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مطالعات حفاظت گیاهان - سال سی‌ام شماره 3 (پاییز 1395)
  • سال سی‌ام شماره 3 (پاییز 1395)
  • تاریخ انتشار: 1395/09/28
  • تعداد عناوین: 20
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  • علمی - پژوهشی
  • سمانه سمیعی شیرکده، مرتضی گل محمدی، سیدعلی الهی نیا، سمانه بشیری صفحات 359-367
    بیماری بلاست یکی از بیماری های شایع در مناطق گرمسیری و نیمه گرمسیری کشت مرکبات از جمله شمال ایران می باشد که عمدتا به-وسیله جدایه های باکتری (Pss) Pseudomonas syringae pv. syringae ایجاد می شود. به منظور بررسی فنوتیپی و ژنوتیپی جدایه های Pss عامل بیماری، نمونه برداری از درختان مرکبات در غرب مازندران و شرق گیلان طی ماه های اسفند 1390 تا اوایل خرداد 1391 صورت گرفت. جدایه ها از نظر خصوصیات فنوتیپی، بیماری زایی مورد بررسی قرار گرفتند که تعداد 27 جدایه باکتری از بافت های آلوده بر اساس آزمون های فنوتیپی و بیماری زایی به عنوان Pss شناسایی و جدا شدند. جهت تایید شناسایی جنس و گونه باکتری از روش مولکولی (PCR) با استفاده از جفت آغازگرهای اختصاصی باکتری مربوط به ژن اختصاصی تولید سیرینگومایسن استفاده گردید. تمامی جدایه ها با جفت آغازگر اختصاصی قطعه قابل انتظار 198 جفت بازی از ژن syrB را تولید کردند. انگشت نگاری ژنومی جدایه ها به روش rep-PCRبا استفاده از آغازگرهای ERIC و REP انجام شد. نتایج به دست آمده از دندروگرام تلفیق نقوش الکتروفورز حاصل از آغازگرهای ERIC و REP نشان داد که جدایه ها در سطح تشابه 75 درصد در 6 گروه قرار گرفتند. علی رغم وجود خصوصیات فنوتیپی مشابه، نتایج بیانگر وجود ناهمگونی از نظر ژنتیکی در بین جدایه های Pss، عامل بلاست مرکبات در غرب مازندران و شرق گیلان می باشد.
    کلیدواژگان: انگشت نگاری، تنوع ژنتیکی، Pss، rep، PCR
  • ابراهیم ممنوعی، محمدرضا کرمی نژاد، محمدحسن راشد محصل، پرویز شیمی، احمد آئین صفحات 368-378
    به منظور ارزیابی اثر علف کش ها در کنترل علف های هرز مزارع سیب زمینی دو منطقه جیرفت و کرج، آزمایشی به صورت طرح بلوک های کامل تصادفی با چهار تکرار اجرا گردید. تیمارهای آزمایش عبارت بودند از پاراکوات سه لیتر در هکتار، متری بوزین 750 گرم در هکتار، پندی متالین سه لیتر در هکتار، ریم سولفورون 60 گرم در هکتار به همراه 5/2 درصد سیتوگیت، سولفوسولفورون 35 گرم در هکتار، متری بوزین 750 گرم بعلاوه ریم سولفورون 60 گرم در هکتار بعلاوه 5/2 درصد سیتوگیت، متری بوزین 750 گرم بعلاوه پندی متالین سه لیتر در هکتار، متری بوزین 750 گرم بعلاوه سولفوسولفورون 35 گرم در هکتار، پاراکوات سه لیتر بعلاوه ریم سولفورون 60 گرم در هکتار بعلاوه 5/2 درصد سیتوگیت، پاراکوات سه لیتر بعلاوه پندی متالین سه لیتر در هکتار، پاراکوات سه لیتر بعلاوه سولفوسولفورون 35 گرم در هکتار، شاهد وجین در طول فصل رشد. بر اساس نتایج آزمایش تیماری های کاربرد علف کش سبب کاهش تراکم و وزن خشک علف های هرز شدند. مطلوب ترین تیمار علف کش برای کنترل علف های هرز و افزایش عملکرد غده سیب زمینی کاربرد علف کش های پاراکوات بعلاوه ریم سولفورون در جیرفت و کرج بود. این تیمار توانست وزن خشک علف های هرز تاج خروس خوابیده، پیچک و پنیرک را به ترتیب 69، 35 و 56 درصد در جیرفت، و وزن خشک علف های هرز تاج خروس ریشه قرمز، تاتوره و دیوکنف نیز به ترتیب 98، 100 و 100 درصد در کرج کاهش دهد. همچنین با کاربرد تیمار علف کش های پاراکوات بعلاوه ریم سولفورون عملکرد سیب زمینی 31 و 36 درصد به ترتیب در جیرفت و کرج افزایش یافت.
    کلیدواژگان: پنیرک، پیچک، تاتوره، تاج خروس، علف کش
  • مجید جیریایی، هادی اسلامی، علی رستمی صفحات 379-387
    به منظور بررسی تاثیر مایکوریزا و آزوسپیریلوم در میزان مقاومت به بیماری زنگ زرد در ارقام گندم پژوهشی در سال زراعی 1392-1391 در مزرعه تحقیقاتی دانشگاه شهید چمران اهواز اجرا شد. طرح آزمایشی به صورت فاکتوریل در قالب بلوک کامل تصادفی و در 3 تکرار بود. عوامل آزمایش شامل قارچ مایکوریزا در سه سطح (عدم کاربرد، استفاده از گونهGlomus intraradices و G. mosseae)، باکتری lipoferum Azospirillum در دو سطح (عدم تلقیح و تلقیح بذور با قارچ) و ارقام گندم در سه سطح شامل رقم چمران، ارقام دوروم دنا و بهرنگ بود. در این آزمایش شدت آلودگی، میانگین ضریب آلودگی، تیپ آلودگی و سطح زیر منحنی پیشرفت بیماری (AUDPC) زنگ مورد ارزیابی قرار گرفت. یادداشت برداری از شدت و تیپ آلودگی در مرحله برگ پرچم با مقیاس اصلاح شده کب صورت گرفت. اولین علائم ظهور زنگ زرد در محل اجرای آزمایش در نیمه بهمن ماه سال 91 مشاهده شد. نتایج تجزیه واریانس نشان داد که تلقیح بذور با آزوسپیریلوم صفات اندازه‎گیری شده را بین 10 تا 13 درصد کاهش داد. استفاده از مایکوریزا شدت آلودگی را 45-51 درصد، میانگین ضریب آلودگی و (AUDPC) را 74-85 درصد به ترتیب برای گونه های G. intraradices و G. mosseae نسبت به تیمار کنترل کاهش داد. رقم چمران بین 40-70 درصد از ارقام دوروم حساسیت بیشتری به بیماری نشان داد. به طور کلی کمترین شدت آلودگی (33/18) از تیمار تلقیح بذور رقم دنا با آزوسپیریلوم و استفاده از گونه G. mosseae به دست آمد.
    کلیدواژگان: باکتری، برگ پرچم، رقم دنا، شدت آلودگی، قارچ
  • سیما سهرابی، محمدحسن راشد محصل، جاوید قرخلو صفحات 388-395
    فیکاریا گیاهی چندساله از تیره آلاله4 که دارای غده‎های ریشه‎ای5 است. به منظور بررسی ویژگی های مرفولوژیکی و بیولوژی ریشه های غده ای و بذور آن دو آزمایش در آزمایشگاه دانشکده کشاورزی دانشگاه فردوسی مشهد در سال 1391 اجرا شد. برای رفع خواب ریشه های غده ای، آنها در دماهای (2، 4 و 8 درجه سانتی گراد) و زمان نگهداری (7، 14، 21 و 28 روز) در انکوباتور قرار گرفتند. برای بررسی جوانه زنی اندازه و شکل غده ها، شش اندازه (شامل بسیار کوچک (2 تا 4 میلی متر یا کمتر از 02/0 گرم)، کوچک (5/4 تا 5/6 میلی متر یا 04/0-03/0 گرم)، کشیده(1 تا4 سانتی متر یا 27/0-1/0 گرم)، متوسط (8 تا 12 میلی متر یا 12/0-06/0 گرم)، دسته‭ای (64/0-15/0 گرم) و نصف‭شده (7 تا 11 میلی متر یا 18/0-07/0 گرم)) از ریشه های غده ای فیکاریا در دمای 14 درجه سانتی گراد قرار گرفتند. مرفولوژی ریشه های غده ای فیکاریا با مشاهدات چشمی در گلخانه و مزارع آلوده بررسی شد. بذور فیکاریا بعد از قرار گرفتن در یخچال به مدت 2 هفته، جوانه زنی آنها در دمای 14 درجه سانتی گراد و همچنین با بینی کولر ساختار مرفولوژی آن مورد بررسی قرار گرفت. نتایج نشان داد که بهترین تیمار پیش سرمایی دمای 4 درجه سانتی گراد به مدت بیش از 14 روز بود. بین دمای 4 و 8 درجه سانتی گراد تفاوتی وجود نداشت. در بررسی اندازه غده‎ها، غده‎های دسته‎ای و کوچک بیشترین درصد جوانه زنی بیش از 80 درصد را داشتند. در حالی که غده‎های خیلی کوچک، کشیده و نصف شده کمترین درصد جوانه زنی کمتر از 40 درصد را داشتند. غده‎های دسته‎ای با داشتن ذخیره غذایی بالاتر بیشترین سرعت جوانه زنی را داشتند. ریشه های غده ای در ابتدا مجتمع و انگشت مانند بودند، اما اندازه آنها متفاوت بود؛ این غده ها پس از خشک شدن گیاه مادری و به هم خوردن خاک به واحدهای جدا تقسیم شده و هر یک قادر به ایجاد یک گیاه جدید بودند. بذور فیکاریا دارای موسیلاژ بوده و لپه دوم گیاه بنظر تحلیل رفته می آمد. بذور این علف هرز فاقد جوانه زنی بودند (صفر درصد) که دلیل آن هم می تواند به عقیم بودن بذرها ربط داشته باشد.
    کلیدواژگان: اندازه غده، پیش سرمایی، لپه تحلیل رفته، موسیلاژ
  • جواد حمزه ئی، امین بوربور، مجید بابایی صفحات 396-406
    به منظور بررسی اثر سیستم های مختلف خاک ورزی و گیاهان پوششی بر کنترل علف های هرز و عملکرد ذرت آزمایشی به صورت اسپلیت پلات در قالب طرح بلوک های کامل تصادفی در سال زراعی 90-1389 با سه تکرار در مزرعه تحقیقاتی دانشگاه بوعلی سینا اجرا شد. خاک ورزی با گاوآهن برگردان دار، خاک ورزی با چیزل و بدون خاک ورزی در کرت های اصلی و گیاه پوششی ماشک گل خوشه ای، گیاه پوششی خلر، کنترل شیمیایی علف-هرز و تیمار آلوده به علف هرز (شاهد) در کرت های فرعی قرار گرفتند. اثر روش های خاک ورزی و کنترل علف هرز بر کلیه صفات به جز تعداد دانه در ردیف معنی دار شد. اثر متقابل روش های خاک ورزی و کنترل علف هرز نیز بر تعداد ردیف دانه در بلال و عملکرد دانه تاثیر معنی دار داشت. بیشترین عملکرد دانه (1271 گرم در متر مربع) از ترکیب تیماری گیاه پوششی ماشک گل خوشه ایو خاک ورزی با گاوآهن برگردان دار به دست آمد که با ترکیبات تیماری گیاهان پوششی و خاک ورزی با چیزل اختلاف معنی دار نداشت. کمترین عملکرد دانه با 45 درصد کاهش نسبت به تیمار ماشک گل خوشه ایو خاک ورزی مرسوم از تیمار آلوده به علف هرز و بدون خاک ورزی حاصل شد. همچنین، اثر روش های خاک ورزی و کنترل علف هرز و اثر متقابل آن ها در سطح احتمال یک درصد بر تراکم و بیوماس علف های هرز معنی دار شد. بیشترین تراکم و بیوماس علف هرز (به ترتیب 60 بوته در متر مربع و 335 گرم در متر مربع) به ترکیب تیماری آلوده به علف هرز و بدون خاک ورزی تعلق گرفت. کمترین تراکم و بیوماس علف هرز به ترتیب با 62 و 53 درصد کاهش از ترکیب تیماری گیاه پوششی خلر و خاک ورزی حداقل حاصل شد. به طور کلی، استفاده از ماشک و خلر به عنوان گیاه پوششی و خاک ورزی حداقل توانست علف های هرز ذرت را حدود 50 تا 60 درصد مهار کرده و عملکرد آن را افزایش دهد و این امر گامی موثر در جهت نیل به سمت کشاورزی پایدار می باشد.
    کلیدواژگان: خاک ورزی حفاظتی، علف هرز، کشاورزی پایدار، گیاه پوششی
  • محمدحسن بشارت نژاد، هادی استوان، محمدرضا نعمت اللهی، غلام رضا رجبی صفحات 407-415
    شب‏پره فری (Lepidoptera، Cossidae) (Zeuzera pyrina (L. یکی از آفات مهم چوب‏خوار است که گردو از مهم ترین میزبان های آن می باشد. عوامل مختلف روی میزان شکار تله های فرومونی تاثیر می گذارند. در این تحقیق طی آزمایش های جداگانه، تاثیر چهار عامل (نوع فرومون، شکل، رنگ و ارتفاع نصب تله) روی میزان شکار حشرات کامل افراد نر شب‏پره فری در باغ های گردوی منطقه نجف آباد (استان اصفهان) مورد ارزیابی قرار گرفت. نتایج نشان داد که میزان شکار نرها در تله‏های حاوی فرومون پروانه زنبور مانند انگور فرنگی به طور معنی‏داری بیشتر از تله‏های حاوی فرومون شب‏پره فری بود. در مقایسه شکل تله‏ها (استوانه ای، دلتا، بالدار و قیفی) بیشترین شکار به طور معنی‏دار متعلق به تله قیفی بود. در آزمایش6 رنگ با تله دلتا، رنگ‏های سبز و زرد به ترتیب حداکثر و حداقل میزان شکار را داشتند. در حالی که در آزمایش 4 رنگ با تله استوانه ای، رنگ خاکستری معمولی حداکثر و رنگ زرد حداقل میانگین شکار را داشتند. بررسی تاثیر ارتفاع نصب تله (3 ارتفاع مختلف) با دو نوع تله دلتا و بالدار نشان داد که حداکثر شکار در ارتفاع نصب بیش از شش متر از سطح زمین به ‏دست آمد. تحقیق حاضر نشان داد که عوامل مختلف از جمله نوع فرومون، شکل تله، رنگ تله و ارتفاع نصب تله روی میزان شکار نر شب‏پره فری و در نتیجه کارایی تله‏های فرومونی موثر می باشد.
    کلیدواژگان: ارتفاع نصب تله، رنگ تله، شکل تله، نوع فرومون، Zeuzera pyrina
  • مریم غلامشاهی، علی قنبری، مهری صفاری، ابراهیم ایزدی دربندی، مریم سمائی صفحات 416-425
    به منظور بررسی تاثیرات کود نیتروژن همراه با مدیریت علف های هرز بر عملکرد و اجزای عملکرد ذرت رقم سینگل کراس 704 و رشد و سرعت سبز شدن علف های هرز آن آزمایشی در سال 1391 در ایستگاه مرکز تحقیقات و منابع طبیعی استان کرمان در قالب طرح بلوک های کامل تصادفی در سه تکرار اجرا شد. تیمارهای آزمایش شامل مقادیر مختلف نیتروژن در چهار سطح (صفر، 80، 160، 240 کیلوگرم در هکتار)کود اوره (46% نیتروژن) بود. همچنین برای ارزیابی اثر تیمارهای آزمایشی، هر کرت به دو قسمت عاری از علف هرز و آلوده به جمعیت طبیعی علف هرز تقسیم شد. نتایج این آزمایش نشان داد کاربرد نیتروژن همراه با کنترل علف های هرز باعث افزایش معنی داری (01/0P≤) در عملکرد و اجزای عملکرد و سایر صفات رشدی ذرت شد. بالاترین عملکرد ذرت با 82/88 درصد افزایش نسبت به شاهد به میزان 8/12 کیلوگرم در متر مربع در سطح 240 کیلوگرم نیتروژن مشاهده شد. همچنین با افزایش مقدار نیتروژن سرعت سبزشدن و وزن خشک علف های هرز افزایش یافت. علف های هرز چهارکربنه مانند سوروف (Echinochloa crus-galli L. ) دم روباهی (Setaria viridis L.) و تاج خروس (Amaranthus retroflexus L.) نسبت به گونه های سه کربنه افزایش رشد بیشتری نشان دادند. بنابراین در این زمینه گونه های چهار کربنه از نظر رقابتی جلوتر از گونه های سه کربنه قرار می گیرند. از این رو بایستی برای کنترل چنین علف های هرزی در مقادیر بالاتر نیتروژن کنترل آنها در الویت قرار گیرد.
    کلیدواژگان: رقابت، سطح برگ، صفات رشدی، کنترل علف هرز، وزن خشک
  • الهام صمدی کلخوران، محمد تقی آل ابراهیم صفحات 426-440
    به منظور بررسی تاثیر علف کش اگزادیارژیل (Top star 30% EC) به صورت پس رویشی در کنترل علف های هرز مزارع سیب زمینی، آزمایشی مزرعه ای در ایستگاه تحقیقات کشاورزی و منابع طبیعی آلاروق اردبیل در سال 1392 انجام شد. آزمایش به صورت فاکتوریل با تیمار شاهد در قالب طرح بلوک های کامل تصادفی با سه تکرار، دو فاکتور و با استفاده از رقم سیب زمینی مرسوم منطقه (آگریا) انجام شد. فاکتور اول، دزهای علف کش اگزادیارژیل در شش سطح 05/0، 1/0، 2/0، 4/0، 6/0 و 8/0 لیتر ماده موثره در هکتار و فاکتور دوم، زمان های مصرف علف کش در مراحل مختلف رشدی سیب زمینی که در سه مرحله سبزشدن سیب زمینی، استولون زایی و حجیم شدن غده انجام شد؛ همچنین دو تیمار بدون وجین (با علف هرز) و وجین کامل (بدون علف هرز)، به عنوان شاهد در نظر گرفته شد. تجزیه های آماری نشان داد که دزهای اگزادیارژیل و زمان مصرف آن تاثیر معنی-داری بر زیست توده تاج خروس ریشه قرمز (L. Amaranthus retroflexus)، تاج خروس خوابیده (Amaranthus blitoides S. Watson.)، کل علف-های هرز و عملکرد کل غده داشت ولی اثرات متقابل آن معنی دار نشد. نتایج نشان داد که کاربرد دز 8/0 لیتر ماده موثره در هکتار، زیست توده تاج-خروس ریشه قرمز، تاج خروس خوابیده و کل علف های هرز را توانست به ترتیب 58/80، 74/81 و 16/66 درصد نسبت به شاهد با علف هرز کاهش دهد. اثرات متقابل دزهای اگزادیارژیل و زمان مصرف آن نشان داد که بالاترین درصد کاهش زیست توده سلمه تره (Chenopodium album L.) در دز 8/0 لیتر ماده موثره در هکتار مرحله سبز شدن سیب زمینی می باشد. در بین زمان های مصرف اگزادیارژیل در مراحل مختلف رشدی سیب زمینی، مرحله سبز شدن سیب زمینی، زیست توده تاج خروس ریشه قرمز و کل علف های هرز را به ترتیب 01/60، 51/44 درصد کاهش داد ولی زیست توده تاج خروس خوابیده در مرحله حجیم شدن غده، بالاترین درصد کاهش (49/67 درصد) را حاصل کرد. کاربرد اگزادیارژیل به میزان 8/0 لیتر ماده موثره در هکتار در مرحله سبز شدن سیب زمینی، بالاترین عملکرد کل غده در هکتار را ایجاد کرد.
    کلیدواژگان: دز پاسخ، زیست توده علف های هرز، عملکرد غده سیب زمینی، کنترل علف های هرز
  • فریبا نیک رفتار، پریسا طاهری، سعید طریقی صفحات 441-448
    به منظور بررسی امکان القای مقاومت در گیاه گوجه فرنگی رقم حساس موبیل علیه قارچ Rhizoctonia solani، از ویتامین ها و هموسرین لاکتون ها استفاده شد. تیمار تیامین 20 میلی مولار بهترین تاثیر را در القای مقاومت علیه این بیمارگر داشت. جهت بررسی نقش پراکسیداز در مقاومت القایی ناشی از تیامین، از سدیم آزید به عنوان بازدارنده پراکسیداز استفاده شد و در زمان های 0، 24، 48 و 72 ساعت بعد از مایه زنی قارچ، میزان ترکیبات فنلی در نمونه های تیمار شده و شاهد اندازه گیری شد. بین محتوای فنل کل در نمونه های مختلف و زمان های متفاوت مورد بررسی، تفاوت قابل توجهی مشاهده شد. در نمونه های تیمار شده با سدیم آزید میزان ترکیبات فنلی نسبت به دیگر نمونه ها کمتر بود. جلوگیری از فعالیت این آنزیم منجر به کاهش تولید ترکیبات فنلی و کاهش میزان مقاومت به بیمارگر در برگ های تیمار شده با تیامین و سدیم آزید گردید. بر اساس نتایج این تحقیق، پراکسیداز و ترکیبات فنلی نقش مهمی در مقاومت القایی ناشی از تیامین در گوجه فرنگی علیه R. solani ایفا می کنند.
    کلیدواژگان: القای مقاومت، پراکسیداز، گوجه فرنگی، محتوای فنل کل، ویتامین B1
  • مجتبی اسمعیلی، علیرضا بندانی، قدرت الله صباحی صفحات 449-459
    مینوز گوجه فرنگی Tuta absoluta Meyrick (Lep.: Gelechiidae) از مهم ترین آفات این محصول در جهان محسوب می شود که در سال های اخیر به کشور وارد شده است. هدف این مطالعه تعیین اثر عصاره های پروتئینی استخراجی از دانه های 12 گیاه بر فعالیت پروتئاز گوارشی این حشره است. در این مطالعه اسیدیته بهینه فعالیت پروتئازی و تاثیر اسیدیته بر فعالیت مهارکنندگی عصاره ها نیز تعیین گردید. این بررسی نشان داد که ترکیبات استخراج شده از دانه گیاهان نخود، کلزا و دو رقم گندم (البرز و افلاک) به ترتیب با 57، 53، 51 و 50% مهارکنندگی اثر چشمگیری بر فعالیت پروتئاز لارو مینوز گوجه فرنگی دارند. همچنین مهارکننده های استخراج شده از تریتیکاله، رقم سیوند گندم و باقلا به ترتیب با 44، 43 و 40% مهارکنندگی نیز توانایی خوبی در مهار پروتئاز مینوز گوجه فرنگی نشان دادند. اما مهارکننده های داتوره، لوبیا و یولاف وحشی به ترتیب با 26، 25 و 24% مهارکنندگی نسبت به سایر مهارکننده ها تاثیر کمتری روی پروتئاز لاروی نشان دادند. این مطالعه همچنین نشان داد که بیشینه فعالیت پروتئازی در آفت مذکور در اسیدیته 10 و دمای 40 درجه سلسیوس صورت می گیرد. از طرفی بیشترین مهارکنندگی حاصله از دانه های نخود، کلزا و دو رقم گندم البرز و افلاک در اسیدیته های قلیایی انجام شد. با توجه به قلیایی بودن اسیدیته معده آفت، و اینکه بیشترین فعالیت آنزیم نیز در اسیدیته قلیایی است می توان نتیجه گرفت که این مهارکننده ها قادرند در شرایط طبیعی (In vivo) در مهار پروتئاز آفت موثر واقع شوند هر چند برای تحقق این امر انجام آزمایش های تکمیلی ضروری خواهد بود.
    کلیدواژگان: پروتئاز، عصاره های پروتئینی، مهارکنندگی، مینوز گوجه فرنگی
  • اکبر بخشانی، عصمت مهدیخانی مقدم، ساره بقایی راوری صفحات 460-467
    به منظور شناسایی نماتدهای انگل گیاهی مزارع پنبه در استان خراسان جنوبی، در سال های 1392 و 1393، تعداد 56 نمونه خاک از مناطق مختلف استان جمع آوری گردید. شستشوی خاک و استخراج نماتدها با استفاده از روش تلفیق الک و سانتریفیوژ جن کینز (1964) و سینی وایت هد (1965) و تثبیت و انتقال آن ها به گلیسرین طبق روش دگریس (1969) انجام گرفت. سپس از نماتدهای استخراج شده به تفکیک جنس، اسلایدهای میکروسکوپی تهیه و با استفاده از میکروسکوپ نوری مورد مطالعه قرار گرفت. پس از بررسی های میکروسکوپی، اندازه گیری های لازم و رسم تصاویر مورد نیاز، شناسایی گونه ها با استفاده از منابع و کلیدهای معتبر انجام گرفت و تعداد 15 گونه نماتد متعلق به 10 جنس شناسایی گردید که عبارتند از:Aphelenchus avenae، Basiria graminophila، Boleodorus clavicaudatus، B. pakistanensis، B. thylactus، Ditylenchus hexaglyphus، D. tenuidens، D. valveus، Geocenamus rugosus، Filenchus vulgaris، Pratylenchus thornei، P. neglectus، Scutylenchus quadrifer، Merlinius brevidens،Zygotylenchus guevarai.
    از بین جنس و گونه های شناسایی شده، سه گونه Boleodorus pakistanensis، Ditylenchus hexaglyphus و D. valveus برای اولین بار از ایران گزارش و توصیف می شوند.
    کلیدواژگان: تاکسونومی، نماتد، Boleodorus pakistanensis، Ditylenchus hexaglyphus، D. valveus
  • امیرحسین ناظمی، قربانعلی اسدی، رضا قربانی صفحات 468-480
    تاثیر مقادیر مختلف عصاره اسطوخودوس شامل صفر (شاهد)، 4، 20، 40، 100، 200، 300 و 400 قسمت در میلیون عصاره (پی پی ام) بر روی جوانه زنی بذور علف های هرز تاج خروس ریشه قرمز، سلمه تره، سوروف، خرفه و قیاق و گیاه زراعی ذرت به صورت 6 آزمایش جداگانه در قالب طرح کاملا تصادفی مورد ارزیابی قرار گرفت. غلظت کومارین موجود در عصاره معادل 245 پی پی ام عصاره تهیه شده بود. با وجود تفاوت های بین گیاهان مورد مطالعه، نتایج نشان دهنده سمیت بالای عصاره اسطوخودوس برای گیاهان بود. تمامی مولفه های جوانه زنی به طور معنی داری در تمامی گیاهان تحت تاثیر قرار گرفت. به طور کلی، افزایش غلظت عصاره اسطوخودوس موجب افزایش اثرات دگرآسیبی آن شد و باعث شد که درصد جوانه-زنی، سرعت جوانه زنی، طول ریشه چه و ساقه چه و وزن خشک گیاهچه کاسته شود. غلظت های پایین کاربرد عصاره موجبات بروز اثرات تحریک کنندگی بر جوانه زنی بذر خرفه، سوروف، قیاق و ذرت شد. خرفه حساسیت نسبی بالاتری به عصاره اسطوخودوس از خود نشان داد. در حالی که ذرت تحمل نسبی بالاتری به عصاره اسطوخودوس از خود نشان داد.
    کلیدواژگان: ذرت، علف های هرز، کومارین
  • نوید ناصریان، حسین فرازمند، آرمان آوندفقیه، رضا وفایی شوشتری صفحات 481-487
    کرم گلوگاه انار، Ectomyelois ceratoniae Zeller (Lep.: Pyralidae)، مهمترین آفت باغ های انار در ایران است و تله های فرمونی یکی از ابزارهای مطمئن برای پایش جمعیت آن به شمار می روند. در این پژوهش، تاثیر عواملی مانند ارتفاع تله، نوع تله، رنگ تله، جهت نصب تله، دز پاسخ، دوام فرمون و میزبان گیاهی بر میزان شکار یک نوع تله‏ی فرمونی در قالب یک طرح بلوک کامل تصادفی با 4 تکرار، در استان لرستان مورد بررسی قرار گرفت. نتایج نشان دادند که تله دلتا، بهترین شکل تله با شکار روزانه 38/0 عدد شب پره نر بود. مقایسه ارتفاع تله‏ها نیز حاکی از مناسب تر بودن ارتفاع 5/1 متری بود، به طوری که این ارتفاع دارای بیشترین میانگین شکار روزانه (20/0 عدد شب پره نر) بود. بررسی رنگ و جهت نصب تله‏های فرمونی نشان داد که رنگ سفید، مناسب ترین رنگ و جهت جنوبی درختان، بهترین سمت نصب تله‏ها می باشد، به طوری که میانگین میزان شکار روزانه تله‏های سفید 28/0 عدد شب پره نر و میانگین شکار روزانه تله های نصب شده در جهت جنوبی درختان 25/0 عدد شب پره نر به دست آمد. با توجه به اطلاعات به دست آمده، مناسب ترین شرایط نصب تله های فرمونی سنتتیک کرم گلوگاه انار، تله‏های سفیدرنگ نوع دلتا و در ارتفاع 5/1 متری و روی پایه‏ چوبی می باشد. مناسب ترین تعداد پخش کننده شبه فرمون، دو عدد و بهترین دوره‏ی زمانی تعویض پخش کننده شبه-فرمون، دو هفته به دست آمد. این اطلاعات می توانند در پایش جمعیت کرم گلوگاه انار مورد استفاده قرار گیرند.
    کلیدواژگان: آفات انار، تله فرمونی، فرمون جنسی، ردیابی
  • مهدی نصراصفهانی صفحات 488-493
    جهت بررسی امکان کنترل نماتد سیستی چغندر قند (Heterodera schachtii Schmidt) در مزارع آلوده آزمایش هایی با استفاده از روش‏های آفتاب‏دهی و استفاده از کود حیوانی نپوسیده در مزارع آلوده اطراف کارخانه قند اصفهان در منطقه جی و قهاب صورت پذیرفت. چهار تیمار این آزمایش شامل، استفاده از روش آفتاب دهی خاک با به کارگیری ورقه های پلاستیکی شفاف، استفاده از کود حیوانی تازه، تلفیق پوشش ورقه های پلاستیکی و کود حیوانی و شاهد بدون انجام هیچ گونه عملیات در سه تکرار در قالب طرح بلوک‏های کامل تصادفی بود که در زمینی آلوده به نماتد مذکور طی دو سال انجام گردید. داده‏های مربوط به جمعیت نهایی تعداد سیست‏های پر و تعداد تخم و لارو سن دوم موجود در هر سیست و در هر گرم خاک مبنای تجزیه و تحلیل آماری قرار گرفت. فاکتور تولید مثل و درصد کاهش و یا افزایش جمعیت نماتود سیستی چغندرقند، در هر تیمار نسبت به جمعیت اولیه‏ی همان تیمار در سال‏های اول، دوم و میانگین آنها در مجموع دو سال آزمایش محاسبه گردید. نتایج نشان داد تیمار تلفیق کود حیوانی و آفتاب دهی در سال اول، دوم و در مجموع دو سال بیشترین اثر را در کاهش جمعیت نهایی نماتد سیستی چغندرقند نسبت به سایر تیمارها و شاهد داشته است. تیمارهای کود حیوانی و آفتاب دهی به تنهایی از لحاظ آماری تفاوتی با یکدیگر نداشتند و هر دو با هم در یک گروه آماری نسبت به تیمار تلفیق کود حیوانی و آفتاب دهی و نیز شاهد قرار گرفتند. تیمار تلفیق کود حیوانی و آفتاب دهی در سال اول، دوم و میانگین دو سال به ترتیب با 04/0، 003/0 و 021/0 کمترین فاکتور تولیدمثل را داشت. این مقادیر به ترتیب سال‏های ذکر شده با 96، 7/99 و 85/97 درصد کاهش جمعیت نسبت به جمعیت اولیه، بیشترین درصد کاهش جمعیت را نشان می‏دهد. پس از این تیمار نیز تیمار آفتاب‏دهی با فاکتورهای تولید مثل 05/0، 02/0 و035/0 و هم چنین، درصد کاهش جمعیت 95، 98 و 5/96 به ترتیب سال‏های آزمایش بهترین تاثیر را در کاهش جمعیت نماتود سیستی چغندرقند داشت.
    کلیدواژگان: اصفهان، ضد عفونی خاک، کودهای دامی، مبارزه تلفیقی
  • رحمان خاکزاد، رضا ولی الله پور، محمد تقی آل ابراهیم صفحات 494-504
    در مناطق شمالی ایران 35 درصد از اراضی به صورت باتلاقی می باشد و در حال حاضر بدلیل ماندابی بودن، هیچ گونه کشتی غیر از برنج در آن توصیه نمی گردد. با این توصیف جهت بهره وری بیشتر و استفاده مطلوب از منابع موجود در این گونه اراضی پرورش راتون به عنوان یکی از راهکارهای موثر و اساسی در امر تولید و درآمد بیشتر زارعین تلقی می گردد. به همین منظور آزمایشی برای بررسی کارایی علف کش های مختلف بر کنترل علف های هرز و عملکرد برنج راتون به صورت طرح بلوک های کامل تصادفی با 4 تکرار در روستای پاشا کلا شهرستان ساری در سال 1390 انجام شد. تیمارها عبارت بودند از: 1- آنیلوفوس+ اتوکسی سولفورون (3 لیتر در هکتار)، 2- بوتاکلر (3 لیتر در هکتار) + سینوسولفورون (100 گرم در هکتار)، 3- بن سولفورون- متیل (75 گرم در هکتار) + بوتاکلر (3 لیتر در هکتار)، 4- بوتاکلر (3 لیتر در هکتار)، 5- سینوسولفورون (100 گرم در هکتار)، 6- بن سولفورون- متیل (75 گرم در هکتار) به همراه تیمار وجین دو مرحله ای و عدم کنترل علف های هرز. نتایج نشان داد که علف کش-های گروه سولفونیل اوره ها مانند بن سولفورون متیل و سینوسولفورون، تراکم و وزن خشک علف های هرز را به ترتیب 60 و 93 درصد در طول فصل رشد کاهش دادند که این امر منجر به افزایش عملکرد برنج راتون در انتهای فصل رشد شد. همچنین نتایج نشان داد که علف کش بوتاکلر تاثیری بر تراکم و وزن خشک گونه های علف های هرز، تراکم و وزن خشک مجموع علف های هرز نداشت که در نهایت موجب کاهش عملکرد و وزن هزار دانه برنج راتون گردید.
    کلیدواژگان: تراکم علف هرز، علف کش های سولفونیل اوره، مناطق شمالی، وزن خشک علف هرز
  • امیرهوشنگ جلالی، حکمت اسفندیاری صفحات 505-517
    به منظور بررسی روند تغییرات تراکم علف های هرز مزرعه گندم به ویژه جودره، پژوهشی سه ساله (1390 تا 1392) با استفاده از آزمایش کرت-های خرد شده در قالب طرح بلوک های کامل تصادفی با سه تکرار در شهرستان اردستان انجام شد. سامانه های مختلف خاک ورزی شامل خاک ورزی مرسوم (گاو آهن برگردان دار)، خاک ورزی حداقل (کولتیواتور مزرعه) و بدون خاک ورزی فاکتورهای اصلی و شش تناوب مختلف، فاکتورهای فرعی آزمایش را تشکیل دادند. نتایج پژوهش نشان داد در سال زراعی اول، تراکم بوته (متر مربع)، تعداد ساقه و وزن خشک بوته (گرم در هر متر مربع) جودره در سامانه خاک ورزی مرسوم و کشت جو در ابتدای تناوب، به ترتیب برابر 33/5، 33/13 و 33/33 بود که به طور معنی دار (سطح 5%) کمتر از سایر گیاهان ابتدای تناوب و همچنین آیش بود. در سامانه خاک ورزی حداقل و در تناوب (کلزا- ذرت- گندم)، تراکم بوته، تعداد ساقه و وزن خشک جودره به ترتیب برابر با 28 (بوته در متر مربع)، 6/136 (ساقه در متر مربع) و 6/239 (گرم در متر مربع) بود که از نظر آماری نسبت به سایر تناوب ها (به جز تناوب کلزا- آیش- گندم) بیشتر بود. در دومین سال زراعی آزمایش، در سامانه بدون خاک ورزی، دو تناوب (کلزا- آفتابگردان- گندم) و (گندم– آیش- گندم) به ترتیب با 33/11 و 66/13 بوته جودره در متر مربع کمترین مقادیر را نسبت به سایر تناوب ها داشتند. به طور خلاصه استفاده از سامانه خاک ورزی مرسوم و گیاهان هم خانواده غلات (بجز جو) می تواند از عوامل افزایش علف هرز جودره محسوب شود.
    کلیدواژگان: بدون خاک ورزی، بقایا، گاو آهن برگردان دار، گندم
  • ابوالفضل درخشان، محمدرضا مرادی تلاوت، سید عطااله سیادت صفحات 518-532
    جوانه زنی یک جمعیت بذری در پاسخ به کاهش پتانسیل آب با استفاده از مفهوم هیدروتایم مدل سازی می شود. این مدل دارای خروجی هایی است که از نظر فیزیولوژیکی و اکولوژیکی معنی دار می باشند. یکی از پیش فرض های مدل هیدروتایم، توزیع نرمال پتانسیل آب پایه در میان بذرهای یک جمعیت است. با این حال، این فرض در بسیاری از گونه ها مشاهده نمی شود که برآیند آن پیش بینی نادرست جوانه زنی است. در این مقاله مدلی بر مبنای توزیع بتا پیشنهاد می گردد که علاوه بر پیش بینی بسیار مناسب الگوی جوانه زنی از نظر زیست شناختی نیز بر مدل مرسوم برتری دارد. در این پژوهش، جوانه زنی بذر شاه افسر (Melilotus officinalis (L.) Lam.)، خردل وحشی (Sinapis arvensis L.) و جو (Hordeum vulgare L.) در محدوده ای از پتانسیل های آب مورد آزمون قرار گرفت و پاسخ جوانه زنی آنها توسط مدل هیدروتایم مبتنی بر دوازده تابع آماری نرمال، بتا، گاما، لوگ لجستیک، ویبول، گامبل، بیرنبام-ساندرز، نرمال معکوس، لوگ نرمال، لجستیک، ریلی و گاما معکوس توصیف گردید. نتایج نشان داد که پارامترهای برآورد شده با مدل هیدروتایم مبتنی بر توزیع بتا از اطمینان بیشتری نسبت به سایر توزیع ها برخوردار بود (AICc برای شاه افسر، خردل وحشی و جو به ترتیب معادل 60/556-، 70/864- و 20/1034- برآورد شد). بر اساس مدل هیدروتایم بتا، ثابت هیدروتایم و آستانه پتانسیل آب برای شروع جوانه زنی بذر شاه افسر بترتیب 01/14 مگاپاسکال ساعت و 85/0- مگاپاسکال، برای خردل وحشی به ترتیب 33/22 مگاپاسکال ساعت و 98/0- مگاپاسکال و برای جو به ترتیب 69/48 مگاپاسکال ساعت و 47/2- مگاپاسکال برآورد شد. با توجه به انعطاف پذیری توزیع بتا، این مدل امکان پیش بینی دقیق جوانه زنی و نیز تعیین توزیع پتانسیل آب پایه را فراهم می آورد.
    کلیدواژگان: پتانسیل آب پایه، تابع توزیع تجمعی، مدل بتا، مدل سازی
  • مرضیه مظهری، محمودرضا تدین صفحات 533-536
    علف های هرز از طریق هم جواری و رقابت با گیاه زراعی رشد و نمو و عملکرد گیاهان زراعی را کاهش می کنند و خواب بذر مشکلی برای کنترل علف های هرز است. به منظور بررسی اثر تیمارهای مختلف بر شکست خواب و جوانه زنی بذور شنگ و خاکشیر پژوهشی به صورت طرح بلوک های کاملا تصادفی در تیمارهای مکانیکی شکست خواب (استفاده از آب جوش) و آزمایش های فاکتوریل در قالب طرح کاملا تصادفی در سه تکرار در دانشگاه شهرکرد سال 1391 انجام شد. تیمارها شامل سطوح مختلف جیبرلیک اسید (0، 100، 250 و 500 میلی گرم) به شکل خیساندن در دو سطح زمانی 2 و 24 ساعت، نیترات پتاسیم در غلظت های (50، 100 و 150) میلی مولار نیترات پتاسیم در دو سطح زمانی10 و 30 دقیقه، تیمار تناوب دما (15-5 و 20-10 درجه سانتی گراد) در شرایط نور کامل، تاریکی و تناوب نور (8 ساعت روشنایی و 16 ساعت تاریکی) و تیمارهای مکانیکی شکست خواب (آب جوش) بودند. بررسی درصد جوانه زنی نشان داد که در گیاهان شنگ و خاکشیر تیمار تناوب دما و نور بیشترین تاثیر را در شکست خواب بذور داشت و کاربرد جیبرلیک اسید و نیترات پتاسیم تاثیری بر شکست خواب بذور گیاهان شنگ و خاکشیر نداشت. با توجه به شکست خواب بذور شنگ و خاکشیر در تیمارهای تناوب دما و نور می توان نتیجه گرفت که خواب بذور شنگ و خاکشیر از نوع ترکیبی است.
    کلیدواژگان: بذر، تیمار شیمیایی، تناوب دما و نور، علف هرز
  • فاطمه خنده رو، غلامحسین مروج، حسین صادقی نامقی، لیدا فکرت صفحات 537-540
    طی نمونه برداری های انجام شده جهت بررسی فون بند پایان درخت زبان گنجشک در شهرستان مشهد و حومه، در اردیبهشت ماه 1393، تعدادی زنبور پارازیتوئید متعلق به خانواده ی Eulophidae جمع آوری و جهت شناسایی نزد دکتر لطفیه گنسر در دانشگاه کامهاریت ترکیه ارسال که با نام های علمی Aprostocetus catius (Walker، 1839)، Asecodes erxias (Walker، 1848)، Chrysocharis pubicornis (Zetterstedt، 1838)، Neochrysocharis chlorogaster Erdös، 1966 شناسایی گردیدند. این گونه ها برای اولین بار از ایران گزارش شده اند. این خانواده دارای 540 جنس و 3900 گونه در جهان می باشد. تاکنون در ایران از این خانواده، 106 گونه متعلق به 37 جنس در 4 زیر خانواده گزارش شده است.
    کلیدواژگان: زبان گنجشک، زنبور پارازیتوئید، مشهد
  • غلامرضا دره کی، غلامرضا زمانی صفحات 541-546
    به منظور بررسی عوامل موثر در شکستن خواب بذر علف هرز بزدندان (Tragus racemosus L. AlI.)، این آزمایش در قالب طرح کاملا تصادفی با 4 تکرار در آزمایشگاه تحقیقاتی دانشکده کشاورزی دانشگاه بیرجند در سال 1392 انجام شد. تیمارهای مورد آزمایش شامل: شاهد، سرمادهی مرطوب در دمای 4 درجه سانتی گراد، استفاده از اسید سولفوریک غلیظ 97 درصد، نیترات پتاسیم و جیبرلیک اسید بودند. تعداد بذرهای جوانه زده بطور روزانه به مدت 21 روز شمارش و در پایان درصد جوانه زنی و سرعت جوانه زنی محاسبه گردید. نتایج تجزیه واریانس درصد جوانه زنی و سرعت جوانه زنی نشان داد که سطوح مختلف در کلیه تیمارها بر صفات اندازه گیری شده معنی دار بود. بیشترین درصد جوانه زنی در تیمار سرمادهی مرطوب در دمای 4 درجه سانتی گراد به مدت 4 هفته با 76 درصد و کمترین درصد جوانه زنی در شاهد با 6 درصد مشاهده گردید. بیشترین درصد جوانه زنی در تیمار اسیدسولفوریک در سطح 80 ثانیه، 41 درصد، در تیمار نیترات پتاسیم در سطح 8/0 درصد، با 69 درصد و در تیمار جیبرلیک اسید، در سطح ppm400 با 62 درصد بود. بیشترین سرعت جوانه زنی در تیمار استفاده از نیترات پتاسیم (8/0 درصد) با 24/18 بذر در روز و کمترین سرعت جوانه زنی در شاهد با 91/0 بذر در روز مشاهده گردید. همچنین بیشترین سرعت جوانه زنی در تیمار اسیدسولفوریک در سطح 80 ثانیه، با 28/15 بذر در روز، در تیمار سرمادهی مرطوب در سطح 3 هفته با 25/13 بذر در روز و در تیمار جیبرلیک اسید، در سطح ppm200 با 08/12 بذر در روز بود. نتایج این آزمایش نشان داد بهترین روش شکستن خواب بذر علف هرز بزدندان تیمار سرمادهی مرطوب در دمای 4 درجه سانتی گراد است.
    کلیدواژگان: اسیدسولفوریک، جیبرلیک اسید، درصد جوانه زنی، سرمادهی مرطوب، نیترات پتاسیم
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  • S. Sameie, Shirkadeh, Morteza Golmohammadi, S.A. Alahinia, S. Bashiri Pages 359-367
    Introduction
    P. syringae pv. syringae (P.s.s), the causal agent of blast of citrus trees, is one of the most important plant pathogens in the world. P.s.s is unique among most P. syringae pathovars according to its ability to cause disease in over 180 species of plants in several unrelated genera. Traditionally, Strains of P.s.s are identified on the basis of biochemical and nutritional tests and symptom expression in host plants. Genomic fingerprinting methods based on the polymerase chain reaction (PCR) have been applied for identification and classification of plant-associated bacteria to the subspecies level. The objectives of this study were the phenotypic and molecular evaluation of P.s. pv. syringae strains causing citrus blast in the West of Mazandaran and the East of Guilan, and study of genetic diversity of P.s.s isolates of citrus by using ERIC and REP-PCR markers.
    Materials And Methods
    During 2011 to 2012, citrus infected tissues were sampled from different orchards in the West of Mazandaran and the East of Guilan. Bacterial phenotypes were studied based on standard physiological and biochemical tests. Gram reaction was determined by potassium hydroxide solubility test (KOH test). Strains were grown on KingB medium (KB) and fluorescent pigment production was evaluated. Levan formation, oxidase reaction, potato soft rot, Arginine dihydrolase and induction of the hypersensitive reaction in tobacco leaves (LOPAT tests), were done as described by Schadd et al. The standard strains of P.s. pv. syringae form IVIA were used as reference strains in this study. Pathogenicity Test was done as described by Yessad et al. Citrus seedlings were maintained in a greenhouse at 20°C. In addition, a PCR-based method was used to confirm the genus and species of bacteria by using bacterial specific primer pair’s designed for a specific gene of syringomycin B. Genetic diversity among the strains, was studied by rep-PCR fingerprinting. Genomic fingerprinting was carried out according to the methods of rep-PCR with ERIC primers of Little et al. and with REP primers of Zhao et al. The amplified PCR products were analyzed by gel electrophoresis on a gel containing 1.5% agarose in 1 × TAE buffer. Similarity analyses were done with the NTSYSpc ver. 2.02 software (Exeter Software, New York, USA) as described by Rohlf. Similar coefficients were compared using SM coefficient analysis according to the number and position of bands. Dendrograms were produced according to the unweighted pair-group mean arithmetic method (UPGMA) using NTSYSpc software.
    Results And Discussion
    Bacterial strains were identified on the basis of Phenotypic and pathogenicity tests. Twenty- seven isolates of bacteria identified as P. syringae pv. syringae. Strains in which the gram reaction was negative were investigated based on physiological and biochemical characteristics. All P.s.s strains used in this study were negative for oxidase, potato rot, and Arginine dihydrolase but, positive for levan production and the hypersensitive response in tobacco. Strains were positive in gelatin, casein, aesculin, fluorescent pigment production, and tolerant to 5% NaCl, syringomycin production tests, but negative for urease, hydrolysis of starch. Growth at 370C, reduction of nitrate to nitrite and the hydrolysis of tween 80 were variable. These strains produced acid from glucose, xylose, sorbitol, galactose, sucrose and mannitol, but did not produce acid from maltose, Ramnose and the use of lactose were variable. All of the P.s.s strains were pathogenic on seedlings and produced progressive necrotic symptom. To confirm biochemical identification of the bacterial strains, the specific markers were selected for PCR. All 27 isolates of the P.s.s and the standard strains of P.s.s form IVIA produced the expected 198 bp. fragment of the gene syrB with specific markers. The isolates were determinated as P. s. pv. syringae based on phenotypical features and molecular identification. Traditionally, strains of P.s.s are recognized based on biochemical, nutritional, and physiological characteristics of citrus in different parts of Mazandaran. To assess genetic diversity among the strains, ERIC and REP-PCR analysis were used. Strains formed 6 and 5 clusters in the ERIC-PCR and REP-PCR, at 75% similarity level respectively and by the combination data set of both ERIC and REP-PCR, strains formed 6 clusters. In addition, strains formed 2 clusters at 62% similarity level. Cluster one contained the strains of citrus from Kelarabad, Chaboksar, Ketalem. The second Cluster contained other strains with the standard strains of P.s.s (IVIA). Diversity among P.s.s strains using rep-PCR fingerprinting was considerable. The results of this study demonstrated that P.s.s strains isolated from citrus trees are genotypically heterogeneous.
    Conclusion
    In Iran, P.s.s strains were isolated from citrus and characterized. They emphasized phenotypic and nutritional. Whereas genotypic features of this pathogen have not been studied yet. In our study, according to phenotypic and molecular methods, strains were identified as P. s. pv. syringae. Despite similar phenotypic characteristics, the results indicated the existence of genetic heterogeneity among Pss strains causing citrus blast in the West of Mazandaran and the East of Guilan. The rep-PCR method is low cost, rapid, and reliable to discriminate plant-pathogenic bacteria at the pathovar level. Similar results have been reported in other studies of the strains isolated from other plants. Disclosing the population diversity of each pathovar, in turn, has implications for the implementation of breeding programs, disease management strategies, and ecological and epidemiological studies.
    Keywords: Fingerprinting, Genetic diversity, Pss, Rep-PCR
  • Ebrahim Mamnoie, Mohammad Reza Karami Nejad, Mohammad Hasan Rashed Mohassel, Parviz Shimi, Ahmad Aeen Pages 368-378
    Introduction
    Potato (Solanum tuberosum) is an annual crop that belongs to the Solanaceae family. It contains abundant starch and ranks as the world’s fourth most important food crop, after maize, wheat and rice. It is one of most important crops in Iran. The total area under potato cultivation was 186 thousand hectares during 2011 and 2012. Weeds are one of the greatest limiting factors to efficient crop production. Application of herbicides is the key method of weed control in potato fields, both in the world and Iran. Herbicides that commonly are used for weed control in potato fields of Iran are metribuzin, paraquat, rimsulfuron, pendimethalin and sulfosulfuron.
    Materials And Methods
    In order to study the effect of herbicides to control weeds of potato fields, field experiments were conducted at the Agricultural Research Center of Jiroft and Karaj. Plots were located on a sandy loam soil with a pH of 7.4 in Jiroft, and loamy soil with a pH of 7.7 in Karaj. The experiments were conducted during 2009-2010. Potato variety used in Jiroft was Santeh and Satina in Karaj. The experimental design was the randomized complete blocks design (RCBD), with four replications. Weed control treatments included paraquat (20% SL) at 3 lit/ha as early post- emergence, metribuzin (70% WP) at 750 gr/ha as preemergence, pendimethalin (33% EC) at 3 lit/ ha as preemergence, rimsulfuron (25% DF) at 60 gr/ha applied with adjuvant cytogate at 2.5% volume of water early post emergence, sulfosulfuron (75% DF) at 35 gr/ha (postemergence), metribuzin at 750 gr/h rimsulfuron at 60 gr/ha with adjuvant cytogate at 2.5% volume of water, , metribuzin at 750 gr/ha pendimethalin at 3 lit/ ha, metribuzin at 750 gr/ha sulfosulfuron at 35 gr/ha, paraquat at 3 lit/ha rimsulfuron at 60 gr/ha with adjuvant cytogate at 2.5% volume of water, paraquat at 3 lit/ha pendimethalin at 3 lit/ha, paraquat at 3 lit/ha sulfosulfuron at 35 gr/ha and hand weeding. Each plot was 4 m wide and 8 m long with 4 rows and 75 cm distance among rows. Density and dry weight of weeds and potato yield were recorded.
    Results And Discussion
    Results indicated that 6 broadleaf weeds were dominant in the fields included prostrate pigweed (Amaranthus blitoides), bindweed (Convolvulus arvensis), malva (Malva neglecta) in Jiroft, and red rooted pigweed (Amaranthus retroflexus), datura (Datura stramonium), bladder hibiscus (Hibiscus trionum) in Karaj. Visual observation confirmed that the most weeds were effectively controlled using herbicide treatments. The statistical analysis of the data revealed that the herbicides applied for weed control in potato have significantly decreased weed density and dry weight. The lowest weed density and dry weightof prostrate pigweed were observed in plots treated with paraquat rimsulfuron. This treatment reduced density and dry weight of prostrate pigweed by 70% and 69% in Jiroft. However, Red rooted pigweed was controlled better than prostrate pigweed in Karaj. All treatments of mixed herbicides reduced density and dry weight of red rooted pigweed by 100% in Karaj. Maximum control of bindweed was obtained with metribuzin rimsulfuron. This treatment reduced density and dry weight of bindweed by 35 % in Jiroft. The highest control of malva was achieved with metribuzin plus rimsulfuron in Jiroft. This treatment reduced density and biomass of malva by 61 and 56%, respectively. The best control of datura was obtained with paraquat plus rimsulfuron in Karaj. This treatment reduced datura biomass by 98%. Maximum control of bladder hibiscus was obtained with paraquat plus rimsulfuronin which dry weight was reduced by 98%. The highest potato yield (48 ton/ha) was obtained by application of metribuzin plus rimsulfuron in Jiroft. Potato yield was also increased with this treatment by 40%. The least potato yield (32 ton/ha) was obtained with pendimethalin in Jiroft. The maximum potato yield (32 ton/ha) was obtained by application of paraquat plus rimsulfuron and paraquat plus pendimethalin in Karaj, and minimum potato yields were obtained by application of sulfosulfuron and pendimethalin.
    Conclusion
    Results of both years and locations showed that application of herbicide mixture improved weed control and potato yields. Pendimethalin and rimsulfuron are suitable alternatives for herbicide rotations in potato fields and can replace metribuzin and paraquat.
    Keywords: Amaranthus spp., Convolvulus arvensis, Datura stramonium, Herbicide, Malva neglecta
  • M. Jiriaie, H. Eslami, A. Rostami Pages 379-387
    Introduction
    Wheat is one of the major agricultural crops with respect to human nutrition. It is cultivated over a wide range of environments, because of wide adaptation to diverse environmental conditions. In Iran, 6.2 million hectares are under wheat cultivation, of which 33% is irrigated and 67% is rain-fed, the irrigated wheat growing areas (2 million hectares) are located mostly in southern, central and east of Iran Production of crops is under the influence of plant genetic structure, environmental conditions and their interactions. Biotic and abiotic stresses are considered to lower production. Among the biotic stress, the fungal disease is the main factor limiting production of crop plants in hot and humid regions. Stripe rust was not a serious economic concern to the wheat industry for most of the 1990’s due to the use of resistant varieties. However, by 2003 it had developed into a significant issue, particularly as new path types evolved. Even in the dry years of 2003 and 2004, stripe rust cost growers significant income. Provide country's need for wheat as a strategic product, meanwhile, production is free from chemical fungicide is a high but achievable goal. So in order to achieve fertilizer and fungicide resources that in addition to having no adverse effects on consumers and the environment, has been economically able to provide nutrition need of crop plant, is very important.
    Materials And Methods
    With this approach, to survey the effect of Mycorrhiza and Azospirillum in resistance to yellow rust in wheat cultivars, an experiment was conducted at the research station of the Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on a randomized complete block design with three replications. The treatments include of Mycorrhiza fungi in three levels (without application of Mycorrhiza strain and using strain Glomus intraradices and Glomus mosseae), Azospirillum lipoferum bacterium in two-levels (non-inoculated seeds and inoculated seed) and wheat cultivars in three levels, Chamran (bread wheat), Dena and Behrang (durum wheat) varieties. In this experiment evaluated, to yellow rust disease, the intensity of infection, the average coefficient of infection, type of infection and area under disease progress curve (AUDPC). Infection type and disease severity were also recorded at flag leaf stage using modified Cobb’s scale. First symptoms of yellow rust were observed in middle January of 2013. Analysis of variance was performed using PROC ANOVA of SAS (version 9.1.3, 2004The comparison of the means was done by Duncan test at a probability level of 5 percent.
    Results And Discussion
    Survey on the resistance to yellow rust in wheat cultivars treated with Mycorrhiza and Azospirillum showed that seed inoculation with Azospirillum traits reduced between 10 percent to 13 percent and the use strains of Mycorrhiza fungi intensity of infection 45-51 percent, the average coefficient of infection and AUDPC 74-85 percent respectively for G. intraradices and G. mosseae strains have been reduced compared with control and Chamran cultivar between 40-70 percent showed more Sensitivity to disease from durum varieties. Generally, the lowest of infection intensity (18.33) was obtained from inoculation of C.V Dena seeds with Azospirillum and G. mosseae strain. According to the result, we found yellow rust in all experiment field also the incidence varied between 10-70 percent. Therefore, it is concluded that, given the climatic conditions favorable to the spread of yellow rust, the incidence of yellow rust in the region that have a high degree of pathogenicity. In general the results of this test, mycorrhiza application has a significant role in enhancing wheat resistance to yellow rust. The seed inoculation with Azospirillum although did not have significant role in disease control, but increased at an acceptable level resistance to wheat rust. But the important point was the combined use of fungi and bacteria the synergistic effect of the two substances for all traits were assessed, leading to an increase of more than 20 percent in the wheat varieties resistant to rust.
    Conclusion
    Generally associated with resistance to yellow rust in wheat cultivars inoculation with A. lipoferum and usage of G. mosseae in Dena cultivar that was durum wheat, showed the highest resistance to yellow rust, probably this has been due to the Dena cultivar which is durum wheat. It seems, use of the biofertilizers can be the perfect solution to eliminate the nutritional requirements of wheat, in addition, it has been an important effect in enhancing resistance to yellow rust.
    Keywords: Bacteria, Dena cultivar, Disease severity, Flag leaf, Fungi
  • S. Sohrabi, M. H. Rashed Mohassel, J. Gherekhloo Pages 388-395
    Introduction
    Ranunculus ficariais L. (Fig buttercup or Lesser Celandine) is an herbaceous perennial belongs to Ranunculaceae (buttercup family) that behaves as a ground cover. It is a spring ephemeral that grows from a cluster of tuberous roots in late winter or early spring. It has glossy, dark green (sometimes slightly mottled), fleshy leaves on long petioles, and cordate to oblong-cordate in shape. The margins can be entire or wavy (1, 28). Flowers 15-60 mm in diameter, solitary at the end of each stem branch. Flowers have 3 sepals (rarely more), 3 petals, bright, pale to golden yellow, very rarely orange, shining on inside, receptacle concave, with short, pale simple glandular hairs. Achenes either abortive or maturing in a globular cluster, when mature 2•5-5•0 x 1•7-3•5 mm, more or less globular or obovoid, usually with few to numerous very short simple glandular hairs. This invasive weed spreads primarily by vegetative means through abundant tubers and bulblets, each of which can grow into a new plant once separated from the parent plant. The prolific tubers may be unearthed and scattered by the digging activities of some animals, including well-meaning human weed pullers, and spread to new sites during flood events (28). This weed has two subspecies, R. ficaria Subsp. ficaria and R. ficaria Subsp. bulbilifer that the second is probably the only subspecies of mountainous regions in many areas. It is an abundant weed of lawns and gardens, where it spreads rapidly and is very difficult to eradicate. According to our observations probably R. ficaria spread by tubers from mountains to fields that near to mountains in Lorestan province of Iran. The Aim of this study was assessment of this weed to improve its management practices in the wheat fields.
    Materials And Methods
    In order to study the some aspects of biology and morphology of tubers root and seeds of R. ficaria , two experiments were conducted at Laboratory of Gorgan University in 2011. For breaking root tubers dormancy, root tubers incubated for different storage time (7, 14, 21 and 28 days) and different storage temperature (2, 4 and 8˚C). To evaluate the effect of tuber size, six groups (very small
    Keywords: Cotyledon, Mucilage, Pre-chilling, Tubers root size
  • Javad Hamzei, Amin Bourbour, Majid Babaei Pages 396-406
    Introduction
    Using cover crops in conservation tillage systems offers many advantages, one of which is weed control through physical and chemical interferences. Most of the benefits of cover crops are well known. They prevent form wind and water erosions, conserve soil moisture by reducing evaporation and increasing infiltration, increase the content of organic matter, increase fertility by recycling nutrients, add nitrogen if they are legumes, and improve soil structure. Proper cover crops can also suppress weed growth by allelopathic activities and light interference. They impact on environmental quality through the protection of surface water and groundwater, as well as eliminating the need for using preemergence herbicides. Either increase or decreases have been reported for crop yields when the crop residues remain on soil surface. No-till system has been reported to increase the presence of certain difficult to control weeds. Therefore, the aim of this study was to investigate the effect of tillage systems and cover crops on weed control and corn yield.
    Materials And Methods
    Experiment was carried out as split plot based on randomized complete block design with three replications at the Bu-Ali Sina University in growing season of 2011. Tillage with moldboard, tillage with chisel (minimum tillage), and no tillage were considered as main plots and two cover crops, winter vetch and chicklingpea, chemical weed control and weed-infest treatment (control) were considered as sub-plots. Cover crops were cultivated in late March 2011. In early June 2011, cover crops were harvested and were spread over the soil surface. The Plot size was 22.50 m-2. Five rows were in each plot with 75 cm intervals among rows and 18 cm among seedlings. 2 square were picked in the three central rows of each plot in order to determine the yield and yield components. From each plot three quadrants (1×1 m)randomly were picked and weeds and cover crops was separated. All samples were dried at 72 ° C for 48 hours and then were weighed. Data were analyzed using SAS software. Wherever the F test showed significant effect for a source of variance, the differences among treatments were compared by LSD test at the 0.05 level of significance.
    Results And Discussion
    Analysis of variance showed that the effects of tillage systems and weed control methods were significant on all traits, except number of seed per ear. Also, the interaction effect of them had significant effect on number of grain row/ear and grain yield. The highest grain yield (1271 g m-2) was observed at combined treatment of winter vetch cover crop and moldboard tillage. This treatment had no significant difference with combined treatments of cover crops and tillage with chisel. In comparison with winter vetch cover crop and conventional tillage treatment, the lowest grain yield by 45% reduction was recorded at weed infested and no tillage treatment. Also, the effects of tillage systems and weed control methods and their interaction were significant on weed density and biomass. Maximum weed density and biomass (60 plant m-2 and 335 g m-2) were belonged to weed-infested treatment under no tillage system. The lowest values for weed density and biomass with reduction of 62 and 53%, respectively, were observed at combined treatment of chicklingpea cover crop and minimum tillage. Chicklingpea and winter vetch cover crops due to rapid establishment and growth capacity are more suitable for weed control. Cover crops can affect weed establishment through effects on the radiation and chemical environment of weed and inhibit weed emergence by physically impeding the progress of seedlings from accessing light as well as by releasing phytotoxins that inhibit seedling growth. Minimum tillage is often cause changes in of weed flora and their population, and this is one of the methods for integrated weed management. In general, using winter vetch and chicklingpea as a cover crop and tillage with chisel suppressed about 50-60% weeds and increase corn yield which is effective step towards achieving sustainable agriculture.
    Keywords: Conservation tillage, Cover crops, Sustainable agriculture, Weeds
  • M.H. Besharatnejad, H. Ostovan, M.R. Nematollahi, Gh. Radjabi Pages 407-415
    Introduction
    The leopard moth, Zeuzera pyrina (L.) (Lepidoptera, Cossidae), is an important xylophagous pest on different trees such as walnut, Juglans regia (L.), which weaken the host trees by canalling in the trunks. Regarding type of damage and host range of the pest, it is so difficult to control. Catching of the male moths by traps containing sex pheromone lures is a promising method to control the pest. There are many factors influencing potential of pheromone traps. Some of these factors, such as trap shape, trap color and height of trap placement, can be manipulated by the user or grower. One of the components of the pheromone blend of leopard moth is (E, Z)-2, 13-octadecadien-1-ol acetate, which seems to be the pheromone compound of the current clearwing moth Synanthedon tipuliformis (Clerck) (Sesiidae).
    Materials And Methods
    Separate experiments were conducted in walnut orchards (each having more than 10 years of damage history and area of 0.5-3.5 ha) of Najaf-Abad County (Isfahan, Iran). Pheromone traps were placed on the trees in late April. The traps were inspected at 5-day intervals until late July. The number of catched lthe moth males was recorded and also, during the growth season average of the capturing per trap per night was calculated. Lures were replaced monthly. In the present study the effects of four factors (pheromone type, trap shape, trap color and height of trap placement) on the number of catched leopard moth males were evaluated. The experiments for different factors were conducted as follows: 1. Pheromone type and lures of pheromones of S. tipuliformis and Z. pyrina, both of which were provided from Agriscense Company, were compared. 2. Trap shape, four shapes (cylindrical or standard, delta, wing and funnel) were compared. The experiment was conducted using white-colored traps placed at the height of 1.5m above the ground and had S. tipuliformis lures. 3. Trap color, three separate experiments were conducted as follows: delta traps with 3 colors (white, yellow and green), delta traps with 6 colors (white, yellow, green, glossy gray, normal gray and red), cylindrical traps with 4 colors (green, yellow, with and normal gray). In the experiments, traps with height of 2m above the ground had S. tipuliformis lures. 4. Height of trap placement, two separate experiments with delta and cylindrical traps were conducted for comparison of three placement heights of 1.5, 3 and more than 6 meters above the ground. The experiment was conducted using white - colored traps which had S. tipuliformis lures. All above experiments were conducted in a randomized complete block design with three or four replications. Analysis of variance was performed after data transformation, using log (x). In all experiments means were compared using Tukey̕s test, except for the experiment of pheromone type, which compared using t-student test.
    Results And Discussion
    In the present study the catching was started on 4th of May and lasted till 26 July. During 105 nights of trapping, traps, which were continuing lures of S. tipuliformis and Z. pyrina, were captured in total 77 and 7 leopard moth males, respectively. Means of capturing per trap per night were 0.18 and 0.01, respectively. Results showed that catching of male moths were significantly higher on traps containing lures of S. tipuliformis than those containing lures of Z. pyrina. In comparison to shape of traps, significantly the highest catches belonged to funnel trap. The superiority of the funnel traps could be related to its specific structure. Comparison of 6 colors with delta traps showed that green and yellow colors had the highest and the lowest catching, respectively. However, in comparison of 4 colors with cylindrical trap, the highest and the lowest catching belonged to normal gray and yellow, respectively. In the present study, ranking of trap colors changed by trap shape. The phenomenon might be related to the interactions between the factors of traps̕ shape and color. In the experiments of height of trap placement, the highest catching was obtained at the height more than 6 m with both delta and wing traps. It shows that the amount of catching is increasing by increasing in the height of trap placement.
    Conclusion
    Pheromone traps could be used as a useful method for catching leopard moths males. However efficacy of the pheromone traps was influenced by several factors, including type of pheromone, trap shape, trap color and height of trap placement.
    Keywords: Height of trap placement, Pheromone type, Trap color, Trap shape, Zeuzera pyrina
  • M. Gholamshahi, A. Ghanbari, M. Saffari, E. Izadi Darbandi, M. Samaie Pages 416-425
    Introduction
    Corn is one of the important crops of poaceae family which has important role in supplying food for human societies. Corn is third food crop in world and it has high potential compare to other crops because of its C4 photosynthetic pathway. In addition, corn is a strong and fast growing plant but it is sensitive to competition with weeds. According studies, there are 25 to 30 problematic weeds in corn farms which they include annual and perennial species. Annual weeds life cycle is similar to corn life cycle, there for the most problem of weeds in corn is summer annual weeds. Damage of weeds is different and it depends on weeds density, species composition, time of emergence, crop variety and other factors. While non control of weeds depending on those density and Variety, corn yeild may be decrease of 15 to 90 percent. Weeds which germinate in a short time can compete with crop on light, water and nutrition sources. Most of the weeds show better reaction to fertilizers compare with crops. This subject is due to weeds ability to nutrition absorption and aggregation and their high performances. Most of the weeds species are more responsive than crops to application of nitrogen fertilizer. Furthermore, the growth of most of the weed species increases with increasing nitrogen. Therefore, the increase of nitrogen in farming systems can have impacts on weeds and crops competitiveness. However, weeds compete with crop about using light, nutrient, water and soil space and the result of this competition is yield losses. Moreover, nitrogen is necessary to increase yield and nitrogen fertilizer enhances corn competitiveness, especially early in the season due to the slow growth of the plant and is necessary to achieve optimal performance. Excessive of nitrogen fertilizer during the growing season is benefit for weeds. Therefore, in order to study the effects of nitrogen fertilizer in combination with weeds management on yield and yield components of corn and weeds growth and emergence, a field study was conducted in research Station of Natural Resources Research Centre, Kerman province.
    Materials And Methods
    This experiment was conducted using a randomized complete block design with three replications. The treatments consisted of different levels of nitrogen in four levels (0, 80, 160, 240 kg ha-1) urea fertilizer (46%). In addition, for assessment the effect of experimental treatments, each plot separated into two parts (complete control and non-control of weeds). Preparing the field was done with autumn plowing and spring disc. Corn seeds (single cross 704) were planted on rows in the spring with hand and with the density of 71000 plants per hectare with row spacing of 70 cm and 20cm. Irrigation was performed on average every7 days. Weeds in the control treatment were weeding by hand twice during the growing season.
    Results And Discussion
    The results showed that nitrogen application in combination with weeds control increased yield and yield components of corn and the other growth traits, significantly. The maximum corn yield observed 12/8 kg under high nitrogen treatment (240 kg ha-1) with 88/82% increase compare with non-fertilizer treatment. Moreover, increase in nitrogen imposed a significant positive affect on height, yield and yield components including (Length and ear diameter and ear dry matter, the number of grains in row and the number of rows in ear, hundred grain weight). Nitrogen is one of the factors affecting the development of leaf area per plant and therefore, the development of the corn canopy. It seems that the increase of nitrogen during the tassel stage and seed formation which are the most sensitive stages to nitrogen absorption and photosynthesis, increased the length of ear. In addition, results of the experiment indicated that control of weeds had significant effect on different growth factors. Furthermore, the increase nitrogen rate caused to weeds emergence rate and dry weight increase. The greatest dry weight of weeds was observed at the highest level of fertilizer (240 kg ha-1). It can be said that in the latter stages of growth that competition was effected and caused dominance strong species, increasing fertilizer after a certain amount (160 kg ha-1) had no effect on the dry matter competing species in the field. Therefore, it seems that competition in the early stages is very important.
    Conclusion
    C4 weeds such as Barnyard grass and Slender foxtail and Redroot pigweed, showed more growth increase compare with C3 species. Therefore, C4 species are more dominance than C3 species in competition and increased germination rate for these weeds with increasing nitrogen rate. As a result, we should control these weeds early in high nitrogen rate. So, nitrogen fertilizer had positive impact at different forms on the plants, resulting in the use of this nutrient should be done more researches.
    Keywords: Competition, Dry matter, Growthtraits, Leaf area, Weed control
  • E. Samadi Kalkhoran, M.T. Alebrahim Pages 426-440
    Introduction
    Potato (Solanum tuberosum L.) is one of the most important root crops in the world. Weed is biotic stress that reduces yield and quality of crops through competition. Chemical weed control seems indispensable and has proved efficient in controlling weeds. Metribuzin and Paraquat are registered herbicides for potato production in Iran which are using early in the growing season. Metribuzin and Paraquat are dual purpose herbicides and destruct photosystem sites of action (Metribuzin is photosystem Ⅱ inhibitor and Paraquat is photosystem Ⅰ inhibitor) which are not control summer weeds. Oxadiargyl belongs to the oxidiazole chemical group and acts as a protoporphyrinogen oxidase inhibitor and primarily has been developed for general weed control in rice and sugar cane. It is commonly used in rice, potato, sunflower, onion, cabbage, chickpea, spanish and lettuce and lavender. Weed control obtained with oxadiargyl at rates above 0.30 kg a.i/ ha was comparable to the standard metribuzin at 1.0 kg a.i/ ha; Oxadiargyl was superior comparing to the standard on Solanum nigrum, a weed of common occurrence in potato plantations, and Panicum subalbidum. The objective of our research was to evaluate the efficacy of Oxadiargyl for weed control and determination of appropriate application time in potato fields.
    Materials And Methods
    Trials were conducted in Ardabil Agriculture and Natural Resources Research Station during 2013. The factorial experiment with control (with and without weeding) was performed based on randomized complete block design with three replications. Potato cultivar was Agria (common cultivar in Ardabil). The first factor was Oxadiargyl dosages with six levels (0.05, 0.1, 0.2, 0.4, 0.6 and 0.8 Lit a.i/ ha), and the second factor was time of application (at different potato growth stages; potato emergence, stoloning and tuber bulking), as well as two treatments (with and without weeding) were considered as control. Tubers were hand sown on 22th May in rows 75 cm apart and 20 cm on the rows at 10 cm depth. Oxadiargyl was applied by backpack sprayer fitted with 8001 flat fan nozzles. Three weeks after treatment, Weed sampling was carried out by a (0.75× 0.50 m2 quadrate). Tubers were harvested from center row to determine total tuber yield per hectare.
    Two three parameter model were fitted to the data including: Three parameter logistic function ( )
    Three parameter sigmoid function ( )
    a: maximum weed biomass and total yield, b: The slope and x0 (ED50): the dose causing 50% reduction in weed biomass.
    Data were statistically analyzed using SAS 9.1 software and MSTAT-C. Analysis of variance was used to test the significance of variance sources, while Duncan’s Multiple range test (P = 0.05) was used to compare the differences among means.
    Results And Discussion
    Results showed that maximum reduction percent for redroot pigweed (Amaranthus retroflexus L.), prostrate pigweed (Amaranthus blitoides S. Watson) and total weed biomass achieved by 0.8 lit a.i/ha application. Interaction between oxadiargyl dose and application time showed maximum reduction percent for common lambsqurter (Chenopodium album L.) at 0.8 lit a.i/ha in potato emergence. Alebrahim et al.(2) reported that application of oxadiargyl as pre and post emergence 160 gr/ha reduced biomass of common lambsquarter by 78 and 87 percent, respectively, and oxadiargyl application pre and post emergence 200 gr/ha educed biomass of common lambsquarter by 84 and 93 percent, respectively. Also oxadiargyl application pre and post emergence 240 gr/ha reduced biomass of common lambsqurter by 87 and 94 percent, respectively. Alebrahim et al. (1) reported application of oxadiargyl post emergence 0.4, 0.5 and 0.6 Lit ai/ ha reduced biomass of common lambsqurter 87.75, 93.25 and 94.75 percent respectively. Alebrahim et al., (3) reported greenhouse application of oxadiargyl post emergence 0.1 and 0.6 Lit ai/ ha reduced biomass of common lambsqurter 70.17 and 100 percent respectively. Alebrahim et al., (2) reported that application of oxadiargyl pre and post emergence at 160 gr/ ha reduced biomass of redroot pigweed 76 and 82 percent respectively and applying 200 gr/ ha pre and post emergence reduced redroot pigweed biomass 79 and 90 percent respectively. and 240 gr/ha reduced redroot pigweed biomass 85 and 95 percent respectively. Alebrahim et al., (1) reported application of oxadiargyl post emergence 0.4, 0.5 and 0.6 Lit a.i/ ha reduced redroot pigweed biomass 82.75, 90.75 and 95 percent respectively. Furthermore greeonhouse application of Oxadiargyl post emergence 0.1 and 0.6 Lit a.i/ha reduced biomass of common lambsqurter 65.92 and 100 percent respectively (3). Barb et al., (7) reported application of oxadiargyl 0.25, 0.30, 0.35, 0.40, 0.45 and 0.50 kg a.i/ ha reduced total weed biomass 73, 77, 77, 82, 82 and 86 percent 5 week after treatment and 74, 73, 80, 80, 83 and 84 percent 8 week after treatment respectively. Among oxadiargyl application time at different potato growth stages, potato emergence reduced redroot pigweed and total weed biomass 60.01 and 44.51 percent respectively as compared to control (weedy); also tuber bulking reduced Prostrate pigweed biomass 67.49 percent as compared to control (weedy). Application of 0.8 Lit a.i/ ha and potato emergence stage produced maximum total tuber yield per hectare. Alebrahim et al., (1) reported potato tuber yield 27.60, 32.30 and 35.3 ton/ha while oxadiargyl applied 0.4, 0.5 and 0.6 Lit a.i/ ha pre emergence and 33.17, 35.93 and 36.85 ton/ha while applied 0.4, 0.5 and 0.6 Lit a.i/ha post emergence.
    Conclusion
    Results showed that maximum reduction percent for redroot pigweed, prostrate pigweed and total weed biomass was achieved by 0.8 lit a.i/ha application. Interaction between herbicide dose and application time showed 0.8 lit a.i/ha at potato emergence reduced common lambsquarter biomass 87.94 percent. Application of oxadiargyl at potato emergence stage reduced redroot pigweed and total weed biomass and increased total tuber yield. However suggested to carry out the experiment over several years, to evaluate potato tolerance of varieties to Oxadiargyl and the effectiveness of other herbicides mixing with Oxadiargyl for future researches.
    Keywords: Dose - response, Potato tuber yield, Weed biomass, Weed control
  • F. Nikraftar, P. Taheri, S. Tarighi Pages 441-448
    Introduction
    Tomato (Solanum lycopersicum) is one of the most important crops worldwide, which suffers from several destructive diseases. Rhizoctonia solani is a necrotrophic fungus which is known as the causal agent of tomato damping-off, seed rot, root and crown rot diseases. Control of this phytopathogenic fungus is very difficult due to its long-term survival in the soil, high level of genetic diversity in R. solani populations and the lake of complete resistance in plants to the pathogen. Although partial genetic resistance to Rhizoctonia diseases has been reported, no major gene responsible for resistance has been found so far. Most of the traditional cultivars, planted in tomato-growing areas, are susceptible to Rhizoctonia diseases. Therefore, an intensive use of other crop protection methods such as an application of chemicals or biological agent which are capable of activating plant defense responses seems to be necessary to suppress the disease damage in tomato fields. The growing concern on negative environmental effects of fungicides and the appearance of fungicide- resistant pathogens led to increased research interest in the alternative protection methods. Among these novel disease management strategies, induced resistance (IR) has emerged as a potential supplement in plant protection trials.
    Materials And Methods
    The cultivar CH Falat was used as a susceptible tomato genotype to R. solani. The seeds were surface sterilized with 1% sodium hypochlorite for 1min, rinsed 3 times with sterile distilled water and incubated for 5 days on a wet sterile filter paper in Petri dishes. Germinated seeds were each sown in plastic pots filled with autoclaved commercial potting soil and kept in greenhouse conditions. The tomato leaves were treated with various concentrations of thiamine, pyridoxine, and homoserine lactones and inoculated with the pathogen. Disease symptoms were evaluated at 5 days post-inoculation (dpi) and the most effective inducer of resistance at the best concentration was selected for the rest of the experiments. The role of phenolic compounds and peroxidase in thiamine-IR was investigated in our pathosystem. For phenolics measurement, leaf and stem samples (500 mg FW) were crushed into fine powder in liquid N2 with a mortar and pestle and were extracted separately in 8 ml of 80% methanol. The extracts were centrifuged at 4000 g for 5 min. To determine the number of total phenols, 50 ml of the extract was placed in microtubes containing 700 ml of distilled water and 50 ml of Folin. After 5 min, 100 ml of 20% sodium carbonate and 100 ml distilled water were added and the tube contents were mixed. Absorbance at 720 nm was determined after 60 min using a spectrophotometer. Total phenol was expressed as the milligrams per gram of tissue fresh weight. Soluble phenolic contents were calculated using a standard curve obtained with different concentrations of caffeic acid. For determining peroxidase activity, enzyme extracts (containing 30 mg of total protein) were added to 30 ml of 200 mM guaiacol and 25mM citrate phosphate (pH 5.4). To each sample, 30 ml of 30% H2O2 was added and the absorbance was measured at 470 nm using a spectrophotometer.
    Results And Discussion
    Disease index evaluations after various treatments revealed that thiamine 20 mM had the best effect in inducing resistance to the pathogen. This vitamin was used for treating the tomato leaves in subsequent experiments. For investigation of the role of peroxidase in thiamine- induced resistance, NaN3 was used as a specific peroxidase inhibitor and phenolic contents were measured in infected samples treated with thiamine and NaN3 at 0, 24, 48 and 72 hours after inoculation. There was a considerable difference between the phenolics level in different samples at various time points investigated in this study. The phenolics level in the samples treated with NaN3 was lower than other treatments. As a result, considering the role of peroxidase in phenolics production, the inhabitation of peroxidase activity leads to a reduction of phenolics and decrease of resistance to the pathogen in the tomato leaves treated with thiamine together with NaN3.
    Conclusion
    The results obtained in this study revealed the great potential of thiamine, as an environmentally safe vitamin, for induction of defense responses and partial protection of tomato plants against the destructive necrotrophic fungus R. solani AG4 HG I. It can be concluded that peroxidase and phenolics have an important role in thiamine-IR in tomato- R. solani interaction.
    Keywords: Induced resistance, Peroxidase, Solanum lycopersicum, Total phenol, Vitamin B1
  • M. University Of Tehran, A. R. Bandani, Gh. Sabahi Pages 449-459
    Introduction
    Tomato leaf miner Tuta absoluta Meyrick (Lep.: Gelechiidae) is one of the most important pest of tomato around the world which have been introduced to Iran in recent years. Pesticides can usually reduce the damage caused by the pest, however the extensive use of pesticides substantially increase production costs and lead to development of insecticide resistance. Thus, pest resistance and also adverse effects of pesticides on the human health and the environment make search for alternative control method/s inevitable. The aim of this study was to examine the effect of proteinaceous extracts of Datura (Datura stramonium L.), Bean (Phaseolus vulgaris L.), Wild Oat (Avena fatua L.), Broad bean (Vicia faba L.), Amaranth (Amaranthus retroflexus L.), Mung bean (Vigna radiate L.), Pea (Pisum sativum L.), Canola (Brassica napus L.), Triticale (Triticosecale wittmack) and Sivand, Aflak and Alborz wheat (Triticum aestivum L.) cultivars seeds on protease activity of tomato leaf miner. Also in this study optimum pH for protease activity and effects of pH on inhibitory activity of extracts were determined.
    Materials And Methods
    For this work fourth instar larvae of Tuta absoluta was used for enzyme extraction. Plant proteinaceous extracts were obtained using 0.1 M NaCl. For protease activity assay 10 μl enzyme extract and 50 μl substrate solution (Azocasein 2%) were mixed with 40 μl of the 20 mM Glycine-NaOH buffer at pH 10.0 After 60 min incubation, 100 μl of 30% trichloroacetic acid (TCA) was added to the reaction mixture, and kept at 4 °C for 30 min, followed by centrifugation at 15,000gfor 15 min to precipitate non-hydrolysis substrate. 100 μl of 1 M NaOH was added to 100μl supernatant and the absorbance at 405 nm was measured. To determine the effect of the seed proteinaceous extracts on the protease activities, enzymes were pre-incubated with each seed extracts for 30 min at 35 °C followed by determination of the residual enzyme activity as described before. To determine the effect of pH on inhibitory activity of the seed extracts, highest concentration of Mung bean, Pea, Canola, Broad bean, wild oat and two wheat cultivars (Alborz and Aflak) seed proteinaceous extracts were incubated along with the enzyme for 30 min at pH set at 6-12, and then enzyme activity was recorded as described before. Protein concentration was measured using bovine serum albumin (Bio-Rad, München, Germany) as a standard.
    Results And Discussion
    The effect of pH on protease activity showed that the greatest activity was observed at pH 10 and in the other pHs, it was lower, that this result Corresponded with the pH in other lepidopteran larvae. Also greatest activity of protease at alkaline pH indicates high activity of serine proteases in the alimentary canal. The greatest activity of protease was observed at 40 °C that wasn’t significant compared to 35°C. Effects of all seed proteinaceous extracts on protease activity were concentration dependent, so that the results showed that at the highest concentration, extracts of datura, bean, wild oat, broad bean, amaranth, mung bean, pea, canola, triticale and Sivand, Aflak and Alborz wheat cultivars inhibited the enzyme activity of the larvae with the percentage of 26, 25, 24, 40, 37, 33, 57, 53, 44, 43, 50 and 51, and the lowest concentration of seed extracts inhibited enzyme activity with the percentage of 11, 4, 6, 15, 8, 8, 16, 22, 11, 9, 13 and 16, respectively. Also the greatest inhibition of mung bean, pea, canola, broad bean, wild oat, Alborz and Aflak seed extracts were observed at alkaline pH which is the optimum pH for the activity of this enzyme in the in vitro condition. Due to the alkaline pH of lepidopteran larval gut lumen and maximum activity of protease, which occurs at the alkaline pH, it can be expected that in the in vivo condition, the extracts are impressed protease activity. However, complementary studies will be needed to achieve that.
    Conclusion
    Our results showed that the proteinaceous seed extracts have biological activity against the tomato leaf miner and therefore it may contribute towards the development of new insect pest control strategies. Thus, further study of these inhibitors including their purification, characterization and structure elucidation as well as the feasibility of their expression in transgenic host plants will unveil more detailed feature of the inhibitor.
    Keywords: Inhibition, Protease, Proteinaceous extracts, Tomato leaf miner
  • A. Bakhshani, E. Mahdikhani, Moghadam, S. Baghaee Ravari Pages 460-467
    Introduction
    Gossypium species are distributed in the arid to semiarid regions of the tropical and subtropical, generally shrubs or shrub-like plants. The leaves are broad and lobed with three to five lobes. The seeds are contained in a capsule called a "boll", each seed surrounded by fibers. Commercial species of cotton plant are Gossypium hirsutum (>90% of world production), G. barbadense (3-4%), G. arboreum and G. herbaceum (together, 2%). Cotton is grown as a cash crop; it is often grown in a monoculture system that favors the development of a nematode community dominated by one or a few parasitic species. The different genera of plant parasitic nematodes such as Haplolaimus, Helicotylenchus, Blanolaimus, Pratylenchus, Paratrichodorus, Meloidogyne, Merlinius, Xiphinema, Tylenchorynchus, Rotylenchulus, Scutellonema, Heterodera, Ditylenchus, Longidorus, Aphelenchoides, Aphelenchus were recorded from cotton fields in the world. The objective of this study was to investigate the plant parasitic nematodes associated with cotton fields in Southern Khorasan province of Iran.
    Materials And Methods
    In order to identify the plant parasitic nematodes in cotton fields in Southern Khorasan province, 56 soil samples were collected from different areas during 2013 and 2014. Soil samples were washed and nematodes were extracted by combined sieving and centrifugal-flotation method of Jenkins (1964) and Whitehead tray method (1965). Nematodes were fixed and transferred to glycerin by using the method of De Grisse (1969). The permanent slides were prepared and the nematodes were studied by light microscope.
    Results And Discussion
    In this study, 15 species from 10 genera related to order Tylenchomorpha, were identified as follows: Aphelenchus avenae, Basiria graminophila, Boleodorus clavicaudatus, B. pakistanensis, B. thylactus, Ditylenchus hexaglyphus, D. tenuidens, D. valveus, Geocenamus rugosus, Filenchus vulgaris, Pratylenchus neglectus, P. thornei, Scutylenchus quadrifer, Merlinius brevidens, Zygotylenchus guevarai. One genus of cotton-parasitic nematodes known to cause yield loss were found in this survey (Pratylenchus spp). Other parasitic nematodes not known to cause yield loss also were found. Three species, including Boleodorus pakistanensis, Ditylenchus hexaglyphus, D. valveus are reported as new records for Iran. Boleodorus pakistanensis is characterized by four incisures, head low, unstriated and conoid shape, stylet 8.5-10µm with cone short and slender knobs, non-muscular median bulb, Basal bulb pyriform, posterior vulva (v=68.1-72.4 ; v/=77.5-88.4). Tail elongate-conoid, central arcuate, ending in a finely rounded terminus. B. pakistanensis resembles, B. flexuosus B. teres, B. thylactus and B. cylindricus. B. thylactus but can be differentiated by the more posterior position of the opening of the dorsal gland (2 vs 3-5); B. flexuosus has a more anterior vulva (V=54-63 vs 68.1-72.4); B. teres has a more anterior vulva (V=54-63 vs 68.1-72.4), tail shape and stylet length (10-12 vs 8.5-10); B. cylindricus has a more anterior position of the opening of the dorsal gland (7 vs 3-5) and more tail (88-101 vs 72-88.5). Ditylenchus hexaglyphus is characterized by six lines in lateral fields, low head, stylet 8-9µm with cone shorter than the shaft and small elongated knobs, non-muscular median bulb, Posterior bulb offset, posterior vulva (v=82.3 -83.5; v/=87.8-89.6). Tail ventrally curved, terminus rounded. Having non-muscular median bulb, six incisures, short stylet and posterior vulva. D. hexaglyphus resembles D .medians, D. taylori, D. affinis, and D. tuberosus. However, none of these species have such small stylet knobs, and all but D. affinis have longer PUS than that observed in D. hexaglyphus. D. taylori more anterior vulva (V=75-77 vs 82.3-83.5) and tail appears to be thinner (c/=6-7 vs 2.9-3.8); D. affinis has a more anterior vulva (V=76-80 vs 82.3-83.5). Ditylenchus valveus is characterized by six incisures, annulated head, stylet 8-9µm with short cone and small rounded knobs, muscular median bulb with small. Posterior bulb offset, posterior vulva (v=74.3 -81.5; v/=84.9-89.2). Tail terminus rounded. Because of six incisures, short stylet, vulva position, oesophagus structure and tail shape, D. valveus resembles D. acutatus D. myceliophagus and D. medicaginis. D. myceliophagus differs from D.valveus by tail shape and generally overlapping oesophagus; D. medicaginis differs from D. valveus mainly by tail shape and also slightly more posterior vulva position (78-83 vs 74.3-81.5); D. acutatus differs from D. valveus mainly by tail shape.
    Conclusion
    In this study, 15 species from 10 genera of plant parasitic nematodes were identified. Among these genera and species, three species including Boleodorus pakistanensis, Ditylenchus hexaglyphus, D. valveus are reported as new records for Iran.
    Keywords: Boleodorus pakistanensis, Ditylenchus hexaglyphus, D. valveus, Nematode, Taxonomy
  • A. H. Nazemi, Gh. A. Asadi, R. Ghorbani Pages 468-480
    Introduction
    Human has always introduced various methods to control weeds. One of the best and the most modern methods is to use synthetic herbicides. The synthetic herbicides offer the same advantages compared to the other methods. They are selective, easy to apply, act quickly, relatively inexpensive, and can be used where other methods don’t work well. Therefore, their application have increased dramatically in the agricultural world and generated a series of additional problems such as herbicide resistance in weeds, soil and water pollution and the toxicity effects on human health and non-target species. With increasing global awareness about these disadvantages, the herbicidal potential of natural compound are focused because they have a short half-life and novel sites of action. Many natural compounds taken from many plant species, especially they are aromatic ones, have been studied for their herbicidal potential. For example, sorgoleone, isolated from Sorghum sp.; ailanthone, isolated from Ailanthus sp.; artemisinin, isolated from Artemisia sp.; coumarin, isolated from Ruta sp. and so on (5). The great interests in this field caused that the molecule of leptospermone isolated from Callistemon citrinus was optimized and then commercialized as mesotrione and sulcotrione herbicides (group F2/27) that inhibit p-hydroxyphenyl pyruvate dioxygenase (HPPD), a key enzyme in the biosynthesis of carotenoid and plastoquinone (9). Lavender (Lavandula sp.) is a medicinal plant with allelopathic properties which belongs to the Lamiacae family. The substantial components of lavender are made up of coumarin. Despite this, 18 structural analogues of coumarin extracted from lavender, coumarin itself had the most phytotoxic on Lolium sp. (9). The antibacterial, antifungal, insecticidal and herbicidal activities were demonstrated by the lavender essence. The current research aimed to determine the allelopathic potential of lavender essence on the germination indices of six plant species.
    Materials And Methods
    This study was separately and simultaneously carried out in 6 experiments based on a completely randomized design with four replications, which each one involved with one plant species. In each experiment, the influence of eight concentrations of coumarin including zero (control), 4, 20, 40, 100, 200, 300, and 400 ppm extract were assessed on germination and seedling growth of one plant species. There was 245 ppm coumarin from 100 g leaf of lavender. Weed species included redroot pigweed (Amaranthus retroflexus L.), common lambsquarters (Chenopodium album L.), barnyard grass (Echinochloa cruss-gali (L.) Moench), johnson grass (Sorghum halepense (L.) Pers.), common purslane (Portulaca oleracea L.); and corn crop (Zea mays L. cv. Sc 704). The seeds of all weeds were collected from weeds which were around fields located near Mashhad, Iran. The seeds of maize were obtained from the Agricultural and Natural Resources Research Center of Mashhad, Iran. Before the start of experiment, the seed dormancy-breaking treatments were conducted to increase the seed coat permeability of weed species. Hence, the seeds of A. retroflexus, C. album, E. cruss-gali, S. halepnse, and P. oleracea were acid-scarified in concentrated sulfuric acid (98%) for 5, 1, 3, 4 and 1 min, respectively; and then rinsed with distilled water. Twenty seeds of each plant species were placed in Petri dish on two layer of filter paper. Petri dishes were transferred into incubator after 10 ml of treatment solutions were added into them. Daily observations were made on the number of seeds germinated in each dish. After 12 days, root and shoot length was measured. Then, they were harvested and oven-dried at 75ºC for a period of 48 h and the dry weight was determined. The data were changed to individual plant and subjected to analyze by both the variance analysis using PROC GLM in SAS software.
    Results And Discussion
    Despite the differences between studied plants, the results indicated a high toxicity of lavender extract. All components of germination in all plants were significantly affected by lavender extract. Totally, allelopathic effects of extract from lavender increased with increasing its concentration and caused the germination percentage, the germination rate, the root and shoot length, and the seedling dry weight decreased. Low concentrations of lavender extract led to a stimulatory effect on seed germination common purslane, barnyard grass, johnson grass and corn. The results of this study showed that coumarin has the phytotoxic effect against Z. mays, S. halepnse, E. cruss-gali, A. retroflexus, C. album, and P. oleracea. Generally, Z. mays and P. oleracea were most tolerant and sensitive to coumarin.
    Conclusion
    The present study concludes that corn and common purslane had the highest and the lowest sensitivity to lavender extract, respectively. However, further studies are required to identify a selectivity index, using dose-response experiments to develop a selective or non-selective natural herbicide.
    Keywords: Corn, Coumarin, Weeds
  • N. Naerian, H. Farazmand, A. Avand Faghih, R. Vafaei, Shooshtari Pages 481-487
    Introduction
    The pomegranate fruit moth (PFM), Ectomyelois ceratoniae Zeller (Lep.: Pyralidae), is a polyphagous fruit pest in many tropical and subtropical regions. E. ceratoniae is the major pest of pomegranate orchards in Iran. PFM eggs are laid on or near the calyx, through which second or third instar larvae moving toward the center of it and consuming the interior tissue and seeds of the fruit. It is the most important reduction factor of quantitative and qualitative pomegranate yield in this country and its average damage is about 25%. Synthetic sex pheromone has been widely used for monitoring, timing spray and controlling methods. Insect sex pheromone traps, were used to determine the population density of the pest. In this study, the efficacy of sex pheromone traps, including trap type, height of trap, color of trap, trap situation, dose response, pheromone durability and host effect were studied.
    Materials And Methods
    For this purpose, seven series of field experiments were conducted in pomegranate orchards and the factors affecting the efficiency of pheromone traps including trap type and color, the height and situation of the trap, dose response, durability and effectiveness of pheromone trap host, were investigated in Tange-Siab (Koohdasht region) of Lorestan province (longitude 33°23″, latitude 47°12″, height of 856 meters above sea level). The experiments were conducted in a randomized complete block design with four replications, in early August to early September 2010-2011 years. To conduct research, a homogeneous garden (uniform age, variety and gardening conditions) was selected. The distance between the blocks was at least 100 meters. Each week, treatments situation on the block were determined by lottery and then were replaced. Data was analyzed based on a completely block randomized design using SAS software. Mean comparison was done using Duncan's test.
    Results And Discussion
    The results showed that, the delta trap was the best type, so it was captured 0.38 PFM moth/day and the tube and funnel traps have the minimum captures (0.13 PFM moth/day). Due to the possibility of passing air through delta traps and increasing the length of the tunnel pheromone, distribution of the pheromone molecules and as a result, insect attraction was more in delta trap compared to the other forms those. The comparison of trap heights showed that, height of 1.5 meter has the maximum capture (0.2 PFM moth/day) and height of 2.5 meter has the minimum capture (0.11 PFM moth/day). This phenomenon may be occured because of increasing altitude in which wind speed increases and pheromone molecules are transferred to further distance and so, moths are more exposed to them. The study on trap color showed that, white color was captured the highest moth (0.28 PFM moth/day) and black cone was captured the lowest moth (0.10 PFM moth/day). The studying on trap situation indicated that, south situation was captured the highest moth (0.25 PFM moth/day) and north one was captured the highest moth (0.12 PFM moth/day). The comparison of dispenser number in trap showed that, two pheremone dispensers trap (0.48 PFM moth /day) and control (0.04 PFM moth/day) treatments had the maximum and minimum captures, respectively. It was also found that the two dispensers in each trap had the best performance in the moth capturing. In other words, with the gradual increase of the pheromone concentration using two dispensers, the more insects were attracted, but less than tow dispensers per trap, the number of trapped moths decreased. The findings about the durability of sex pheromone illustrated that the best time intervals to change the pheromone dispenser are once a week (0.3 PFM moth/day). The results revealed that, changing of dispensers on 7th or 14th days, had the best performance in the moth capture. Also, the results showed that, the trap installation on wooden base was the best choice with capturing of 0.67 PFM (moth/day). It was found that, different kinds of shape and kairomones of the trees were not effective in attracting male insects.
    Conclusion
    As a result, the most suitable conditions for the usage of synthetic pheromone trap of pomegranate fruit moth, delta-type trap with color white which was set in the pomegranate trees south and 1.5 meter height. Two pheromone dispensers per trap were the best and the best time to replace pheromone dispenser was two weeks. The effect of trap place on the attraction of moth insects showed that trap, set on wooden base, had the highest efficiency.
    Keywords: Monitoring, Pheromone trap, Pomegranate pests, Synthetic pheromone
  • Mehdi Nasr Esfahani Pages 488-493
    Introduction. Sugar beet cyst nematode, Heterodera schachtii Schmidt is the major disease of sugar beet worldwide, causing considerable damages, and even death of the plants, in the infested fields. There are several suggested methods of controls, which may have its own difficulties to be taken into consideration. To avoid the use of nematicides, and reduced the risk of chemical hazards in the environment, any sorts of nonchemical management is incorrigible. However, any method of management must be safe, large scale application and economical. Thus, in this manuscript, polyethylene sheaths were used to solarize and or disinfection of the infested soils to H. schachtii. And, also, the incorporation of the farm yards manure was taken into consideration too. Therefore, the field experiments were carried out in infected sugar beet growing regions, where there was a heavy infestation to the sugar beet nematodes, Isfahan province, Iran, to determine the effects of soil solarization alone and or along with undecomposed farm yard manure on sugar beet cyst nematode, H. schachtii.
    Material and Methods. Transparent Polyethylene sheaths of 2microns were used to solarize and or disinfection of the infested soils to H. schachtii. The fresh farm yards manure for 40 tons per hector for the incorporation was taken into consideration. The field experiments were carried out in infected sugar beet growing regions, where, there was a heavy infestation to the sugar beet nematodes, Jey and Ghahab of Isfahan, Isfahan province, Iran, for determination of the effects of soil solarization alone and or along with undecomposed farm yard manure on sugar beet cyst nematode, H. schachtii.
    Treatments were consisted of soil solarization with transparent polyethylene sheets, fresh yard manure, integration of soil solarization with farm yard manure and untreated, control and or ckecks in a randomized block design in three replications each in an infested field conditions, in the hottest periods of the year, Jun - July. The experiments were repeated for the two years. Before, the covering of the soil, a very heavy irrigation was performed to wet the soil plots deeply, up to 60 cm. The considered factors were, the number of cyst and eggs and second larvae per gram of soils before and after the experiments. The related data on final population of cysts, number of eggs and second larvae per cyst and per gram of soil were subjected to statistical analysis. The reproduction factor and the percent reduction and or increasing population of sugar beet cyst nematode were taken into consideration in comparison to initial population of every treatment in the first and second years.
    Results and Discussions. The result revealed that, among all the treatments, the combination of soil solarization along with fresh yard manure had great and significant effects on the total nematode population reduction in the first, second and in the mean of the both years. Then, followed by of both trials of soil solarization and fresh yard manure treatments alone, with no significant difference in between. Also, the least reproductive factors in first, second as well as both years were 0.04, 0.003 and 0.021, which were attributed to combination of soil solarization with fresh farm yard manure. Population levels of the nematodes showed a descending trend in this treatment. Furthermore, the second effective treatment on population density 95, 98 and 96.5 percent and reproductive reductions 0.05, 0.02 and 0.035 in the first, second and both trials was in this treatment respectively. Combined analysis of variance showed that, in both of the years, in the first and second years of study, no significant differences, with an average of 83.27 and 108.08 in both the field before the treatments application, had the highest number of population. Other treatments except for the control of these two factors did not show significant differences (P = 0.01), solarization and fresh farm yard manure in compare to checks.
    Conclusions. It can be concluded from the results of these experiments that, the combination of fresh yard manure and soil solarization is having the greatest effects in reducing the sugar beet cyst nematode population in the sugar beet. Whereas, the manure and solarization alone were not statistically different from each other and both were together in one group, as compared to the combination of manure and solarization and of the control and or checks.
    Keywords: beet cyst nematode, Soil solarization, Farm yard manure
  • R. Khakzad, R. Valiolahpor, M. T. Alebrahim Pages 494-504
    This experiment was conducted to evaluate the performance of different herbicides on weed control and yield of ratoon rice as a randomized complete block design with four replications during 2012 at the Pasha Cola village of Sari- Iran. The treatments were: Anilofos Ethoxysulfuron (3 lit ha-1), Butachlor (3 lit ha-1) Cinosulfuron (100 g ha-1), Bensulfuron methyl (75 g ha-1) Butachlor (3 lit ha-1), Butachlor (3 lit ha-1), Cinosulfuron (100 g ha-1), Bensulfuron methyl (75 g ha-1) with a two-step weeding and weedy treatment (control). Results showed that the Sulfonylurea group herbicides such as Cinosulfuron and Bensulfuron methyl reduced density and dry weight of weed on the one hand and density and dry weight of weed in total on the other hand during the growing season. This leads to increase in ratoon rice yield at the end of the growing season. In addition to results showed that the Butachlor does not affected density and dry weight of weeds it caused reduction in weight of 1000 grain and yield of ratoon rice.
    Keywords: Anilofos+ Ethoxysulfuron, Butachlor, Cinosulfuron, Bensulfuron methyl
  • A. H. Jalali, H. Esfandiari Pages 505-517
    Introduction
    More than 7 thousand hectares of wheat and barley fields, in Isfahan province, and 200 thousand hectares of wheat and barley fields in Fars province has been infected by wild barley (Hordeum spontaneum Koch.). Wild barley is an annual, winter, diploid (2n = 14) plants, with the fragile axis and self-pollinating flowers. Wild oat seeds, after being separated from the mother plant at a depth of 1-3 cm left, and later in next winter sprouted. Conservation tillage and crop rotation are including the components of integrated weed management. Crop rotation because of a certain type of plant and its associated management of weeds in the rotation can provide a different habitat for weeds. Summer and winter plant crop rotation, plant diversity in a crop rotation, the use of reduced tillage systems and attention to the impact of plant residues, including those that are important in rotation. Tillage methods are considered as a way to control weeds. Although most researchers have agreed to increase the number of weeds in reduced tillage systems due to scattered non-sexual organs, in the case of annual weeds, some researchers believe the rise, and some believe that reducing the number of weeds in reduced tillage systems.
    Materials And Methods
    To study changes of weed density of weeds in wheat, especially wild barley, a three-year study (2011 to 2014) by using split plot randomized experiment based on a randomized complete block design with three replications was conducted in the Ardestan city. Main factors were different tillage systems including conventional tillage (moldboard plow use), minimum tillage (using a field cultivator) and no-tillage and six different rotations formed the sub plots. The use moldboard plow tillage with a depth of 25 cm has full buried seeds of wild oats. No tillage system without disturbing the soil, weed seeds will be exposed to the outside environment. The area of the sub-plots of 16 square meters (4 × 4) and an area of about 250 square meters for each replication, which, considering the distance between replication, as well as streams of water the total experiment was 1400 square meters. Seed varieties, were obtained from Seed and Plant Improvement Institute. In every year, wheat grain yield, weed dry weight and density of weeds in different rotations was carried out. Dominant weeds in the experiment were wild barley, wild oat (Avena fatua L.) and Phalaris (Phalaris spp). Other weeds that were less dense and less distribution in experiment and classified as other weeds were: barley mouse (Bromus spp), wild mustard (Sinapis spp), Lepidium Draba (Cardaria draba L.) and wild millet (Setaria spp). Statistical analysis was conducted by using SAS software and statistical tests were compared with Duncan at 5 percent.
    Results And Discussion
    In the first year of experiment the effect of tillage on the number of wild barley density, wild oats dry weight, Phalaris dry weight, Oats dry weight (all at 5%) and the number of stem Wild Oats (at 1%) was significant statistically. The results showed in the growing season of (2012-2013), conventional tillage systems and barley cropping in the early rotation, respectively, with 5.33 plants, 13.33 stems and 33.33 g dry weights per square of wild barley showed the lowest amounts compared to the other plants in beginning of rotation and also fallow periods. Similar trends were observed for the other tillage systems, except that the amounts of plant, stems dry weight of wild barley in no-tillage were higher than the other two systems. In the crop year of (2013-2014) maximum dry weights of wild barley (284.3 g m-2) was observed in the conventional tillage system and wheat crops in (canola - corn - wheat) rotation, respectively. The number of weed species present in the first and second year crops was respectively 3 and 7 species. In no tillage system compared with cultivator system, wild barley spike length was not significantly different, but in comparison with the moldboard was 13% longer. A similar trend was observed in the number of seeds produced by wild barley, and wild barley seed per square meter in no tillage systems was 40% higher. With regard to the initial contamination wild barely per square meter was 250 seeds per square meter, wild barely seed production after three years (two cropping seasons) and three moldboard plow tillage systems, field cultivator and soil tillage was still a considerable amount and can be a source of pollution for the next year. In simple terms, similar to the present study, short-term rotation despite the positive trend is still not a complete management to control this weed. In summary, the use of conventional tillage systems and the cultivation of crops belong to Poaceae family (except of barley) can be considered as factors increasing wild barley.
    Keywords: Moldboard plow, No tillage, Residue, Wheat
  • A. Derakhshan, M. R. Moradi, Telavat, S. A. Siadat Pages 518-532
    Introduction
    Seed germination is one of the key stages in the life cycle of plants that can ultimately affect their fitness in the environment. The temporal pattern of seed germination is extremely depended on the soil water potential (Ψ) of the germination medium, as this determines the equilibrium water content of the seed. As for temperature, there is a minimum Ψ that must be exceeded in order for seeds complete germination, and seeds in a population vary in the value of this minimum or base Ψ. The germination of a seed population in response to the reduced water potential is modeled using the hydrotime model. According to this model, the time to germination for a given seed fraction (g) is inversely related to the difference between the current seed Ψ and the base water potential (Ψb) for that fraction (Ψb(g)). The hydrotime model functions are well in matching both the timing and the percentage of germination of seed populations in relation to their Ψ environment. In addition, the model outputs which are significant physiologically and ecologically and the parameters of the model can be used to characterize the properties of seed populations. Normal distribution of Ψb among seeds within a population is one of the assumptions of the hydrotime model. However, this assumption may not be met in many species and thus can result in poor predictions. We tried to investigate empirically the validity of this assumption, to compare the fit of alternative distributions and make recommendations to improve germination modeling procedures.
    Materials And Methods
    Seed germination of Melilotus officinalis, Sinapis arvensis and Hordeum vulgare were tested across a range of water potentials (0, -0.2, -0.4, -0.6 and -0.8 MPa for M. officinalis and S. arvensis and 0, -0.3, -0.6, -0.9, -1.2 and -1.5 MPa for H. vulgare) and germination responses were described by the hydrotime models based on twelve statistical functions including Normal, Beta, Gamma, Loglogistic, Weibull, Gumbel, Birnbaum-Saunders, Inverse-normal, Log-normal, logistics, Rayleigh and Inverse-gamma. Four replicates of 50 seeds were spread evenly within 9-cm-diameter Petri dishes, each containing a Whatman No 1 filter paper. Each filter paper was moistened with 6 mL of polyethylene glycol (PEG) solutions or distilled water (0 MPa). Osmotic solutions were prepared by dissolving PEG 6000 in distilled water according to the Michel (1983) equation. Germinated seeds (radicle protrusion of>2 mm) were counted daily two or three times for 20 days. All distributions, having been formulated into the hydrotime model, were fitted to data using the PROC NLMIXED procedure of SAS, with the default optimization technique of dual quasi-Newton algorithm.
    Results And Discussion
    The results showed that the estimated parameters of the hydrotime model developed on the basis of Beta distribution had more certainty than the other distributions (AICc=-556.60 for M. officinalis, AICc=-847.70 for S. arvensis and AICc=-1034.20 for H. vulgare). Based on the Beta hydrotime model, values of the hydrotime constant (θH) and water potential threshold for beginning of M. officinalis seed germination (δ) were estimated to be 14.01 MPa h and -0.85 MPa, respectively. For S. arvensis, θH and δ estimated to be 22.23 MPa h and -0.98 MPa, respectively. Estimated θH and δ for H. vulgare was 48.69 MPa h and -2.47 MPa, respectively. Results of this research are in contrast to assumption of a normal distribution of base water potential of a seed population. Hence, before using a hydrothermal time model to make predictions, the distribution of base water potential within a seed sample should be examined and an appropriate equation should be selected.. The results indicated that among all three species, the Beta distribution resulting in more accurate predictions than the other distributions. The hydrotime model based on Beta distribution predicts an actual value for the phase of delay germination. In fact, less skewed in predicted germination using beta model can be related to more accurately of this function to predict the onset of germination. Shape parameter gives high flexibility to this model and allows more accurate prediction of delayed germination phase. In addition, the hydrotime model based on Beta distribution was able to prediction germination of species for which the base water potential distribution is symmetrical or unsymmetrical.
    Conclusion
    In this paper, a model based on the beta distribution is proposed which is not only more biologically relevant, but also provides better predictions of germination compared to the conventional model.
    Keywords: Base water potential, Beta model, Cumulative distribution function, Modeling
  • Marzie Mazhari, M.R. Tadayon Pages 533-536
    Introduction
    Weeds limit crops growth, development and yield through adjacency and competing and seed dormancy is a problem in controlling of weeds. Man has been always tried to optimize crop yield through weeds controlling. Weeds seed bank in the soil can affected weed management and their control methods. So identifying seed bank characters has important role in choice of management methods in seeds of many plant species which cannot germinate despite favorable environmental conditions. Main reasons for this problem, which is termed as seed dormancy, are hard and impermeable seed coat and presence of immature or dormant embryo. To break dormancy, a variety of methods are in vogue worldwide these days. Of all different methods of breaking dormancy, treatment of seed with certain chemicals including different types of plant growth regulators (PGRs) is contemplated as the most effective one. Gibberellic acid (GA3) is the most widely used PGR to improve seed germination in different plant species. Also, nitrate (such as KNO3) clearly stimulates the germination of dormant seeds. KNO3 is the most widely used chemical for promoting germination. Solutions of KNO3 are common in routine germination testing and are recommended by the Association of Official Seed Analysts and the International Seed Testing Association (ISTA) for germination tests of many species.Stratification refers to the method of placing seeds in layers alternating with layers of a moisture retaining medium, such as sand, peat or vermiculite, and keeping them at a cool temperature for a certain period, but it varies considerably from species to species. The combination of high moisture and low temperature appears to trigger off biochemical changes which transform complex food substances into simpler forms utilized by the embryo when it renews growth at germination. The use of the word “stratification” has recently been extended to include all forms of cold, moist treatment whether or not the seeds are placed in layers. Chilling plays an important role in providing the stimulus required to overcome dormancy, increase germination, and produce normal seedlings for Prunuspersica. Exogenous growth regulator treatments – gibberellins (usually gibberellic acid GA3 and GA4) and cytokinins (usually kinetin, benzyladenine) – have been shown to break dormancy in many seed species. The objective of the present study was to investigate effective methods in breaking the seed dormancy of Teragopogon collinus and Descurarina sophia and evaluate their response to different dormancy-breaking treatments, germination under different constant and alternating temperature, and using chemical, with most appropriate dormancy-breaking procedure for both species.
    Materials And Methods
    In order to evaluate the effect of different treatments on dormancy breaking and seed germination of Teragopogon collinus and Descurarina sophia an experiment was carried out as factorial based on a Randomized Complete Block Design (RCBD) with three replications at Shahrekord University in 2012. Treatments including different levels of gibberellic acid (0, 100, 250 and 500 mg) at two soaking time levels of 2 and 24 hour (along with scarification pre-treatment), concentrations of potassium nitrate (50, 100 and 150 mM) in 10 and 30 minutes (along with scarification pre-treatment), treatment of rotational temperature (5-15 and 10-20 °C), in full light, dark and rotational light periods (8 hr light and 16 hr dark) and mechanical treatments of dormancy breaking (application of boiling water).
    Results And Discussion
    Teragopogon collinus and Descurainia sophia had highest seed dormancy breaking under rotational temperature and light and application of gibberellic acid and potassium nitrate (along with scarification pre-treatment) had no effect on Teragopogon collinus and Descurarina sophia dormancy. According to the Teragopogon collinus and Descurainia sophia seeds dormancy breaking in mechanical treatments and the effect of rotational temperature and light, it can be concluded that the dormancy of Teragopogon collinus and Descurainia sophia seeds are intermittent. The results showed that the effect of temperature, time, and the interaction of light ×time of germination percent of Teragopogon collinus and Descurainia sophiawere were significant at 1%.The interaction between light and alternating temperature on Teragopogon collinus seed germination suggests that intermittent lighting conditions at alternating temperatures, increase the germination percentage of Teragopogon collinus. According to the Teragopogon collinus and Descurainia sophia seeds dormancy breaking in mechanical treatments and the effect of rotational temperature and light, it can be concluded that the dormancy of Teragopogon collinusan and Descurainia sophia seeds are intermittent.
    Keywords: Chemical treatments, Rotational temperature, light, Seeds, Weed
  • Fatemeh Khandehroo, Gholamhossein Moravaj, Hussein Sadeghi Namaghi, Lida Fekrat Pages 537-540
    During sampling on species diversity of arthropods associated with ash trees in Mashhad and vicinity, a number of specimens of parasitoids from Eulophidae were collected in May 2013. They were identified by Dr. Lütfiye Gençer (Cumhuriyet University of Turkey) as: Aprostocetus catius (Walker, 1839), Chrysocharis pubicornis (Zetterstedt, 1838), Neochrysocharis chlorogaster (Erdös, 1966), Asecodes erxias (Walker, 1848). These species were reported for the first time from Iran. Eulophidae is the largest family in the Chalcidoidea including over 3900 species, 540 genera and four subfamilies including Euderinae, Eulophinae, Entedoninae, Tetrastichinae. So far, 106 species belonging to 37 genera in four subfamilies (Entedoninae, Euderina, Eulophinae, Tetrastichinae) from Iran have been recorded.
    Keywords: Ash tree, Parasitoid wasp, Mashhad
  • Gholam Reza Doraki, Gholam Reza Zamani Pages 541-546
    Introduction
    Stalked Bur Grass (Tragus racemosus L.) is an angiosperm annual plant with C4 photosynthesis pathway and stolon. It grows in hot and dry summers. This plant spreaded throughout the world from hot regions of Africa. It is regularly seen in barren lands or in between the generations with sequential initial stages with light-texture soils. Seed dormancy is in fact a physiological phenomenon which is observed in the seeds of most crops, pasture plants, medicinal herbs and weeds. Dormancy allows the plant to guarantee its germination and survival for long years and to survive through adverse environmental conditions through its spatial and temporal spread.
    Materials And Methods
    In order to evaluation dormancy break of Tragus racemosus L. seeds, an experiment was carried out based a Randomized Complete Block Design with four replications in research laboratory of Department of Agriculture, Birjand University during 2013. The initial experiments showed that the seeds of Stalked Bur Grass had initial dormancy and were unable to germinate at normal conditions, so that less than 5% of the seeds germinated. The studied treatments for breaking seeds dormancy included control (seeds disinfection by distilled water), wet chilling at 4°C for 1, 2, 3 and 4 weeds, treatment with H2SO4 at 97% for 20, 40, 60 and 80 seconds, treatment with KNO3 at 0.2, 0.4, 0.6 and 0.8% for 24 hours and treatment with Gibberellic acid (GA3) at 50, 100, 200 and 400 ppm. In this study, 25 seeds of Stalked Bur Grass were uniformly placed in petri dishes with the diameters of 9 cm on Watmann filter papers and were applied with 5 mL distilled water. The number of germinated seeds was counted on a daily basis for 21 days. In the end, germination percentage and rate was determined.
    Results And Discussion
    The results revealed that the effect of all studied levels of all treatments were significant on germination percentage and rate. The highest germination percentage (76%) was observed under wet chilling treatment at 4°C for 4 weeds and the lowest one (6%) was observed in control. The highest germination percentage under H2SO4 treatment was 41% obtained at the level of 80 seconds, under KNO3 treatment was 69% obtained at the level of 0.8%, and under GA3 treatment was 62% obtained at the level of 400 ppm. The highest germination rate (18.24 seeds per day) was observed at KNO3 treatment (0.8%) and the lowest one (0.91 seeds per day) was observed in control. In addition, the highest germination rate under H¬2SO4 treatment was 15.28 seeds per day obtained at the level of 80 seconds, under wet chilling was 13.25 seeds per day obtained at the level of 3 weeks, and under GA3 treatment was 12.08 seeds per day obtained at the level of 200 ppm. Wet chilling enhances the production of such stimulants as gibberellins. On the other hand, chilling treatment may reduce ABA amount or the sensitivity of embryo to ABA which can play a role in seeds dormancy breaking. KNO3 is likely to increase the sensitivity of germinating seeds to light acting as a complement factor for phytochrome which results in higher germination of the seeds. Most researchers believe that dormancy is broken by the balance between growth inhibitors like abscisic acid and growth stimulators like gibberellins. In addition, gibberellins activate a special signaling pathway that reduces abscisic acid in seeds and in contrast, auxins and cytokinins of the seeds are increased to a level enough for inducing dormancy break.
    Conclusion
    In the present study, the germinated seeds were counted for 21 days. The highest germination percentage (76%) was observed under wet chilling treatment for 4 weeks and the lowest one (6%) was observed under control treatment. The highest germination rate (18.24 seeds per day) was observed under KNO3treatment (0.8%) and the lowest rate (0.91 seeds per day) was reported under control treatment. According to the results it can be concluded that the dormancy of Stalked Bur Grass seeds belongs to physiological dormancy type.
    Keywords: Germination percentage, Gibberellic acid, Moist chilling, Potassium nitrate, Sulfuric acid