus) and 154(T. atroviridae) were selected as the strongest antagonistic fungi in controlling this nematode.
    Keywords: Biological control, Chitin-agar, Parasitism, Yield traits
  • R. Khakzad, M. T. Alebrahim, A. Tobeh, M. Oviesi, R. Valiolahpor Pages 322-336
    Introduction
    Summer annual weeds typically germinate in spring and early summer, grow throughout the summer, and set seeds by fall. Summer annual weeds are a persistent problem in summer annual row crops, competing directly for water, light, and nutrients, causing yield losses in quantity and quality.
    Although agriculture is increasingly relying on modern technology, knowledge of the biological systems in which these technologies are used is still critical for implementation of management strategies. Biological information about weeds is valuable and necessary for developing management strategies to minimize their impact. Scouting fields for pest problems are essential in any cropping system and knowledge of the timing and sequence of weed species emergence could increase the effectiveness of weed scouting trips and subsequent management practices.
    The success of any annual plant is directly correlated to its time of seedling emergence because it determines the ability of a plant to compete with its neighbors, survive biotic and abiotic stresses, and reproduce. The period and pattern of emergence of the weed community depend on the species present in the seed bank and their interaction with the environment. Therefore, knowledge of the weed species present in the soil seed bank and when these species are most likely to emerge is important in planning effective weed control programs.
    Temperature has been reported to be the main environmental factor regulating germination and emergence of weed species. Scientists have developed TT models to predict the emergence of weed species based on a daily accumulation of heat units or growing degree days (GDD) above a minimum base threshold value (Tbase). The predictive models for weed emergence based on the accumulation of TT appear to be accurate enough for projections of weed emergence time (Grundy 2003). Moreover, soil temperature data are easily accessible, making this type of model practical and useful to farmers. Many studies of weed growth, and thus predicting models for areas outside of Mazandaran is performed as a particular study. Because the differences in soil conditions, climatic, geographic and weed species there is a possibility that these models are not appropriate to predict weed species in Mazandaran province. Furthermore, the purpose of this experiment is investigation growth of weeds and develops an empirical model based on GDD to predicting the growth of several species of summer weeds in soybean.
    Materials And Methods
    The experiment was conducted as split split-plot in a randomized complete block design with three replications in the summer of 2016 in Dasht-e-Naz Company Sari-Iran with geographical coordinates 36º 39´ N 53º 11´ E, and 1 meters above sea level. The treatments included two tillage system (No Tillage, Tillage), three densities of 20, 30 and 40 plants per square meter of soybeans and Pursuit-doses (imazethapyr) (0, 50%, 75%, standard dose and 25% of the standard dose, respectively).
    To predict the growth pattern in each plot a fixed 50 × 50 cm quadrat fixed in the center of each plot and since the beginning of the season and after the first irrigation, counting of new grown seedlings was began based on weeds species. The Counting was performed weekly and then counted seedlings were eliminated after in any stage as long as new emergence was not seen.
    Non-linear regression (Sigma Plot 12.5) was used for the expression pattern of cumulative emergence of seedlings. The 3 parameter logistic function was fitted to the data.
    where y represents the predicted cumulative percent emergence, X0, GDD to reach the %50 cumulative emergence, a is the upper asymptote (theoretical maximum percent emergence), b is the slope of the curve.
    We considered that soil water was not a limiting factor for weed emergence, using soil temperature (growing degree days, GDD) as the only independent variable for predicting cumulative emergence. Thus, GDD were calculated with the soil temperatures by using the formula:where Tmax and Tmin are the daily maximum and minimum temperature, respectively, and Tb is the base temperature. Base temperatures used in the calculations of GDD were: 9.0ºC for A. theophrasti, 12.0ºC for S. halepense, 22.3ºC for A. retroflexus, 8.1ºC for E. maculate, 7.5ºC for P. oleracea, 4.0ºC for B. napus.
    From the emergence count data, mean emergence time (MET) and emergence rate index (ERI) were calculated as follows:where N1, ..., Nn is the number of newly emerged seedlings since the time of the previous count, t1, ..., tn are the GDD after sowing, and n is the number of sampling occasions. These two indices give us a simple indication of the emergence process, providing a useful tool to compare the progress of seedling emergence of each species in the two sites. However, they cannot provide more detailed information on emergence duration and speed.
    Results And Discussion
    The results showed that except sorghum that in tillage treatment had the lowest cumulative emergence, other species in no-tillage treatment had the lowest cumulative emergence. At the end of the sampling patterns of emergence has been specified, all species of weeds, in the density of 40 plants per square meter of soybean and dose of 1.25 liter per hectare of herbicide Pursuit had the lowest cumulative emergence and in the density of 20 plants per square meter of soybean and dose of 0 liters per hectare of herbicide Pursuit had the maximum cumulative emergence. Among other species, Amaranthus retroflexus needed the lowest mean emergence time (MET) and the lowest growing degree days (GDD) to reach 50% emergence. Whereas, among the species, Abutilon theophrasti needed maximum mean emergence time (MET) and maximum growing degree days (GDD) to reach 50% emergence. On this basis, growth stage suitable for controlling pigweed, when the main wave of seedlings of other species still have not found growing. The best management practice used to manage weeds will depend upon the weed species present in the soil seed bank, and diversity of management tactics (e.g., planting dates) will result in fewer shifts in species composition.
    Keywords: Emergence pattern, Tillage, Planting density, Herbicide dose
  • M. Latifian, Gh. Kajbafvala Pages 337-351
    Introduction
    The spider mite, Oligonychus afrasiaticus feeds by sucking the sap from the immature fruits tissue. The natural color of fruits changes to pale yellow or gray by mite's feeding. Damaged fruit are cracked and its damage can dry out the fruits. Because of resistance to pesticides, resurgence of date palm spider mite causes to disrupt the natural balance of their population. Tiny black ladybird beetle, Stethorous gilvifrons is the most important and active lady beetle species in Khuzestan province and is very effective on biological control of the spider mite. Determination of the amount and release time of the lady beetles are the most important factors in the implementation of biological control programs of date palm spider mite. So, careful monitoring, time of the release and the ability of deployment of predatory ladybird are essential steps to success in the programs of biological control.
    Materials And Methods
    This research was conducted in Shadegan region of Khuzestan province. The nested design was used to compare the efficiency of different inoculate release methods of the predator, S. gilvifrons. The main niches include three release times which were at the time of emergence, three days and one week after emergence of date palm spider mite in date palm plantation. Sub nesting including three different levels of predator release including minimum, moderate and maximum release with 0.5, 1 and 3 predator /m2 per day and were continued for two weeks. The two or three-days ladybirds were used to release. First, the infected clusters were covered by mesh fabric and ladybirds were released under them. After a week, mantles were opened up to the establishment of ladybird run on the normal condition of date palm plantations. This experiment was repeated three times, and each replication consists of a quarter- hectare plantation with dominant cultivar Sayer.Three date Palm trees from each release and control were randomly selected. One hundred fruits from10 major's of each bunches were randomly selected and the number of spider mite (prey) and coccinellid (predator) were counted in different developmental stages. The relationship between predator and prey was calculated by using Pearson's correlation in different treatments as an index of density-dependent reaction of the predator to prey density and its establishment.
    Results And Discussion
    Results showed that there were significant difference between treatments of release on seasonal mite and lady beetle populations and the average seasonal growth reduction rate at 1% probability level. The maximum difference in the number of mite – infested treatment and control occurred at maximum release with predatory mite. The maximum density of the lady beetle population was observed around mid to late June. Date palm fruits were been at Kharg phonological growth at this time and they had the greatest sensitivity to the mite population. The highest correlation coefficient occurred in terms of release time coincided with the moderate and maximum release of spider mite´s predator. So, the predator showed density - depend reaction and its establishment were occurred. Release of three and one lady beetle/m2 and simultaneously with the appearance of spider mite had powerful and significant correlation. In those circumstances, the density-dependent response of lady beetle was observed. The prey and the predator population densities have several fluctuations around their equilibrium level during the season. Number of predator population declines and prey population increases from their equilibrium levels were reduced by the simultaneous release of the predator to start prey activities. The predatory failure establishment is zero in the maximum release.The highest control of date palm spider mite was about 83.28% at release treatments. In all releasing treatments, the level of biological control was increased with increasing the number of coccinelid releases per unit.
    Conclusions
    The highest predator efficiency were calculated in the maximum release (3 coccinellid per square meter) and simultaneously with the appearance of spider mite in date palm plantation. The control performance was 83.27 percent in this condition. Understanding of the fluctuations of the date palm pests and their natural enemies and the effect of climatic factors on the fluctuations are necessary to operate the proposed models for biological date palm pest control. The success of this predator is high in terms of the date ecosystem, and the susceptibility of palm fruit to pests decreased at the end of the season.
    Keywords: Biological control, Timing of pest release, Predatory lady beetle, Date palm spider mite
  • Z. Saeidi, F. Nourizadeh, H. Gajarieh Pages 352-355
    Introduction
    Cabbage aphid (Brevicorynebrassicae L.) is one of the most important pests of canola in Iran. The pest attacks to the leaves, stems, flowers and pods of the host plant. Feeding and sucking the sap from the plant tissues normally cause leaf and stem deformities and reduce the quality and quantity of the seeds. It was reported that damage caused by the pest can reduce 9 to 77% of the canola yield. Several studies indicated that host plant resistance is an important method which influences population dynamics of B. brassicae and reduces damage of the pest in the field conditions.Using resistant varieties can be the simplest, practical, effective and economical method for the pest control ascomparedwith other control methods. The aim of this investigation was to study population dynamics of the cabbage aphid on different canola cultivars under the natural field infestation and evaluate thepest influence on the studied cultivars/hybrids yield and yield components in Shahre-kord.
    Material and
    Methods
    Population dynamics and damage of cabbage aphid were studied on five cultivars (including: Okapi, Licord, Talaye, Modena, Tasilo) and two hybrids (Hyola 308 and Hyola 401) of canola based on the completely randomized block design in three replicates under the field conditions. To study population dynamics of the pest, sampling was started from the beginning of the infestation (the first decade of April) and continued weekly until harvesting time. For this purpose, five plants in each replicates were selected randomly and the number of aphids (nymphs and adults) was counted on 10 cm of each stem. Moreover, at the harvesting time, 10 plants from each replicate were selected randomly and the yield and yield components includingnumber of pods, number of seed per pods, weight of 1000 seeds were measured. Statistical analysis was done using Proc ANOVA in SAS 9.1 software.
    Results And Discussion
    Ourstudy addressed the seasonal activity and population dynamics of the canola aphid on different canola varieties under the field conditions.The results indicated that the activity of cabbage aphidwas started from the first decade of April and reached to the highest level at the flowering stage at the third decade of May. The highest (450 aphids/plant) and lowest (200 aphids/plant) population density were observed on Talaye cultivar and Hyola 401 hybrid, respectively. Similar results were reported by KhazduziNejadJamali et al. (2012) and Sarwar et al (2002).Mean comparison of yield and yield components in different canola cultivars and hybrids under the field infestation to cabbage aphid showed the highest (83.47) and lowest (12.69) number of pods in Hyola308 hybrid and Modena cultivar, respectively. Moreover, the highest (13.27) number of seeds per pod was observed in Tasilo cultivars, whereasthe highest seed weight was identifiedin Tasilo and Hyola hybrids. Themaximum and minimumyieldwere, respectively, recorded forTasilocultivar(0.41 gr/plant) and Modenacultivar(0.01 gr/plant).Our finding was similar to the results of Monfared et al (2003) who reported that Hyola 308 and Hyola 401 hybrids and Talaye and Licord varieties were resistant to the cabbage aphid. Keyhanian et al (2008) observed the highest pest population on Licord cultivar which supports our findings. However, they reported the lowest yield in Hyola401 which is in contrast with our results. The differences between the results canbe due to the influence of environmental factors on the studied cultivars.
    Conclusion
    Our results demonstrated that Hyola 401 hybrid had the highest number of pods per plantand number of seed per pod and Tasilo cultivar had the highest yield and seed weight. In addition, the lowest yield and yield components was found for Modena cultivar. Therefore, Tasilo was the most suitable and Modena was the least suitable cultivar for growingin Shahre-kord.Sincepesticide applicationto control the pest has several disadvantages such as increasing production cost, developing resistant races, destroying natural enemies and environmental hazards,integrated pest management based on the host plant resistance is, therefore, essential for controlling the canola aphid. Usingthe resistant hybrids and cultivars can reduce insecticides hazards, protect natural enemies and help integrated management of the canola aphid.
    Keywords: Plant resistance, Population dynamics, Waxyaphid, Yield
  • A. Aliverdi, E. Izadi-Darbandi Pages 356-361
    Introduction
    An adjuvant has been defined as ‘a material that when added to a spray solution improves or modifies the performance of an herbicide’. There are five categories of adjuvants including drift retardants, extenders, stickers, wetters, and penetrants. The latter can chemically be divided into mineral or vegetable groups. Although some reports have found that vegetable oils are less effective than mineral oils, in view of the environmental concerns, the use of vegetable oils seem to be a suitable alternative to mineral oils because they offer a series of advantages such as being biodegradable and renewable resources. The plants essential oils are extracted from the medicinal plants not only have an adjuvancy activity at low concentrations but also have an herbicidal activity at high concentrations. It is believed that the benefit of vegetable oils as adjuvant can be related to their ability (i) to increase the drying period of the spray droplets during their fly time before impacting the leaves, (ii) to prevent bouncing off after impacting the leaves, (iii) to decrease contact angle of the droplet on the leaf surface and improve the spreading of them on the leaf surface, (iv) to delay crystallization of the active ingredient on the leaf surface, (v) to reduce the volatizing and photo-decomposing period of the herbicide active ingredient, (vi) to act as a penetrant agent on the leaf epicuticular wax in order to enhance the penetrability of the herbicide active ingredient into the plants. A fundamental part of all agrochemical researches is search to detect the natural chemicals offering adjuvancy properties to enhance the biological activity of agrochemicals. Therefore, we conducted a dose-response experiment to determine the potential influence of Blackseed, Fennel, Olibanum, and Rose oils as oily based-adjuvants in enhancing the imazethapyr activity against jimsonweed.
    Materials And Methods
    The jimsonweed seeds were collected from plants in the fields of Qazvin and were stored in the dark at room temperature until further use. Bioassays were conducted in a greenhouse located on the Ferdowsi University of Mashhad, Iran. The seeds were washed every 1 h for 7 days for a total of 168 washings to remove seed germination inhibitors according to Andersen. They were sterilized with 5% (v/v) sodium hypochlorite solution for 10 min and rinsed with distillated water twice. Then, 25 jimsonweed seeds were sown in 2 L plastic pots filled with a mixture of sand, clay loam soil, and peat (1:1:1). The pots were irrigated three times a week. At the 1- and 2-leaf stage, the seedlings were thinned to 4 plants pot-1 and fertilized twice with 20 mL of a N:P:K (20:20:20) fertilizer with a concentration of 3% (w/v). The pots were irrigated every three days with tap water. Treatments were sprayed at the 4-leaf stage. Experimental design was a factorial arrangement with the 5 doses of imazethapyr (Pursuit® 10% SL) and the four essential oils at concentrations of 0.5 and 1% (v/v) in a completely randomized design with four replications. The emulsifier alkylarylpolyglycol ether was used to emulsify the substances in spray solution (95% oil 5% emulsifier). Treatments were applied at 180 L ha-1 at 200 kPa using a calibrated moving boom sprayer with an 8002 flat-fan nozzle. Three weeks after spraying, biomass from each pot was collected and then weighted after oven-drying at 75°C for 48 h. The data were subjected to a non-linear regression analysis using the following logarithmic logistic dose-response model described. The relative potency that is the horizontal displacement between the two curves was calculated by the ratio of doses producing the same response.
    Results And Discussion
    The slope of dose-response curves for jimsonweed to imazethapyr without or with each adjuvant were significantly similar as indicated by the same slope (b), so that they could be considered to be parallel. This indicates that the adjuvants were biologically inactive if they are used alone (without herbicide) at the tested concentration. Based on shoot fresh and dry weights of jimsonweed, the values of ED10 (6.47 and 7.50 g a.i. ha-1), ED50 (18.08 and 19.01 g a.i. ha-1), and ED90 (50.48 and 43.54 g a.i. ha-1) were obtained. All these values decreased in the presence of all the adjuvants. The relative potency values were significantly different from 1, indicating a significant enhancement in the imazethapyr activity when the adjuvants were added to the spray solution. Based on fresh weight of jimsonweed, the imazethapyr activity was improved up to 4.61-fold with addition of Fennel oil at 1% (v/v). Nonetheless, based on fresh weight of jimsonweed, it was improved up to 4.50-fold with addition of Olibanum at 1% (v/v). Based on dry weight of jimsonweed, the adjuvants were ranked according to their performance in improving imazethapyr activity as follows: Fennel > Olibanum > Blackseed > Rose when they were applied at 0.5% (v/v). But, at 1% (v/v), they were ranked as follows: Olibanum > Blackseed > Rose > Fennel. There are no reports available about the effect of the tested adjuvants as an adjuvant for herbicide, but similar studies were reported by Cabanne who found that the clodinafop-propargyl activity was enhanced up to 5- to 6-fold with adding pine essential oil (Pinus pinaster Ait.) to spray solution at 0.5% (v/v). Vegetable oils have also been found to be effective adjuvants for several post-emergence herbicides. Only in case of Blackseed oil, increasing the concentration had a significant effect to enhance the imazethapyr activity as compared to others. The benefit of concentration effect has formerly observed by researchers who reported that there was a strong concentration effect for rapeseed oil since their influence on phenmedipham and glyphosate uptake and activity was lower at 0.1% than at 1% (v/v).
    Conclusion
    Since the main barrier for diffusing a hydrophilic herbicide such as imazethapyr into the leaf tissue is hydrophobic cuticle, thus oil based-adjuvants have been known to work best with them. On the other hand, a shift from non-environmentally friendly adjuvants to environmentally friendly (namely from mineral oil-based adjuvants to vegetable oil-based adjuvants) in adjuvant trend has been occurred due to being biodegradable and renewable. Thus, it is necessary to look for new essential oils offering adjuvancy properties to improve the efficacy of such foliar-applied herbicides because it is a straightforward approach to reduce the risk of adverse side-effects of herbicide via reducing herbicide dose needed to control suitable weeds. From the present study, it could be concluded that the oils Blackseed, Fennel, Olibanum, and Rose showed a strong adjuvancy properties for imazethapyr against jimsonweed and hence they could be suitable for developing and testing as an oily based-adjuvant. Though it is questioned whether crop selectivity could be threatened when these adjuvants are applied, further work is required under field conditions to answer this question.
    Keywords: Adjuvant, Efficacy, Essential oil, Herbicide