فهرست مطالب

  • سال هجدهم شماره 2 (پیاپی 68، 1399)
  • تاریخ انتشار: 1399/04/11
  • تعداد عناوین: 8
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  • روح الله سرورزاده، حمیدرضا خزاعی*، احمد نظامی صفحات 139-151

    به منظور تعیین اثر نیتروژن و تنش کم آبی بر خصوصیات ریشه و عملکرد دانه ذرت رقم (SC. 704)، آزمایشی طی سال زراعی 1394 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد انجام شد. نیتروژن در دو سطح (100 و 200 کیلوگرم در هکتار از منبع اوره) و آبیاری در شش سطح (آبیاری کامل، تنش متوسط کم آبی در مرحله 4 تا 6 برگی، تنش شدید کم آبی در مرحله 4 تا 6 برگی، تنش متوسط کم آبی در مرحله 4 تا 6 برگی و ادامه آبیاری با کم آبیاری، تنش شدید کم آبی در مرحله 4 تا 6 برگی و ادامه آبیاری با کم آبیاری، کم آبیاری بعد از مرحله 6 برگی) بر روی گیاهان اعمال شد. برای اعمال تنش متوسط 55، برای تنش شدید 45 و برای اعمال کم آبیاری 65 درصد رطوبت ظرفیت زراعی در نظر گرفته شد و آبیاری بعد از رسیدن رطوبت خاک در عمق توسعه ریشه به مقادیر ذکر شده انجام شد. نتایج نشان داد که آبیاری مجدد به همراه کود سرک نیتروژن منجر به تسریع بیشتر رشد گیاهانی شد که در شرایط تنش شدید کم آبی و کمبود نیتروژن قرار گرفته بودند. اندازه گیری ها در مرحله کاکل دهی ذرت نشان داد اثر نیتروژن و آبیاری بر شاخص کلروفیل، شاخص سطح برگ، تعداد ریشه های هوایی، عملکرد، کارایی زراعی مصرف نیتروژن و کارایی جذب نیتروژن در (P≤0.05) معنی دار شد، ضمن این که اثر نیتروژن بر تعداد و زوایای ریشه های طوقه ای، تعداد ریشه های جانبی در ریشه های طوقه ای در (P≤0.05) معنی دار بود. با وجودی که بیشترین عملکرد با مصرف 200 کیلوگرم نیتروژن در هکتار و آبیاری کامل به مقدار 11640 کیلوگرم در هکتار و کمترین عملکرد با مصرف نیتروژن به مقدار 100 کیلوگرم در هکتار و تنش شدید کم آبی در مرحله 4 تا 6 برگی و کم آبیاری متعاقب آن به مقدار 6490 کیلوگرم در هکتار به دست آمد، کاهش عملکرد در تنش متوسط کم آبی در مرحله رویشی معادل 11 درصد بود که نشان دهنده مقاومت نسبی گیاه ذرت در این مرحله به تنش کم آبی و سازگاری در شاخساره و ریشه ها برای تعدیل اثر تنش کم آبی در شرایط این آزمایش است.

    کلیدواژگان: ریشه های طوقه ای، ریشه های هوایی، کارایی زراعی مصرف نیتروژن
  • رقیه آقایی اوخچلار، رضا امیرنیا*، مهدی تاجبخش شیشوان، مهدی قیاسی صفحات 153-165

    به منظور بررسی تاثیر محلول پاشی عصاره کودهای آلی بر خصوصیات زراعی و عملکرد کمی و کیفی شش اکوتیپ بادرشبو، آزمایشی به صورت فاکتوریل در قالب طرح بلوک کامل تصادفی با سه تکرار در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه ارومیه در دو سال زراعی 1394 و 1395 به صورت کشت بهاره انجام گرفت. تیمارهای آزمایشی شامل اکوتیپ های بادرشبو در شش سطح (ارومیه، سلماس، عجب شیر، تهران، اصفهان و شیراز) و محلول پاشی کودهای آلی 10 درصد در پنج سطح (شاهد، کود گاوی، کود مرغی، ورمی کمپوست و کمپوست) بود. صفات مورد مطالعه شامل وزن خشک کل، وزن هزار دانه، عملکرد بذر، عملکرد بیولوژیک، شاخص برداشت دانه، عملکرد و درصد اسانس بود. نتایج تجزیه واریانس مرکب داده ها نشان داد که اعمال تیمارهای محلول پاشی و اکوتیپ بر صفات وزن خشک کل، وزن هزار دانه، عملکرد بذر، عملکرد بیولوژیک، شاخص برداشت دانه، عملکرد و درصد اسانس در سطح احتمال یک درصد معنی دار شد. اثرات متقابل اکوتیپ و محلول پاشی بر صفات وزن هزار دانه و شاخص برداشت دانه در سطح احتمال یک درصد و بر صفات عملکرد و درصد اسانس در سطح احتمال پنج درصد معنی دار بود. نتایج نشان داد بیشترین مقدار وزن هزار دانه، شاخص برداشت دانه، عملکرد اسانس و درصد اسانس به ترتیب به مقدار 3/2 گرم، 93/21 درصد، 42/9 کیلوگرم در هکتار و 99/0 درصد مربوط به تیمار محلول پاشی کود مرغی و اکوتیپ ارومیه بود. بیشترین مقدار وزن خشک کل و عملکرد بذر به ترتیب به مقدار 1/994 و 3/331 کیلوگرم در هکتار مربوط به اکوتیپ ارومیه و محلول پاشی کود مرغی به ترتیب به مقدار 7/896 و 5/304 کیلوگرم در هکتار حاصل شد. در نهایت با توجه به نتایج حاصل از این تحقیق کاربرد تیمار محلول پاشی عصاره کود مرغی و اکوتیپ ارومیه در منطقه ارومیه و کشت اکوتیپ های بومی در سایر مناطق در زراعت بادرشبو توصیه می شود.

    کلیدواژگان: تغذیه برگی، درصد اسانس، گیاه دارویی، متابولیت های ثانویه
  • پرویز رضوانی مقدم*، قربانعلی اسدی، بهاره بیچرانلو صفحات 167-180

    به منظور بررسی کارایی مصرف نور در نسبت های جایگزینی کشت مخلوط ذرت و کدو پوست کاغذی، آزمایشی در قالب طرح بلوک های کامل تصادفی با سه تکرار در مزرعه ای واقع در 10 کیلومتری غرب شهرستان شیروان در سال 1394 اجرا شد. تیمارهای آزمایش شامل نسبت های جایگزینی 75% ذرت+ 25% کدو پوست کاغذی، 50% ذرت + 50% کدو پوست کاغذی و 25% ذرت + 75% کدو پوست کاغذی و کشت خالص هر یک از گیاهان بود. نتایج حاکی از وجود رابطه خطی بین تجمع ماده خشک هر دو گیاه با تشعشع فعال فتوسنتزی تجمعی در تیمارهای مختلف کشت مخلوط با ضریب همبستگی بیشتر از 9/0 بود. کارایی مصرف نور برای ذرت از 92/0 گرم بر مگاژول در نسبت 25 درصدی ذرت در کشت مخلوط تا 35/4 گرم بر مگاژول در کشت خالص و کارایی مصرف نور برای کدوی پوست کاغذی از 87/0 گرم بر مگاژول در نسبت 75% کدوی پوست کاغذی: 25% ذرت تا 7/3 گرم بر مگاژول در کشت خالص آن متغیر بود. بیشترین میزان تشعشع جذب شده کل در بین نسبت های مختلف کشت مخلوط، در نسبت 50% (کدو پوست کاغذی): 50% (ذرت) و نسبت 75% (کدو پوست کاغذی): 25% (ذرت) مشاهده شد که در زمان بین 110-70 روز پس از کاشت میزان تشعشع جذب شده کل پوشش گیاهی حداکثر و با میزان تشعشع رسیده به پوشش گیاهی هم پوشانی داشت. بالاترین مقدار شاخص برداشت ذرت (5/59) در نسبت 75% کدوی پوست کاغذی: 25% ذرت و بالاترین مقدار شاخص برداشت کدوی پوست کاغذی (1/24) در نسبت 50% کدوی پوست کاغذی: 50% ذرت به دست آمد. بیشترین نسبت برابری زمین برای کارایی مصرف نور ذرت و کدوی پوست کاغذی در نسبت 25% کدوی پوست کاغذی: 75% ذرت و سپس در نسبت 50% کدوی پوست کاغذی: 50% ذرت (به ترتیب 49/5 و 04/5) مشاهده شد که بالاترین میزان شاخص برداشت را نیز نشان دادند.

    کلیدواژگان: پوشش گیاهی، تشعشع فعال فتوسنتزی، جذب نور، شاخص سطح برگ، عملکرد
  • جواد مشکانی، محمد کافی، سرور خرم دل*، فاطمه معلم بنهنگی صفحات 181-196

    گیاهان دارویی منبع غنی از ترکیبات فعال زیستی محسوب می شوند و می توانند در درمان بسیاری از بیماری ها به عنوان جایگزینی ایمن در مقایسه با داروهای شیمیایی استفاده شوند. بهره گیری از کشت مخلوط موجب بهبود کارآیی مصرف منابع و بروز اثرات متقابل مفید بین گیاهان همراه می گردد. این سیستم کشت همچنین موجب کاهش انتشار بیماری های گیاهی از طریق کاهش تعداد گیاهان میزبان حساس می شود. این مطالعه با هدف بررسی اثر کشت مخلوط سری های جایگزینی زیره سبز و موسیر بر خصوصیات زراعی دو گیاه شامل عملکرد، اجزای عملکرد، شاخص برداشت، میزان تجمع ماده خشک و نسبت برابری زمین انجام شد. این آزمایش در قالب طرح بلوک های کامل تصادفی با سه تکرار در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد در سال زراعی 94-1393 انجام شد. نسبت های کشت مخلوط جایگزینی شامل 20% موسیر + 80% زیره سبز، 40% موسیر + 60% زیره سبز، 50% موسیر + 50% زیره سبز، 60% موسیر + 40% زیره سبز، 80% موسیر +20% زیره سبز و کشت خالص هر دو گونه بودند. تراکم غده های موسیر و بذر زیره سبز در تیمار کشت خالص به ترتیب برابر با 10 و 120 بوته در متر مربع در نظر گرفته شد. صفات مورد مطالعه شامل تعداد چتر در بوته، تعداد دانه در چتر، وزن هزار دانه، عملکرد دانه و بیولوژیک زیره سبز و میزان تجمع ماده خشک موسیر و زیره سبز و همچنین قطر پیاز دختری، قطر پیاز مادری، وزن تر پیاز دختری، وزن تر پیاز مادری، عملکرد بیولوژیک و عملکرد تر و خشک پیاز و نسبت برابری زمین بودند. نتایج نشان داد که اثر نسبت های کشت مخلوط جایگزینی بر عملکرد و اجزای عملکرد زیره سبز و موسیر معنی دار بود (05/0≤P). با تغییر نسبت کاشت از کشت خالص به سمت کشت مخلوط صفات مورد مطالعه آن بهبود یافت. به طوری که قطر پیاز مادری و تولید پیاز دختری در نسبت های کشت مخلوط نسبت به کشت خالص به ترتیب 52 و 68 درصد افزایش نشان دادند. بالاترین عملکرد پیاز خشک برای کشت خالص (9/82 گرم در متر مربع) و 20% زیره سبز+ 80% موسیر (3/85 گرم در متر مربع) مشاهده شد. همچنین بیشترین عملکرد دانه زیره سبز از کشت خالص با 115 گرم در متر مربع به دست آمد. بیشترین نسبت برابری زمین مربوط به تیمار 50% زیره سبز+ 50% موسیر (49/1) و کمترین مقدار برای تیمار 80% زیره سبز + 20% موسیر (15/1) بود. کشت مخلوط دو گیاه موسیر و زیره سبز اثر معنی داری بر عملکرد و اجزای عملکرد و نسبت برابری زمین داشت. بر این اساس، نتایج موید افزایش عملکرد، بهبود بهره وری و افزایش ثبات تولید دو گونه موسیر و زیره سبز در کشت مخلوط می باشد.

    کلیدواژگان: اثر متقابل، ثبات عملکرد، حفاظت خاک، کارآیی مصرف منابع، گیاهان دارویی
  • هانیه حاجی شعبانی، فرزاد مندنی*، علیرضا باقری صفحات 197-212

    به منظور شبیه سازی اثرات تاریخ کاشت بر رشد و عملکرد نخود دیم منطقه کرمانشاه توسط مدل CROPGRO-CHICKPEA، آزمایشی به صورت کرت های خرد شده در قالب طرح پایه بلوک های کامل تصادفی با 3 تکرار در مزرعه تحقیقاتی پردیس کشاورزی و منابع طبیعی دانشگاه رازی در سال زراعی 96-1395 اجرا شد. تیمارها شامل سه تاریخ کاشت (10 اسفند، 20 اسفند و 17 فروردین) به عنوان عامل اصلی و چهار رقم نخود (بیونیج، عادل، آرمان و ILC482) به عنوان عامل فرعی بود. ضرایب ژنتیکی ارقام توسط بخش محاسبه ضرایب ژنتیکی برای تاریخ کاشت 10 اسفند محاسبه شد. نتایج واسنجی نشان داد مدل قادر است با حداقل اختلاف، ویژگی های رشد و نمو را برای ارقام نخود شبیه سازی کند که بیانگر دقت بالای ضرایب ژنتیکی محاسبه شده بود. نتایج ارزیابی های مدل نشان داد که میانگین nRMSE وزن خشک کل برای ارقام مورد بررسی 5/16 درصد میانگین مشاهده ها بود. میانگین nRMSE عملکرد دانه نیز برای ارقام ذکر شده 5/13 درصد میانگین مشاهده ها بود. هم در شرایط مزرعه و هم در شبیه سازی تاخیر در کاشت منجر به کاهش عملکرد نخود شد. بیشترین عملکرد دانه مشاهده شده و شبیه سازی شده برای سال زراعی 96-1395 به ترتیب، 6/1326 و 6/1279 کیلوگرم در هکتار در تاریخ کاشت 20 اسفند حاصل شد. به طور کلی نتایج نشان داد که مدل CROPGRO-CHICKPEA قادر است واکنش ارقام نخود در تاریخ کاشت های مختلف را تحت شرایط اقلیمی منطقه مورد مطالعه با دقت قابل قبولی پیش بینی کند که این نشان دهنده دقت بالای ضرایب ژنتیک محاسبه شده در بخش واسنجی مدل است.

    کلیدواژگان: ارقام نخود، عملکرد دانه، نمو فنولوژیک، واسنجی مدل
  • کمال حاج محمدنیا قالی باف*، محمد بنایان اول، محمد حسن راشد محصل، نیوشا ولایی، فاطمه یعقوبی، زهرا رشیدی صفحات 213-224

    به منظور بررسی تاثیر سطوح آبیاری، تاریخ کاشت و تراکم بوته بر عملکرد، اجزای عملکرد و کارایی مصرف آب گیاه دارویی زیره سبز آزمایشی در سال زراعی 1397-1396 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد به صورت کرت های خرد شده در قالب طرح بلوک های کامل تصادفی با سه تکرار اجرا شد. عامل اصلی شامل سطوح آبیاری 100، 75 و 50 درصد ظرفیت زراعی، سه تاریخ کاشت در ماه های آذر، اسفند و فروردین به عنوان عامل فرعی و دو تراکم کاشت 40 و 80 بوته در مترمربع عامل فرعی فرعی در نظر گرفته شدند. نتایج نشان داد آبیاری کامل زیره سبز در آذر ماه با تراکم 80 بوته در مترمربع دارای بیشترین تعداد چتر در بوته، تعداد دانه در چتر و عملکرد دانه بود. در حالی که در شرایط مشابه با کاهش تراکم، وزن 100 دانه و وزن تک بوته افزایش و کارایی مصرف آب کاهش یافت. تیمارهای آبیاری 75 و 50 درصد ظرفیت زراعی در فروردین ماه با تراکم 40 بوته در متر مربع به ترتیب با کاهش 77/53 و 20/52 درصدی عملکرد دانه نسبت به کاشت آن در آذر ماه با آبیاری کامل و تراکم 80 بوته در مترمربع، دارای کمترین مقدار بود. همچنین، سطوح آبیاری 100 و 75 درصد ظرفیت زراعی در ماه های اسفند و فروردین با تراکم 80 بوته در مترمربع به ترتیب علی رغم کاهش 83/12، 24/29، 43/21 و 11/35 درصدی عملکرد دانه نسبت به کاشت در آذر ماه با آبیاری 100 درصد ظرفیت زراعی و تراکم مشابه، دارای بیشترین کارایی مصرف آب بودند. بنابراین، با افزایش تراکم بوته در واحد سطح همراه با آبیاری متوسط (75 درصد ظرفیت زراعی) در کشت های دیر هنگام (اسفند و فروردین) می توان تا حدودی کاهش عملکرد دانه زیره سبز را با افزایش کارایی مصرف آب جبران نمود.

    کلیدواژگان: تعداد چتر در بوته، تنش خشکی، ظرفیت زراعی، عملکرد دانه، فاصله ردیف
  • فرزین پورامیر، بیژن یعقوبی، یاسر علی زاده* صفحات 225-239

    به منظور بررسی میزان جذب و کارایی مصرف نور و همچنین تعیین ضریب استهلاک نوری در سه ژنوتیپ برنج در تراکم های مختلف کشت مستقیم، آزمایشی به صورت فاکتوریل در قالب طرح پایه بلوک های کامل تصادفی با سه تکرار و 15 تیمار در مزرعه تحقیقاتی موسسه تحقیقات برنج کشور- رشت اجرا شد. تیمارهای مورد مطالعه شامل پنج تراکم بذر (65، 80، 95، 110 و 125 کیلوگرم بذر در هکتار) و سه ژنوتیپ برنج (لاین امید بخش طاهر، رقم آنام و رقم هاشمی) بودند. نتایج نشان دادکه بیشترین عملکرد دانه در رقم طاهر (6380 کیلوگرم در هکتار) و رقم آنام (6100 کیلوگرم در هکتار) در تراکم 95 کیلوگرم بذر در هکتار به دست آمد ولی بیشترین عملکرد دانه در رقم هاشمی (5490 کیلوگرم در هکتار) در تراکم 110 کیلوگرم بذر در هکتار مشاهده شد. در این تحقیق، بیشترین (06/3 گرم بر مگاژول PAR) و کمترین (20/2 گرم بر مگاژول PAR) میزان کارایی مصرف نور به ترتیب در تراکم های 95 و 125 کیلوگرم لاین طاهر مشاهده شد. دو ژنوتیپ آنام و طاهر در تراکم 95 کیلوگرم در هکتار به ترتیب با 773 و 852 مگاژول PAR بر متر مربع و رقم هاشمی در تراکم 110 کیلوگرم در هکتار با 880 مگاژول PAR بر متر مربع، بالاترین میزان جذب تشعشع در طول فصل رشد را داشتند. افزایش تراکم تا سطح مطلوب در ارقام برنج باعث افزایش جذب و همچنین کارایی مصرف نور گردید. بین جذب و کارایی نور با عملکرد زیستی و دانه ارقام برنج همبستگی مثبتی مشاهده شد.

    کلیدواژگان: رقم هاشمی، سایه‎اندازی، شاخص سطح برگ، ضریب خاموشی نور
  • فائزه شرقی، ابراهیم خلیل وند بهروزیار* صفحات 241-250

    به منظور بررسی اثر محلول پاشی نانو ذرات دی اکسید تیتانیوم و اسید سالیسیلیک بر تعدیل اثرات مخرب تنش کمبود آب در ذرت هیبرید سینگل کراس 704، آزمایشی به صورت اسپلیت پلات فاکتوریل در قالب طرح پایه بلوک های کامل تصادفی با سه تکرار در ایستگاه تحقیقاتی دانشکده ی کشاورزی دانشگاه آزاد اسلامی واحد تبریز طی سال زراعی 1397 اجراشد. عامل اصلی تنش کمبود آب در سه سطح 50، 75 و 100 درصد رطوبت قابل دسترس و ترکیب فاکتوریلی کاربرد نانو دی اکسید تیتانیوم (n-TiO2) (در سه سطح صفر، 01/0 و 03/0 درصد) و اسید سالیسیلیک (SA) (در دو سطح صفر و نیم درصد) به عنوان عامل فرعی در نظر گرفته شد. نتایج حاصل از تجزیه واریانس داده ها نشان داد که اثر محلول پاشی  n-TiO2و SA تحت سطوح مختلف تنش کمبود آب بر صفات فعالیت آنزیم کاتالاز، آسکوربات پراکسیداز در سطح احتمال پنج درصد و محتوای کلروفیل a، b و کلروفیل کل در سطح احتمال یک درصد معنی دار بود. همچنین اثر محلول پاشی SA تحت تنش کمبود آب بر صفت سوپراکسید دیسموتاز در سطح احتمال پنج درصد معنی دار بود. اثر متقابل محلول پاشی n-TiO2 در سطوح مختلف تنش کمبود آب نیز بر صفت سوپراکسید دیسموتاز در سطح احتمال یک درصد و اثر محلول پاشی n-TiO2 و SA نیز بر صفت سوپراکسید دیسموتاز در سطح احتمال پنج درصد معنی دار بود. نتایج نشان داد که محلول پاشی با 01/0 درصد نانو دی اکسید تیتانیوم تحت شرایط 50 درصد رطوبت قابل دسترس بیشترین فعالیت آنزیم سوپر اکسید دیسموتاز را داشت. همچنین محلول پاشی با 01/0 درصد نانو دی اکسید تیتانیوم و 5/0 درصد اسید سالیسیلیک تحت رطوبت 50 درصد قابل دسترس بیشترین مقدار فعالیت آنزیم کاتالاز را به خود اختصاص داد. کاربرد 01/0 درصد نانو دی اکسید تیتانیوم و 5/0 درصد اسید سالیسیلیک در شرایط آبیاری کامل در مقایسه با عدم کاربرد نانو دی اکسید تیتانیوم و اسید سالیسیلیک تحت آبیاری 50 درصد رطوبت قابل دسترس به ترتیب 79 درصد، 5/2 برابر و 82 درصد محتوای کلروفیل a، b و کلروفیل کل را افزایش داد. در این مطالعه کاربرد نانو ذرات دی اکسید تیتانیوم و اسیدسالیسیلیک با افزایش فعالیت آنزیم های سوپر اکسید دیسموتاز، کاتالاز و آسکوربات پراکسیداز موجب تعدیل اثرات منفی تنش کمبود آب گردید. همچنین با توجه به این که نانو ذرات دی اکسیدتیتانیوم و اسید سالیسیلیک بر آنزیم های تاثیرگذار بر فیزیولوژی گیاه اثرات مثبتی داشتند از این رو میزان تولید دانه ذرت نسبت به شاهد و شرایط کم آبیاری افزایش قابل ملاحظه ای نشان داد.

    کلیدواژگان: آسکوربات پراکسیداز، سوپر اکسید دیسموتاز، کاتالاز، محتوای کلروفیل، محلول پاشی
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  • R Sarwarzadeh_H. R Khazaei*_A .Nezami Pages 139-151
    Introduction

    In recent years regulated deficit irrigation as a part of conservation and saving practices in water consumption has received attention. Vegetative growth stage of corn has a relative tolerance to water deficit stress. Therefore, yield loss is negligible. Nitrogen shortage stress leads to decrease in leaf area, leaf senescence and reduction of photosynthesis as a result of decrease in chlorophyll content. Roots play an important role in soil searching for water and nutrients. Root ability to change soil biochemical and physiological processes consider as a remarkable mechanism to tolerate environmental stress. Considering the role of nitrogen in corn production and irrigation in summer crops, understanding the response of corn to water stress and nitrogen consumption level are important. Furthermore, corn growth recovery after water deficit stress is critical for better understanding of water saving techniques. This study designed to determine morphological change in root of corn and their effect on corn yield under different irrigation and nitrogen levels.

    Materials and Methods

    In order to evaluate the impact of different levels of nitrogen consumption and water deficit stress on corn (SC 704) in field condition, an experiment conducted during 2015 in the experimental field of Ferdowsi University of Mashhad. Nitrogen levels were, including 100 and 200 kg ha-1and irrigation applied in 6 levels, including W1: complete irrigation, W2: moderate water stress (55% of field capacity) at V4-V6 growth stage, W3: severe water stress (45% of field capacity) at V4-V6 growth stage, W4: moderate water stress (55% of field capacity) at V4-V6 growth stage followed by deficit irrigation (65% of field capacity), W5: severe water stress (45% of field capacity) in V4-V6 growth stage followed by deficit irrigation (65% of field capacity), W6: deficit irrigation (65% of field capacity) after V6 growth stage. Effect of water deficit stress and re-watering concurrently with two levels of nitrogen consumption attested by crop growth rate index between stress time and 10 days after rewatering. Furthermore at silking stage, SPAD, leaf area index, the number and angle of crown and brace roots, grain yield, agronomic nitrogen use efficiency, nitrogen uptake efficiency and nitrogen harvest index measured and calculated.

    Results and Discussion

    Result showed that under severe water stress re-watering at the same time with applying nitrogen led to faster growth. Effects of nitrogen and irrigation were significant on SPAD, leaf area index, the number of brace roots, grain yield, agronomic use efficiency and nitrogen uptake efficiency in 5% probability level, while effect of nitrogen on number of crown root, angle of crown root and number of lateral root in crown root were significant at 5% probability level (p-value < 0.05). Grain yield had a significant and positive correlation with leaf area index, the number of brace roots and SPAD, whereas yield had a negative correlation with brace root angle. Despite highest yield obtained under the consumption of 200 kg ha-1 nitrogen with complete irrigation, yield reduction due to water deficit at V4-V6 growth stage was 6% which shows the relative tolerance of corn to water deficit stress during aforementioned growth stage and effective tolerance of root and shoot of corn for minimizing the consequences of water stress on our experiment condition.

    Conclusions

    Although highest grain yield obtained with consumption of 200 kg ha-1 nitrogen with complete irrigation, flexible management with considering availability of water and nitrogen during vegetative growth stage lead to maximum profitability. Relative tolerance of corn seedling to water deficit stress and growth recovery of crop makes it possible to save water. Flexibility of corn root number and angle can be used in breeding program to obtain hybrids with more effective nitrogen use efficiency.

    Keywords: Agronomic nitrogen use efficiency, Brace root angle, Crown root angle
  • R .Aghaee Okhchelar, R .Amirnia*, M .Tajbakhsh shishvan, M .Ghiyasi Pages 153-165
    Introduction

    Today, medicinal plants have a special place in the pharmaceutical, food and cosmetic industries. Moldavian balm (Dracocephalum Moldavica L.) is an herbaceous annual plant belonging to the Lamiaceae family. In foliar application of plant nutrients the transfer rate of nutrients from the surface of the leaves to various organs of the plant has a great effect, particularly when leaves reach their maximum level. In this method, nutrients are directly aerobic and there is no problem of sediment accumulation in soil and its ability to use. Ecotype characteristics is another factor affecting the components of the medicinal plant. depends on s. This research was carried out in order to evaluate the importance of organic medicinal plants and the advantages of using organic fertilizers and their extracts to improve the quality of active ingredients, maintain soil and environmental contamination.

    Materials and Methods

    This research was carried out at the research farm of the Faculty of Agriculture, Urmia University, located at Nazlou campus, during two season of 2014 and 2015.The land preparation operations included plowing, leveling and cutting was performed in the fall of first year. Sowing was carried out on April 15th. First, the seeds of ecotypes were weighed. Then the seeds of each ecotype were divided equally into the plots to be planted. Seed sowing was done manually and uniformly in each plot. The dimensions of the plots were 2×2 meters. The blocks were spaced one and a half meters apart. The plots were then irrigated regularly. Weed control was carried out manually and mechanically during the growing season in two stages. The application of spraying treatments in vegetative growth stage was carried out in two stages in the first and fifth of June according to the experimental design with manual sprayer. Sampling was done at the end of flowering in August. Samples in each experimental plot with an area of one square meter were harvest. Essential oil was extracted from dry specimens. For this purpose, 40 g of each sample was weighed, and this amount was put into a 1000 ml bécher  after being crushed for the purpose of extraction of the essential oil with a Clevenger apparatus.

    Results and Discussion

    The results of combined analysis of variance showed that application of spraying treatments and ecotypes on total dry weight, 1000 seed weight, seed yield, biological yield, grain harvest index, yield and essence percentage were significant at 1% probability level (p-value < 0.01). The interaction of ecotype and spraying application on 1000 seed weight and grain harvest index were significant at 1% probability level (p-value < 0.05) and on yield and essence percentage were significant at 5% probability level (p-value < 0.05). The results showed that the highest amount of 1000 grain weight, grain harvest index, yield and essence percentage were 2.3 g, 76.76%, 9.42 kg ha-1 and 0.99%, respectively belonged to poultry manure spraying and Urmia ecotype. The highest total dry weight and seed yield belonged to Urmia ecotype (969.5 and 875 kg ha-1 respectively) and poultry manure spraying (892.5 and 756.7 kg ha-1, respectively) were obtained. Finally, according to the results of this research, application of poultry manure spraying and ecotype of Urmia in Urmia region and cultivation of native ecotypes in other regions is recommended.

    Conclusions

    The results of this study showed that foliar application of organic fertilizer extracts has significant effects on studied traits. Therefore, application of organic fertilizers can be a suitable alternative for chemical fertilizers and is recommended. Considering the significant importance of ecotypes on the studied traits, choosing the suitable ecotype for each region is economically feasible.

    Keywords: Essence percentage, Foliar feeding, Medicinal herb, Secondary metabolites
  • P .Rezvani Moghaddam*, G. A. Asadi, B. Bicharanloo Pages 167-180
    Introduction

    Mixed cropping is one of the oldest and most commonly used agricultural activities in low-yield systems in many parts of the world. One of the factors contributing to the superiority of the mixed cropping to sole cropping is the correct selection of its components. When plants with a distinct root system and different canopy structures are placed next to each other, they occupy different ecological niches and have different spatial and temporal uses of environmental resources in a more efficient way than a combination of resources. Light is one of the main components of growth and production of dry matter of plants. In non-stressed conditions, dry matter production is a function of the time and amount of photosynthesis active radiation received, the fraction of radiation absorbed by the plant, and the efficiency of absorbed radiation converted to dry matter. Among these components, it is possible to improve the absorbance of photosynthetic active radiation by increasing leaf area index and canopy leaf arrangement. Due to the fact that maize leaves are placed in a more vertical arrangement, while absorbing better light, allows the light to penetrate into the lower canopy portions. On the other hand, Cucurbitaceae family plants because of the rapid covering of the surface of the land through crawling growth and the ability to grow in the shade, are most of the plants that are cultivated mixed with maize. Styrian oil Pumpkin (Cucurbita pepo L.) is an annual herbaceous plant which, due to its numerous medicinal properties, is one of the most important medicinal plants in the Cucurbitaceae family. Therefore, in maize and Styrian oil pumpkin mix cropping, most of the light is absorbed by the maize canopy surface due to its higher height and a different morphological structure, than the Styrian oil pumpkin and the rest of the light that passes through the upper layers is absorbed by the Styrian oil pumpkin canopy and hence, the efficiency of light consumption will be maximized. The aim of this study was to investigate the radiation use efficiency as an important aspect in crop growth and yield improvement.

    Materials and Methods

    In order to evaluate radiation use efficiency of maize and Styrian oil Pumpkin under different intercropping ratios, an experiment was conducted in a randomized completely block design with three replications in a field located in 10 km west of Shirvan, Iran in 2015. The experimental treatments were included intercropping replacement ratio of 75% maize: 25% Styrian oil Pumpkin, 50% maize: 50% Styrian oil Pumpkin, 25% maize: 75% Styrian oil Pumpkin and pure culture of both plants. A linear PAR Ceptometer (Sun Scan) was used to measure the radiation at top and under the canopy to calculate the amount of absorbed radiation by the canopy.

    Results and Discussion

    The results showed that there was a linear relationship between dry matter accumulation of both plants with cumulative photosynthetically active radiation. The correlation coefficient between them was greater than 0.9 in different intercropping treatments. Radiation use efficiency of maize was varied from 4.35 g MJ-1 in monoculture (the maximum amount) to 0.92 g MJ-1 (the minimum amount) in 25% maize: 75% Styrian oil Pumpkin treatment. The maximum and minimum amount of radiation use efficiency of Styrian oil Pumpkin (3.7 and 0.87 g MJ-1) were observed in monoculture and 75% maize: 25% Styrian oil Pumpkin treatments. The highest amount of total absorbed radiation among different intercropping ratios, was obtained in 50% maize: 50% Styrian oil Pumpkin and 25% maize: 75% Styrian oil Pumpkin. The maximum amount of total radiation absorbed by the canopy obtained70-110 days after sowing date. The results showed that canopy in mixed cropping treatment absorbed all received radiation in 70-110 days after sowing date. The maximum harvest index of maize (59.5) and Styrian oil pumpkin (24.1) was obtained from 25% maize: 75% Styrian oil pumpkin and 50% maize: 50% Styrian oil pumpkin, respectively.

    Conclusions

    The results indicated that there was a linear relationship between accumulation of dry matter of both plants and cumulative active photosynthesis radiation in different cropping treatments with correlation coefficient greater than 0.9. The slope of this line, which shows the efficiency of light consumption, varied from 4.35 g MJ-1 to pure maize, up to 0.92 g MJ-1 in the 25% maize ratio, and the highest and lowest amount of light consumption efficiency of Styrian oil pumpkin (3.7 and 0.87 g MJ-1) were observed in pure crop and 25% ratio of Styrian oil pumpkin, respectively.

    Keywords: Canopy, Leaf area index, Photosynthetic active radiation, Radiation absorption, Yield
  • J. Meshkani, M. Kafi, S. Khorramdel*, F. Moallem Benhangi Pages 181-196
    Introduction

    Medicinal plants are a rich source of bioactive compounds, and these plants are thought to be safe to human beings and the environment compared to the synthetic medicines for the treatment of many diseases. The active principles of the plants are generally secondary metabolites. Cumin (Cuminum cyminum L.) is an herbaceous and annual medicinal plant belonging to Apiaceae family which is planted in arid and semi-arid regions of Iran. Persian shallot (Allium altissimum Regel.) is another medicinal, industrial and perennial plant that has underground bulbs. It is one of the most important Allium species in Iran, which normally grows in semi-cold to very cold highlands. In the last decade, agricultural production, which is mainly based on the application of chemical inputs, is causing environmental impacts. The use of ecological farming approaches, enhancing yield and quality, they will be effective. Intercropping allows for improved resource use efficiency such as light, water and nutrients and beneficial interactions between the companion plants. It works to decrease the spread of plant diseases by reducing the quantity of susceptible host plants. Other benefits of intercropping include optimal use of resources, stabilization of yield, weed control, improved soil fertility, and higher economic returns. This study has evaluated the effect of intercropping ratios as replacement series of cumin and Persian shallot on agronomic criteria such as yield components, yield, harvest index, dry matter accumulation and land equivalent ratio.

    Materials and Methods

    This experiment was conducted based on a randomized complete block design with three replications at the Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad during growing season of 2014-2015. Intercropping ratios as replacement series such as 80% cumin+20% Persian shallot, 60% cumin+40% Persian shallot, 50% cumin+50% Persian shallot, 40% cumin+60% Persian shallot, 20% cumin+80% Persian shallot and their pure culture were considered as treatments. Plant density for Persian shallot bulbs and cumin seeds were considered as 10 bulbs.m-2 and 120 plants.m-2, respectively. Studied traits were umbel numbers per plant, seed numbers per umbel, 1000-seed weight, biological yield and seed yield of cumin and daughter bulb diameter, mother bulb diameter, fresh weight of daughter bulb, fresh weight of mother bulb, biological yield, fresh yield of bulb, dry weight of bulb of Persian shallot and land equivalent ratio (LER).The LER was computed through the following equation:Where, Yij: Yield of cumin under intercropping conditions, Yji: Yield of Persian shallot under intercropping conditions, Yii: Yield of cumin under sole crop conditions and Yjj: Yield of Persian shallot under sole crop conditions. The treatments were run as an analysis of variance (ANOVA) to determine if significant differences existed among means. Multiple comparison tests were conducted for significant effects using the LSD test.

    Results and Discussion

    The results showed that the effect of intercropping ratios was significant (p≤0.05) on yield and yield components of cumin and Persian shallot. By decreasing intercropping ratios of Persian shallot improved its criteria. Diameter of mother bulb and production of daughter bulb in intercropping ratios were increased up to 52 and 68% compared to sole culture, respectively. Studied traits of cumin were improved by changing in planting ratios from intercropping to its pure culture. The maximum amounts of dry bulb weight were related to pure culture (82.9 g.m-2) and 20% cumin+80% Persian shallot (85.3 g.m-2). The highest seed yield of cumin was observed in pure culture with 115 g.m-2. The highest and the lowest LER were computed in 50% cumin+50% Persian shallot (1.49) and 80% cumin+20% Persian shallot (1.15).

    Conclusions

    Intercropping of Persian shallot and cumin had significantly effect on their yield and yield components. The results confirmed the better use of resources especially for radiation and water of these plants in intercropping ratios. In general, it seems that intercropping may be suitable cropping approach for sustainable production of medicinal plants. Acknowledgement This research was funded by Vice Chancellor for Research of Ferdowsi University of Mashhad, which is hereby acknowledged.

    Keywords: Beneficial interaction, Medicinal plants, Resource use efficiency, Soil conservation, Stabilization of yield
  • H. Hajishabani, F. Mondani*, A. Bagheri Pages 197-212
    Introduction

    Simulation crop models allow to represent growth, phenological development and yield of crops and to evaluate new technologies or conditions not yet explored. The DSSAT (Decision Support System for Agrotechnology Transfer) is one of the most widely used modeling systems across the world. The DSSAT was developed with a modular structure to facilitate its maintenance and to include additional components to simulate cropping systems, considering different soils, climates, and management conditions. The DSSAT has also proven to be a useful tool for selecting improved agricultural practices. Currently, the DSSAT is able to incorporate models of 27 different crops, including several cereal grains, grain legumes, and root crops. The CROPGRO-Chickpea model is part of the DSSAT model. This model allows simulating the development and yield of the grain legumes, to represent and to evaluate the influence of multiple environmental and agronomic factors. Among all management practices, selecting optimum sowing date helps in minimizing the effect of high temperatures during the grain filling period responsible for reduction of grain yield. Therefore, the objectives of the present study were: (1) to estimate the genetic coefficients and calibrate the CROPGRO-Chickpea model (2) to evaluate the performances of the CROPGRO-Chickpea model in simulating chickpea cultivars growth, development and grain yield in different sowing dates under Kermanshah climatic conditions.

    Materials and Methods

    This experiment was carried out in a split-plot design with three sowing dates (28 February, 10 March and 6 April) as main plots and 4 current chickpea cultivars (Bivanij, Adel, Arman and ILC482) as sub plots with three replications at 2017. The required model inputs consisted field management, daily weather conditions, soil profile characteristics, and cultivar characteristics. The cultivar coefficients were obtained under optimum conditions (i.e., minimum stress in weather and nutrients). The genetic coefficients of the chickpea cultivars i.e. Bivanij, Adel, Arman and ILC482 were determined using the GenCal software of DSSAT v 4.6 for sowing date of 28 February treatment. Model performance was evaluated by comparing simulated and measured values of chickpea cultivars phonological development stages (DVS), leaf area index (LAI), total dry weight (TDW) and grain yield (GY) for another sowing date treatments (10 March and 6 April) by root mean square error (RMSE), normalized RMSE (nRMSE) and index of agreement (d).

    Results and Discussion

    The results of model calibration showed that there were very good agreements between the DVS, LAI, TDW and GY of observed and simulated values. The results of the model validation also indicated that the CROPGRO-Chickpea model was able to accurately simulate DVS and yield for chickpea cultivars. The nRMSE values for Bivanij, Adel, Arman and ILC482 of LAI were 26.1, 27.9, 28.3 and 20.1%, respectively. The index of agreement (d) for LAI ranged from 0.8 to 0.9. The nRMSE average for evaluated cultivars of TDW was 16.5%. The index of agreement (d) for TDW was 0.99. The nRMSE average for evaluated cultivars of GY was 13.5%. The index of agreement (d) for GY ranged from 0.96 to 0.98. For both simulated and measured conditions the late sowing date led to reduce in the grain yield. The greatest grain yield of simulated and measured were 1279.7 and 1326.6 kg ha-1 that related to sowing date of 10 March 2017 treatment.

    Conclusions

    Based on the results of model calibration, it can be concluded that the estimated of genetic coefficients by the GenCalc software were very robust in simulating the phenological development stages and growth of chickpea. The results of model validation showed that the CROPGRO-Chickpea model was able to give an accurate simulation of all studied traits of chickpea cultivars except leaf area index in different sowing date under Kermanshah climate conditions.

    Keywords: Chickpea cultivars, Grain yield, Model calibration, Phonological development
  • K. Hajmohammadnia Ghalibaf*_M. Bannayan Aval_M. H Rashed Mohassel_N. Valaei_F .Yaghoubi_Z. Rashidi Pages 213-224
    Introduction

    Supplies of irrigation water are severely limited and water use efficiency (WUE) has become more vital, especially for valuable drought tolerant plants. Green cumin (Cuminum cyminum L.) is a medicinal and spices plant adapted to arid and semi-arid regions such as Iran. Planting date, irrigation and plant density can affect quality and quantity of cumin. Seed yield of cumin decreases by increasing water deficit, despite absorbing water even in very low water potentials. Changes in planting date can also affect water use efficiency due to rainfall and evapotranspiration (ET) differences between each season. Therefore, crop yield should increase in parallel with decreasing water consumption (or evapotranspiration) for optimal water use and increasing WUE. Additionally, different plant densities and late or early planting dates could affect morphological traits and grain yield.

    Materials and Methods

    In order to study the effects of planting date, deficit irrigation and plant density on yield, yield components and WUE of cumin, a field experiment was conducted as split-split plot based on randomized complete block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad during growing season of 2017-2018. The main plots were irrigation levels including 100, 75 and 50% field capacity (FC). Three planting dates were studied in the split plots (December, March and April) and two plant densities (40 and 80 plant m-2) arranged as split-split plots. Soil moisture content was determined a day before and two days after each irrigation with TDR. Then, irrigation was done based on treatments during the growth period. Number of umbel per plant, number of seed per umbel, 100-seed weight, plant weight, seed yield and WUE were measured at the end of growing season. Analysis of variance were calculated using R software and Duncan's multiple range test was used at 5% probability level to compare the averages.

    Results and Discussion

    The results showed that the full irrigation (100% FC) of cumin in December with 80 plants m-2 had the highest number of umbel per plant, number of seed per umbel and seed yield, whereas, 100-seed weight and plant weight increased and WUE decreased with decreasing density (40 plants m-2) under 100%FC during December. The lowest seed yield were obtained from 75 and 50% FC in April with 40 plants m-2 (53.77% and 52.20% respectively) compared with December with 100% FC and 80 plants m-2. Seed yield were decreased by irrigation levels of 100 and 75% FC in March and April with 80 plants m-2 12.83, 29.24, 21.43 and 35.11%, respectively compared with 100% FC in December (80 plants m-2), despite the highest WUE. Therefore, increasing plant density with medium irrigation in late planting dates (March and April) can partially compensate decreasing cumin seed yield by increasing WUE. The correlation analysis showed that 100-seed weight and plant weight had significant negative correlation with WUE in full irrigation and two levels of water deficit. However, there was no significant correlation between WUE and seed yield under both levels of water deficit and full irrigation conditions.

    Conclusions

    The results of this study indicate that seed yield can be improved by increasing plant density when rainfall is proportional to plant water requirement in autumn and winter. In addition, increasing plant density in medium irrigation (75% FC) conditions in late planting dates (March and April) can increase WUE and produce high economic value.

    Keywords: Field capacity, Number of umbel per plant, Row spacing, Seed yield, Water stress
  • F. Pouramir, B.Yaghoubi, Y. Alizade* Pages 225-239
    Introduction

    Effective use of sunlight is a great opportunity to improve crop productivity. In conditions without growth limiting factors, there is a linear relationship between radiation absorption and dry matter production in plants, that the slope of this relationship is radiation use efficiency. In addition to genotyping, radiation use efficiency is affected by crop management. Changes in density of rice varieties by affecting leaf area index and light extinction coefficient change the amount of absorption and distribution of light within the canopy and thus affect dry matter production. Therefore, the response of different rice cultivars to change in density is not same. According to this, the present study was carried out to investigate the radiation absorption and efficiency of use and also determine the light extinction coefficient in new and old rice cultivars at different direct seeding densities in Rasht climatic conditions.

    Material and Methods

    The present experiment was carried out as a factorial based on randomized complete block design with three replications at research field of Rice Research Institute of Iran-Rasht. Treatments included five levels of densities (65, 80, 95, 110, and 125 kg ha-1) and three levels of cultivar (Taher (promising line), Anam and Hashemi). Sampling was performed once every two weeks, 25 days after emergence. Sampling was performed with 0.5×0.5 m quadrates to measure leaf area, dry weight, and radiation in different treatments.

    Results and Discussion

    The results showed that the interaction effect of cultivar and density on radiation use efficiency, LAI, grain and biological yield were significant. Harvest index was affected only by density and light extinction coefficient was not affected by any density and cultivar treatments. The highest grain yield of Taher (6380 kg ha-1) and Anam cultivars (6100 kg ha-1) were obtained in 95 kg ha-1 density, while the highest yield of Hashemi cultivar (5490 kg.ha-1) was observed in 110 kg ha-1 density. Grain yield followed biological yield, and treatments with higher biological yield had higher grain yield. The highest leaf area index (5.63) was observed in Hashemi cultivar and 110 kg ha-1 density in 70 days after emergence. At this stage, the lowest leaf area index (4.21) was observed in Taher cultivar at 65 kg ha-1 density. Although, in the early stages of growth, higher densities had a higher rate of leaf area expansion, but the highest leaf area index did not differ significantly between 95, 110, and 125 kg ha-1 densities. The light extinction coefficient of this experiment varied from 0.4 to 0.5 in different cultivars and densities and Taher cultivar had the higher light extinction coefficient. Although, no significant difference was observed between treatments. The highest grain yield of Taher (6380 kg ha-1) and Anam (6100 kg ha-1) cultivars were obtained in 95 kg ha-1 density, but the highest yield of Hashemi (5490 kg ha-1) was obtained in 110 kg ha-1. In this study, the highest (3.06 g MJ-1 PAR) and the lowest (2.20 g MJ-1 PAR) radiation use efficiency were observed at 95 and 125 kg ha-1 of Taher cultivar, respectively. In all cultivars, the lowest radiation use efficiency was observed at density of 125 kg ha-1. Anam and Taher cultivars had the highest radiation absorption (773 and 852 MJ-1 PAR, respectively) during the growing season at 95 kg ha-1. Although, the highest radiation absorption of Hashemi (880 MJ-1 PAR) cultivar was obtained at 110 kg ha-1 density.

    Conclusions

    The results showed that Taher cultivar had the highest grain and biological yield compared to Anam and Hashemi cultivars. Based on yield, the best density was 95 kg ha-1 for Anam and Taher cultivars and 110 kg ha-1 for Hashemi cultivar. Increasing the density of rice cultivars to the optimum level increased the radiation absorption and use efficiency. There was a positive correlation between radiation absorption and efficiency with biological and grain yield of rice cultivars.

    Keywords: Hashemi cultivar, Leaf area index, Light extinction coefficient, Shading
  • F. Sharghi, E. Khalilvand Behrouzyar* Pages 241-250
    Introduction

    Drought is one of the most important causes of decline in agricultural productivity worldwide. TiO2 is one of the materials that nowadays, its properties have been reported to reduce environmental impact. TiO2 with increasing activity of PS II light reduction, activity of chloroplast photophosphorylation, rubisco enzyme, nitrate reductase enzyme activity, catalase and peroxidase and improving the content of some essential elements in plant tissues, increases the yield of different crops. Salicylate is one of the natural growth regulators and is a natural phenolic compound that contributes to the regulation of physiological processes in plants. In the study of the effect of nano-TiO2 spraying on some of the agronomy characteristics of wheat, 0.02% nano-TiO2 foliar application under drought stress conditions increased seed yield by 23% compared to non-foliar application. Considering that a large part of cultivated land in Iran has semi-arid climatic conditions and because of its special geographical position, in most parts of it, important abiotic stresses such as drought, salinity, and temperature decrease the yield and, in some cases, led also to failure of agriculture. Therefore, the aim of this study was to evaluate and identify important biochemical change of corn 704 single cross under water deficit stress and application of the TiO2 and salicylic acid compound.Materials and

    Methods

    In order to investigate the effect of nano-TiO2 and salicylic acid foliar application on some biochemical changes of corn 704 single cross under water deficit stress, an experiment was conducted in split plot factorial based on RCBD in three replications at the Research Station of the Islamic Azad University, Tabriz Branch, during growing seasons of 2017-2018. Treatments were three levels of water deficit stress (50, 75, and 100% filed capacity (FC)), three levels of the factorial combination of nano-TiO2 (n-TiO2) foliar application (non-application (control), 0.01, and 0.03), and two levels of salicylic acid (SA) foliar application (non-application and 0.5%). Field capacity was determined from the pressure plate machine. TiO2 foliar application on the shoot was performed three times during the growing season and in the stages of 8-10 leaf, tasselling, and grain filling. Irrigation was done according to the needs of the canopy and depending on the weather conditions of the region and irrigation treatments were applied from 8-10 leaves stage. superoxide dismutase (SOD) activity, catalase (CAT), ascorbate peroxidase (APX) activity, and chlorophyll (Chl) content were measured according to the Giannopolities and Ries (1977), Cakmak and Horst (1991), Nakano and Asada (1981), and Porra (2002) methods, respectively. The MSTAT-C software was used to analysis of variance and the means of the treatments were compared using the Duncan’s test at 0.05 probability level.

    Results and Discussion

    N-TiO2 and SA foliar application increased CAT, APX activity (p < 0.05) and content of Chl a, b, and total Chl (p < 0.01). Also, the interaction between SA and water deficit stress on SOD and interaction betweenn-TiO2 and SA on SOD (p < 0.05) was significant. Results showed that 0.01% n-TiO2 foliar application under 50% water deficit stress had the highest SOD. Furthmore, 0.01% n-TiO2 and 0.5% SA foliar application under 50% water deficit stress had the highest CAT. 0.01% n-TiO2 and 0.5% SA foliar application under complete irrigation had 79%, 2.5 times and 82 % more than Chl a, b and total Chl compare non-use of n-TiO2 and SA under 50% FC, respectively.

    Conclusions

    The results of this study showed that 0.01% n-TiO2 foliar application had the highest superoxide dismutase enzyme activity under 50 % FC. Also, 0.01% n-TiO2 and 0.5% SA foliar application under 50 % FC had the highest catalase enzyme activity. Use of 0.01% n-TiO2 and 0.5% SA under normal stress (50 % FC), increased 79%, 2.5 time and 82% Chl a, b and total Chl compare to control, respectively.

    Keywords: Ascorbate peroxidase, Catalase, Chlorophyll content, Foliar application, Superoxide dismutase