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مطالعات حفاظت گیاهان - سال سی و دوم شماره 1 (بهار 1397)

فصلنامه مطالعات حفاظت گیاهان
سال سی و دوم شماره 1 (بهار 1397)

  • تاریخ انتشار: 1397/03/22
  • تعداد عناوین: 16
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  • علمی - پژوهشی
  • علی باقری، حمید رحیمیان، مصطفی اویسی صفحات 1-9
    به منظور بررسی تاثیر دزهای کاهش یافته علف کش ایمازتاپیر بر علف های هرز لوبیا، آزمایشی مزرعه ای به صورت کرت های خرد شده در سه تکرار، در مزرعه تحقیقاتی پردیس کشاورزی و منابع طبیعی دانشگاه تهران در سال 1392 انجام گرفت. تیمارهای آزمایش شامل غلظت های علف کش ایمازتاپیر (1 لیتر در هکتار فرآورده تجاری با نام پرسوئیت با فرمولاسیون 10% SL به عنوان غلظت 100 درصد و غلظت های 25، 50 و 75 درصد از غلظت توصیه شده به همراه تیمار وجین (شاهد عاری از علف های هرز)) به عنوان کرت های اصلی و کشت جداگانه و مخلوط ارقام اختر (ایستاده) و گلی (رونده) به صورت ردیفی و با نسبت (1:1)، به عنوان کرت های فرعی اجرا شد. نتایج آزمایش نشان داد که تاثیر دزهای کاهش یافته علف کش در کاهش زیست توده علف های هرز بسته به نوع گونه علف هرز و رقم لوبیا متفاوت است. در بین علف های هرز غالب، حساسیت تاج خروس وحشی نسبت به سلمه تره و تاجریزی سیاه در برابر افزایش دز بیشتر بود. در تیمارهایی که از رقم رونده استفاده شد، به دلیل قدرت پوشانندگی بالاتر، وزن خشک علف های هرز کاهش بیشتری نشان داد. در میان تیمارهای آزمایش، بالاترین میزان عملکرد دانه از رقم گلی با 4237 کیلوگرم در هکتار از دز کامل به دست آمد. کاربرد 75 درصد دز توصیه شده باعث حصول عملکرد بالای 4000 کیلوگرم در رقم گلی شد، و در همین دز مقدار عملکرد از رقم اختر و کشت مخلوط به ترتیب 3617 و 3641 کیلوگرم، حاصل شد. همچنین با توجه به نتایج مجموع عملکرد نسبی (RYT)، این شاخص در دزهای 75، 100 و تیمار وجین به ترتیب 95/0، 87/0 و 001/1 بدست آمد. با توجه به این نتایج، می توان گفت که امکان استفاده از دزهای کاهش یافته این علف کش تنها در صورتی که گیاه زراعی با توانایی رقابت بالا بتواند قدرت رقابتی علف های هرز را کاهش دهد، امکان پذیر است.
    کلیدواژگان: دز های کاهش یافته، رقم، کشت مخلوط
  • سید اسماعیل روانگرد، سید وحید اسلامی، سهراب محمودی صفحات 11-19
    این آزمایش جهت ارزیابی اثر آفتاب دهی خاک بر کنترل علف هرز علف پشمکی Bromus tectorum L.)) آزمایشی در تابستان سال 1389 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه بیرجند انجام شد. آزمایش بصورت فاکتوریل در قالب طرح بلوک های کامل تصادفی با سه عامل شامل 1- تعداد لایه پلاستیک شفاف در سه سطح (شاهد بدون پوشش پلاستیک، یک لایه پلاستیک و دو لایه پلاستیک) 2- مدت زمان آفتاب دهی با سه سطح ( 15، 30 و 45 روز ) 3- عمق دفن بذر علف هرز علف پشمکی در چهار سطح (صفر، پنج، 10 و 15 سانتی متری خاک) در سه تکرار اجرا شد. نمونه های بذر به ترتیب پس از دوره های مختلف آفتاب دهی از اعماق مختلف خاک به آزمایشگاه منتقل شدند. بذرهایی که در مزرعه جوانه زده بودند شمارش، و آزمایش جوانه زنی سایر بذور در تمام تکرارها و تیمارها پس از آماده سازی در ژرمیناتور انجام شد. در طول دوره جوانه زنی، شاخص های همچون سرعت جوانه زنی، درصد زوال و درصد بذور جوانه زده اندازه گیری شدند. نتایج نشان داد آفتاب دهی خاک سبب افزایش قابل توجه دما (به میزان 3/6 تا 1/15 درجه سانتی گراد) نسبت به تیمار شاهد گردید. بیشترین درصد زوال بذور در تیمار دو لایه پلاستیک بدست آمد. درصد زوال بذر با طولانی تر شدن زمان آفتاب دهی افزایش، و با عمیق تر شدن دفن کاهش یافت. به طور کلی آفتاب دهی قابلیت جوانه زنی بذر علف هرز علف پشمکی را کاهش، و در نهایت باعث کنترل معنی دار آن شد. با توجه به نتایج این تحقیق آفتابدهی می تواند به عنوان یک روش کنترل غیرشیمیایی برای مهار علف هرز علف پشمکی به ویژه در نقاط گرم و خشک کشور به کار رود.
    کلیدواژگان: جوانه زنی، زوال بذر، کنترل غیرشیمیایی، مالچ
  • وحید سرابی، علی قنبری، محمدحسن راشد محصل، مهدی نصیری محلاتی، مهدی راستگو صفحات 21-28
    سولفونیل اوره ها علف کش هایی دومنظوره هستند، ولی خصوصیات باریک برگ کشی بیشتری نسبت به پهن برگ کشی دارند. از این رو، بهتر است این علف کش ها با دیگر علف کش های پهن برگ که جایگاه هدف متفاوتی دارند، مخلوط شوند. به منظور ارزیابی اثرات اختلاط علف کش نیکوسولفورون + ریم سولفورون با علف کش توفوردی + ام سی پی آدر کنترل علف هرز تاج خروس ریشه قرمز در مرحله رشدی چهار تا شش برگی کامل، آزمایشی در گلخانه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد در سال 1390 انجام شد. این آزمایش در قالب طرح بلوک های کامل تصادفی با هفت دز مختلف از علف کش ها در چهار تکرار به اجرا درآمد. نسبت های اختلاط بین دو علف کش از100:0، 5/12: 5/87، 25: 75، 50: 50، 75: 25، 5/12: 5/87 و 0:100 متغیر بود. نتایج پاسخ به دز منحنی ها در مخلوط علف کشی با کاهش 50 و 90 درصدی در وزن خشک علف هرز تاج خروس ریشه قرمز در مدل افزایشی دز مورد مقایسه قرار گرفت. نتایج نشان داد که اختلاط علف کش توفوردی + ام سی پی آبا علف کش نیکوسولفورون + ریم سولفورون نسبت به کاربرد هر یک از علف کش ها به تنهایی کنترل کمتری را روی علف هرز تاج خروس ریشه قرمز در پی دارد، بطوری که در اختلاط این دو علف کش تمامی مشاهدات صرف نظر از سطح پاسخ بیرون از خط آیزوبول قرار گرفتند و هم کاهی شدیدی بین دو علف کش اختلاط یافته مشاهده شد. از این رو، اختلاط علف کش توفوردی + ام سی پی آبا علف کش نیکوسولفورون + ریم سولفورون برای کنترل این گونه علف هرزی توصیه نمی شود، زیرا مقدار علف کش بیشتری را به محیط وارد می کند.
    کلیدواژگان: علف کش های گروه سولفونیل اوره، علف کش های گروه فنوکسی، علف هرز پهن برگ، مخلوط دوتایی، مدل افزایشی دز
  • سبحه غفارپور، سید عبدالرضا کاظمینی*، زینب سادات هاشمی، حبیب الله حمزه زرقانی صفحات 29-38
    به منظور مقایسه اثر سه علف کش سولفونیل اوره در مقادیر مختلف بر کنترل علف های هرز و عملکرد گندم در شرایط کاربرد بقایای گیاهی، آزمایشی به صورت اسپلیت پلات در قالب طرح بلوک های کامل تصادفی، با 4 تکرار در دانشگاه شیراز، انجام شد. فاکتور اصلی شامل نگهداری بقایای گندم و حذف بقایا و فاکتور فرعی شامل کاربرد علف کش های توتال، آپیروس و آتلانتیس هر کدام در دو مقدار توصیه شده و 30 درصد بیشتر از مقدار توصیه شده آنها و یک کرت بدون علف کش به عنوان شاهد بود. طبق نتایج بدست آمده وزن خشک علف های هرز در تیمار وجود بقایای گندم 1/41 درصد بیشتر از تیمار بدون بقایا بود. در مقایسه بین علف کش ها و مقدار مصرف آنها، علف کش توتال در دز افزوده بیشترین (4/58 درصد) و علف کش آتلانتیس در دز توصیه شده کمترین (3/19 درصد) میزان کنترل علف هرز را در مقایسه با تیمار شاهد (بدون علف کش) نشان داد. همچنین دز افزوده علف کش توتال موجب افزایش عملکرد دانه گندم از 88/3329 کیلوگرم در تیمار شاهد به 19/5283 کیلوگرم در هکتار شد و پس از آن دز توصیه شده توتال و دز افزوده آپیروس بیشترین عملکرد دانه گندم را نشان دادند. علف کش آتلانتیس نیز در دز توصیه شده کمترین (3/17 درصد) میزان افزایش عملکرد دانه را نسبت به تیمار شاهد سبب شد. به طور کلی بیشترین کنترل علف های هرز در تیمار برهمکنش کاربرد علف کش توتال در شرایط بدون بقایا بدست آمد و وزن خشک علف های هرز را 5/58 و 4/54 درصد نسبت به تیمار شاهد، به ترتیب در دز افزوده و توصیه شده، کاهش داد.
    کلیدواژگان: سولفوسولفورون، مت سولفورون، مزو سولفورون، مقدار علف کش، وزن خشک علف هرز
  • سیامک رحمانپور، علیرضا نبی بور، ابوالقاسم خدابنده صفحات 39-47
    بیماری زنگ آفتابگردان یکی از مهم ترین عوامل تهدید کننده این گیاه در نواحی مهم کشت در ایران بوده و منابع مقاومت به آن در ژرم پلاسم میزبان دست یافتنی می باشد. طی سال 1389 نمونه های برگ آفتابگردان آلوده به بیماری زنگ از استان های گلستان و آذر بایجان غربی جمع آوری شده و در مجموع هشت جدایه از این مناطق برای شناسایی نژادهای فیزیولوژیک روی رقم حساس رکورد مایه زنی گردیدند. سپس با روش تک پوستول کردن، عمل خالص سازی صورت گرفت. جدایه های قارچ پس از تولید انبوه در اتاقک های مجزای گلخانه بر روی سری نه تایی ارقام افتراقی آفتابگردان مایه زنی گردیدند. نتایج به دست آمده حاکی از تفاوت فیزیولوژیک جدایه های این دو منطقه و وجود دو نژاد مستقل می باشند. با توجه به تشابهات بیماری زایی روی لاین های افتراقی مشترک، نژادهای شماره 302 و 300 به ترتیب برای مناطق گلیداغ (گلستان) و خوی در استان آذربایجان غربی معرفی می شوند. بررسی های مقاومت ژرم پلاسم آفتابگردان به بیماری زنگ نیز در شرایط کنترل شده گلخانه صورت پذیرفت. این آزمایش ها با کاربرد روش مایه زنی گردپاشی با پودر تالک و استفاده از نژادهای شناسایی شده به اجرا در آمدند. نتایج حاصل نشان داد که هیبرید قاسم و لاین نگهدارنده باروری آن به نژاد 302 و هیبرید برزگر و لاین مربوطه آن به هر دو نژاد زنگ مقاوم هستند. از میان شش عدد تک بوته های مقاوم رقم گابور تنها ژنوتیپ G-445 در مقابل هر دو نژاد بیمارگر مقاومت داشت.
    کلیدواژگان: جدایه، ژنوتیپ، لاین های افتراقی، مقاومت، نژادهای فیزیولوژیک
  • موسی نجفی نیا، ایمان شهابی، سعید رضایی صفحات 49-57
    بیماری پوسیدگی ریشه و ساقه خیار ناشی از قارچ Fusarium oxysporum f. sp. radicis- cucumerinum یکی از بیماری های مهم و محدود کننده کشت خیار در دنیا و برخی مناطق ایران است. به منظور مطالعه و بررسی تنوع ژنتیکی این بیمارگر در منطقه جیرفت و کهنوج در سال های زراعی 1392 - 1389 تعداد 45 نمونه خیار دارای علائم به آزمایشگاه منتقل و اقدام به جداسازی بیمارگر گردید. تنوع ژنتیکی جدایه ها با استفاده از آزمون بیماری زایی، گروه های سازگاری رویشی و نشانگر ملکولی RAPD مورد بررسی قرار گرفت. اغلب جدایه های به دست آمده در این تحقیق قدرت بیماری زایی بالایی نشان دادند. در بررسی سازگاری رویشی، 288 جهش یافته نیت به دست آمد که 4/53% از جهش یافتگان نیت در کلاس فنوتیپی nit1، 2/25% در کلاس فنوتیپی nit 3 و 4/21% آن ها در کلاس فنوتیپی nit M قرار گرفتند. سه گروه سازگاری رویشی شناسایی و به صورت اختیاری VCG-B،VCG-A و VCG-C نام گذاری شدند. در مطالعات ملکولی، آغازگرهای تصادفی سری SBS با نشانگر مولکولی RAPD منجر به تکثیر باندهایی در گستره 250 تا 2500 جفت باز گردید. نتایج تجزیه خوشه ای، جدایه ها را در سطح تشابه 84 درصد در دو خوشه قرار داد که بیانگر تشابه ژنتیکی بالای جدایه ها است. این اولین مطالعه بررسی تنوع ژنتیکی در جدایه های قارچ Forc با استفاده از گروه های سازگار رویشی و نشانگر مولکولی RAPD در جمعیت های این گونه در ایران است.
    کلیدواژگان: پوسیدگی ریشه و ساقه، تنوع ژنتیکی، خیار، فوزاریوم
  • ابراهیم ایزدی دربندی، مهناز میرزایی، هادی مهدیخانی صفحات 59-69
    به منظور بررسی فلور وضعیت پراکنش علف های هرز باغ های پسته (Pistacia vera) شهرستان کرمان، تعداد 19 باغ از چهار بخش این شهرستان به طور تصادفی انتخاب و نمونه برداری علف های هرز با استفاده از کوآدرات 5/0× 5/0 متر مطابق الگوی W در سال 1393 انجام شد. سپس علف های هرز موجود در هر کوآدرات به تفکیک جنس و گونه شناسایی و تعداد علف های هرز هر گونه داخل کادر نیز شمارش شد. شاخص های فراوانی گونه، یکنواختی پراکنش، میانگین تراکم گونه و شاخص غالبیت به علاوه فراوانی نسبی، یکنواختی پراکنش نسبی، میانگین تراکم نسبی و شاخص غالبیت نسبی برای هر گونه محاسبه شدند. در نهایت جهت گروه بندی علف های هرز از روش تجزیه خوشه ایبه روش وارد و با استفاده از مربع فاصله اقلیدسی استفاده شد. در این تحقیق 57 گونه علف هرز از 18 خانواده گیاهی شناسایی شد که دو لپه ای ها با 45 گونه متنوع تر از گونه های تک لپه با 11 گونه بودند. پنج علف هرز جو موشی (Hordeum murinum L.)، پیچک صحرایی (Convolvulus arvensis L.)، تلخه (Acroptilon repense L.)، پنجه مرغی (Cynodon dactylon L.) و اسفناج وحشی (Atriplex sp.) به ترتیب بیشترین فراوانی را داشتند و با بیشترین شاخص غالبیت، مهم ترین علف های هرز باغ های پسته شهرستان کرمان شناخته شدند. تجزیه خوشه ایگونه های شناسایی شده را به چهار گروه تقسیم کرد که به ترتیب اهمیت از پایین به بالای دندروگرام قرار گرفتند. نتایج این تقسیم بندی شباهت زیادی به نتایج به دست آمده از بررسی شاخص های اندازه گیری شده داشت.
    کلیدواژگان: باغ پسته، تراکم، غنای گونه ای، فراوانی، شاخص غالبیت
  • صفرعلی صفوی صفحات 71-82
    زنگ زرد یکی از بیماری های مهم جو در بیشتر نواحی کشت این محصول در جهان بوده و در برخی سال ها در نتیجه همه گیری بیماری خسارت های شدیدی را موجب می شود. در ایران نیز این بیماری به دلیل کشت ارقام حساس و یا ظهور پاتوتیپ های جدید، در برخی نواحی کشور در حال گسترش است. در این پژوهش واکنش های گیاهچه ای و بالغ 29 رقم جو همراه با شاهد حساس ارزیابی شدند. واکنش گیاهچه ای در شرایط گلخانه ای با استفاده از پاتوتیپ های (PSH-51،PSH-74 ،PSH-85 وPSH-89) زنگ زرد جو و (6E150A+،Yr27) زنگ زرد گندم ارزیابی شد. واکنش بوته های بالغ نیز با دو بار آلودگی مصنوعی در شرایط مزرعه در طی سال زراعی 90-1389 با مایه زنی زادمایه زنگ زرد جو و گندم در حومه اردبیل انجام شد. نتایج ارزیابی واکنش ها نشان داد که سه رقم Emir، Asterix و ماکوئی در هر دو مرحله گیاهچه ای و بالغ نسبت به تمام پاتوتیپ ها مقاوم هستند. شش رقم در مرحله گیاهچه حداقل نسبت به پاتوتیپ PSH-85 مقاوم و در مرحله بلوغ حساسیت نشان دادند. سیزده رقم در مرحله گیاهچه حداقل نسبت به یک پاتوتیپ حساس و در مرحله بلوغ واکنش نیمه حساس تا نیمه مقاوم نشان دادند. ارقام مقاوم شناسایی شده می توانند به عنوان والد مقاوم در برنامه تولید ارقام مقاوم جو به این بیماری مورد استفاده قرار گیرند.
    کلیدواژگان: جو، زنگ زرد، پاتوتیپ ها، مقاومت گیاهچه ای، مقاومت گیاه کامل
  • محمدرضا بازیار، محمود عطارزاده، محمود دژم، غلامرضا نیک فرجام صفحات 83-90
    کاربرد مواد دگرآسیب در مدیریت علف‏هرز سودمند است و به همین دلیل توجه زیادی را در دو دهه‏ی اخیر به خود جلب کرده است. پس از جمع آوری نمونه هایی از برگ بنگرو، عملیات اسانس گیری در آزمایشگاه مرکز تحقیقات کشاورزی و منابع طبیعی شیراز صورت گرفت. سپس پتانسیل دگرآسیبی این اسانس بر جوانه زنی بذر و رشد گیاهچه های علف‏هرز پنیرک (Malva neglecta) و چاودار (Secale montanum) مورد بررسی قرار گرفت. این پژوهش به صورت فاکتوریل در قالب طرح کاملا تصادفی انجام گرفت. فاکتور اول شامل علف‏های ‏هرز پنیرک و چاودار و فاکتور دوم شامل غلظت های صفر، 250، 500، 1000 و 2000 میلی‏گرم در لیتر از اسانس برگ بنگرو بود. در این پژوهش، آنالیز اسانس برگ بنگرو به‏دست آمده به‏روش تقطیر با آب به وسیله کروماتوگرافی گازی و کروماتوگرافی گازی متصل به طیف‏سنج جرمی امکان شناسایی 53 ترکیب که در برگیرنده 91/98 درصد کل اسانس بود را فراهم ساخت. بیشترین جوانه‏زنی پنیرک و چاودار با میزان 6/87 درصد در شرایط بدون اسانس بنگرو (شاهد) و همچنین بیشترین سرعت جوانه‏زنی در پنیرک و چاودار به ترتیب با 9/10 و 1/12 بذر در روز در شرایط شاهد بدست آمد. با افزایش غلظت اسانس بنگرو، درصد و سرعت جوانه‏زنی در پنیرک و چاودار روند کاهشی را نشان داد، به‏طوری‏که کمترین درصد جوانه‏زنی در تیمار 2000 میلی‏گرم در لیتر بدست آمد. همچنین با افزایش غلظت اسانس درختچه بنگرو، سبب کاهش در میانگین وزن خشک پنیرک و چاودار شد. در مجموع، نتایج این پژوهش نشان داد که اسانس بنگرو دارای توان دگرآسیبی بالایی بر روی گیاهان پنیرک و چاودار است و علف هرز پنیرک حساسیت بیشتری نسبت به چاودار به اسانس بنگرو نشان داد.
    کلیدواژگان: شاخص بنیه گیاهچه، علف هرز، کروماتوگرافی گازی، وزن خشک گیاهچه
  • سمیه امینی، خدایار همتی، حسن نوروزی صفحات 91-99
    امروزه بدلیل ظهور علف های هرز مقاوم و ایجاد آلودگی های زیست محیطی، محققین به دنبال کاهش وابستگی کشاورزی به علف کش ها می باشند که یکی از جایگزین های مناسب در این زمینه، استفاده از گیاهان آللوپات است. هدف از تحقیق حاضر، غربال اولیه گیاهان از نظر ویژگی های دگرآسیبی می باشد. در این پژوهش، با استفاده از روش ساندویچ ویژگی های دگرآسیبی 55 گونه گیاهی (59 نمونه) متعلق به 27 خانواده، مورد بررسی قرار گرفت. روش ساندویچ، از جمله روش های جدید زیست سنجی گونه های گیاهی است که برای ارزیابی فعالیت ترکیبات سمی بقایای گیاهان به کار می رود. با این روش می توان تعداد زیادی گیاه را در مدت زمانی کوتاه و با حداقل نمونه گیاهی از نظر قابلیت آللوپاتی، ارزیابی کرد. نتایج نشان داد از بین گیاهان مورد بررسی، برگ گیاهان Mentha spicata، Nepeta cataria و Nepeta glomerulosa بیشترین اثر بازدارندگی را بر رشد ریشه چه و ساقه چه دانهال کاهو داشتند. همچنین، بقایای برگی گیاه Leptorhabdos parviflora و بذر گیاه Allium oschanini نیز اثرات دگرآسیبی نسبتا شدیدی را به صورت بازدارندگی رشد، نشان دادند. از گیاهان معرفی شده در این تحقیق می توان در راستای تحقق کشاورزی ارگانیک و تولید علف کش های با ماده موثره طبیعی استفاده کرد.
    کلیدواژگان: آللوپاتی، بازدارندگی رشد، ترکیبات ثانویه، گیاهان دارویی
  • اعظم حاتمی همپا، عبدالله جوانمرد، محمدتقی آل ابراهیم، امید سفالیان صفحات 101-119
    امروزه در سیستم کشاورزی پایدار استفاده از توانایی آللوپاتیک گیاهان به عنوان روشی سودمند در مدیریت علف های هرز پیشنهاد شده است. در همین راستا، به منظور ارزیابی عکس العمل گندم، چغندرقند، سلمه تره و تاج خروس به اثرات آللوپاتیک عصاره آبی اندام هوایی سورگوم و تلخه، آزمایشی به صورت فاکتوریل بر پایه طرح کاملا تصادفی با سه تکرار در گلخانه دانشکده کشاورزی دانشگاه مراغه در سال 1395 اجرا شد. تیمارها شامل عصاره آبی اندام هوایی تلخه و سورگوم و غلظت عصاره (شاهد، 5، 10 و 20 درصد حجمی) بودند. نتایج نشان داد وزن تر و خشک اندام هوایی و ریشه گندم، وزن تر و خشک ریشه سلمه تره تحت تاثیر ترکیب تیماری نوع عصاره با غلظت قرار گرفتند. در حالی که صفات رشدی چغندرقند و تاج خروس فقط تحت تاثیر غلظت عصاره واقع شدند. علاوه بر این، کاهش صفات رشدی تاج خروس با کاربرد عصاره آبی سورگوم بیشتر از عصاره تلخه بود. در حالی که اثر بازدارندگی عصاره آبی تلخه روی صفات رشدی گندم، چغندرقند و سلمه تره بیشتر از عصاره سورگوم بود. همچنین فعالیت آنزیم های پراکسیداز، کاتالاز و پلی فنل اکسیداز، غلظت پرولین و میزان قند محلول تحت تاثیر غلظت عصاره آبی سورگوم و تلخه قرار گرفتند، به طوری که با افزایش غلظت عصاره فعالیت آنزیم های آنتی اکسیدانت پراکسیداز، کاتالاز، پلیفنل اکسیداز و غلظت پرولین و قند محلول در همه گیاهان افزایش معنی داری پیدا کردند. بر اساس میانگین، کاربرد 20 درصد عصاره آبی تلخه و سورگوم فعالیت آنزیم های کاتالاز، پراکسیداز، پلی فنل اکسیداز و غلظت پرولین گیاهان را به ترتیب 85/100، 02/62، 94/24 و 61/143 درصد نسبت به شاهد (عدم مصرف عصاره) افزایش داد. براساس کاهش رشد گیاهچه و افزایش فعالیت آنزیم های آنتی اکسیدانت در این مطالعه می توان نتیجه گرفت که عصاره آبی سورگوم و تلخه می توانند به کنترل رشد علف های هرز به عنوان علفکش زیستی کمک نمایند.
    کلیدواژگان: پرولین، علف کش زیستی، غلظت عصاره، کاتالاز، کشاورزی پایدار
  • حدیث محمدی نوری، جهانشیر شاکرمی، شهریار جعفری، نرگس عینی صفحات 121-128
    مشکلات سموم تدخینی متداول شامل نگرانی های زیست محیطی، سمیت برای انسان، اثر روی موجودات غیر هدف، گسترش مقاومت آفات و هزینه بالا موجب تلاش برای دستیابی به روش های کم خطر و ارزان برای کنترل آفات انباری شده است .در این تحقیق سمیت تنفسی و بازدارندگی تخم ریزی پودر گیاهان بابونه، بومادران، آویشن، پونه، چویل، شبت، دارچین، ریحان و زنجبیل روی سوسک چهار نقطه ای حبوبات در شرایط دمایی 2±30 درجه سلسیوس، رطوبت نسبی 5±60 درصد و تاریکی انجام شد. هر ترکیب در پنج غلظت و پنج تکرار به همراه شاهد مورد بررسی قرار گرفت. غلظت ها با توجه به آزمایشات اولیه انجام شدند و برای ترکیبات مختلف متفاوت بودند. بر اساس نتایج، همه پودرهای گیاهی بطور معنی داری روی این آفت سمیت تنفسی و بازدارندگی تخم ریزی داشتند. پودر گیاه پونه بیش ترین تاثیر حشره کشی را روی این آفت داشت و در غلظت یک گرم بر لیتر موجب مرگ و میر 96 درصدی این آفت شد. بر اساس نتایج غلظت کشنده 50 درصد (LC50) پودر پونه، دارچین، زنجبیل و ریحان از نظر سمیت تنفسی به ترتیب 31/0، 47/2، 01/4 و 81/4 گرم بر لیتر هوا برآورد شد. پودر پونه، دارچین و زنجبیل در غلظت یک گرم بر لیتر به ترتیب 74/91، 25/90 و 08/90 درصد بازدارندگی تخمریزی داشت. به نظر می رسد پودر این گیاهان بخصوص پونه می تواند به عنوان آفت کش کم خطر و ارزان در مناطق روستایی توصیه شود.
    کلیدواژگان: آفت انباری، آفت کش گیاهی، بازدارندگی تخمریزی، سمیت تنفسی
  • مرجان اختلاط، بهزاد حبیب پور، معصومه ضیایی، لادن پورسرتیپ صفحات 129-137
    گونه های مختلف موریانه جنس Microcerotermes خسارت اقتصادی زیادی را به لوازم چوبی در ساختمان ها در کشور وارد می کنند. استفاده از طعمه های مسموم به عنوان یک روش بی خطر برای محیط زیست در کنترل موریانه های زیر زمینی پذیرفته شده است. مواد مختلفی جهت ساختن طعمه های جذاب برای موریانه های زیر زمینی مورد آزمایش قرار گرفته اند. در این تحقیق، واکنش تغذیه ای موریانه هدف به کاغذهای صافی (بسترهای سلولزی) تیمار شده با غلظت های مختلف ملاس (1 تا 6 درصد)، اوره (01/0 تا 1 درصد)، مخمر (01/0 تا 1 درصد) و روغن سویا (01/0 تا 10 درصد) در قالب آزمون های انتخابی و غیرانتخابی در چهار تکرار در شرایط آزمایشگاهی مورد ارزیابی قرار گرفت. برای نمونه شاهد از بسترهای سلولزی تیمار نشده (بدون مواد افزودنی) استفاده شد. بسترهای سلولزی هر تیمار به طور جداگانه درون ظروف پتری قرار گرفت و پس از مرطوب کردن با آب مقطر، تعداد 50 موریانه کارگر درآن قرار داده شد. واحدهای آزمایشی به مدت دو هفته در انکوباتور تاریک در دمای 2±28 درجه سلسیوس و رطوبت نسبی 5±90 درصد نگهداری و در این مدت مرگ و میر موریانه ها شمارش شدند. پس از پایان دوره آزمایش، کاهش وزن هر یک از بسترهای سلولزی مربوط به هر واحد آزمایشی تعیین شد. براساس نتایج بدست آمده از آزمون های انتخابی و غیرانتخابی، غلظت های مختلف ملاس و مخمر از لحاظ تاثیر بر زنده مانی موریانه اختلاف معنی داری با شاهد نشان ندادند اما از لحاظ تغذیه غلظت های 4 و 6 درصد ملاس بیشترین میزان تغذیه را داشتند و در مخمر نیز بیشترین میزان تغذیه را تیمار 1 درصد داشت. غلظت های مختلف اوره و روغن سویا از لحاظ زنده مانی و تغذیه اختلاف معنی داری با شاهد نشان ندادند. بنابراین از لحاظ تغذیه و زنده مانی غلظت های 4 درصد ملاس و 1 درصد مخمر انتخاب و جهت استفاده در تولید طعمه های سمی، جهت جلب هر چه بیشتر موریانه و مصرف بیشتر طعمه توسط آنها، پیشنهاد می گردد.
    کلیدواژگان: اوره، روغن سویا، طعمه موریانه، مخمر، ملاس
  • یاسر نیک پرست، رضا قربانی، حسین احمدزاده، قربانعلی اسدی صفحات 139-146
    عصاره گیاهان به عنوان یک کاهنده گیاهی برای تولید سبز، آسان، غیرسمی و دوستدار محیط زیست نانوذرات نقره مورد استفاده قرار گرفته است. در این مطالعه سنتز زیستی نانوذرات نقره با استفاده از عصاره برگ علف هرز تاج خروس ریشه قرمز Amaranthus retroflexus به عنوان کاهنده و پایدار کننده در سنتز نانوذرات نقره مورد استفاده قرار گرفت. تاثیر پارامترهای مختلف از جمله اسیدیته مخلوط واکنش، زمان تماس، نسبت عصاره به محلول نیترات نقره بر روی سنتز نانوذرات نقره مورد مطالعه قرار گرفت. تشکیل نانوذرات در داخل محلول نیترات نقره در ابتدا با استفاده از طیف نگاری در دامنه طول موج 200 تا 800 نانومتر توسط دستگاه طیف نگار UV–vis مورد تایید قرار گرفت. مورفولوژی نانوذرات تشکیل شده با استفاده از میکروسکوپ الکترونی عبوری مورد مطالعه قرار گرفت و نتایج نشان داد شکل نانوذرات کروی بوده و مونودیسپرس بوده و دامنه اندازه ذرات آن بین 2 تا 30 نانومتر بود. ساختار کریستالی نانوذرات به روش XRD مورد بررسی قرار گرفت و گروه های عاملی مسئول کاهش و پایدارسازی نانوذرات نقره با استفاده از طیف سنجی FT-IR مورد ارزیابی قرار گرفت. حداکثر سنتز نانوذرات در نسبت حجمی (v/v) عصاره به محلول نیترات نقره 1/0، 9=pH و مدت زمان واکنش 240 دقیقه مشاهده شد. بعد از تولید نانوذرات نقره زیستی، خاصیت ضدباکتریایی آن بر روی برخی پاتوژن های مقاوم انسانی؛ E. coli(Migula 1895) و Pseudomonas aeruginosa (Schröter 1872) و همچنین پاتوژن های مقاوم گیاهی Pseudomonas syringae(Van Hall، 1904) و Xanthomonas oryzae(Ishiyama 1922) مورد مطالعه قرار گرفت و با باکتری کش سیپروفلوکسازین مقایسه شد. نتایج مطالعه حاضر نشان داد که گیاه تاج خروس گزینه مناسبی برای تولید نانوذرات نقره بوده و نانوذرات تولید شده به این روش دارای خواص آنتی باکتریایی هستند. نانوذرات تولید شده دارای شکل کروی بوده و میانگین اندازه آنها 74/10 نانومتر بود که با نتایج حاصل از آنالیز XRD همخوانی داشت. نتایج FTIR نشان داد که آلکالوئیدها و سایر ترکیبات ثانویه گیاه مسئول اصلی سنتز نانوذرات هستند. پارامترهای مختلف مورد مطالعه بر سنتز نانوذرات تاثیرگذار بودند. محیط های قلیایی برای سنتز نانوذرات مناسب تر بوده و درصد عصاره به نیترات نقره 1/0 بهترین کارایی را داشت. تاثیر زمان بعد از 1 ساعت اختلاف معناداری نداشت.
    کلیدواژگان: آنتی باکتری، تولید زیستی، عصاره گیاهی، نانوذرات نقره
  • لیلا مطییان، مهدی نصراصفهانی، مجید اولیا صفحات 147-156
    چغندرقند Beta vulgaris L. از محصولات مهم صنعتی به شمار می‏آید. نماتد سیست، Heterodera schachtii از عوامل محدود کننده رشد این گیاه می‏باشد. در این تحقیق، مقاومت و ویژگی های آناتومیکی ریشه 70 ژنوتیپ چغندرقند نسبت به این نماتد مورد بررسی قرار گرفته است. ابتدا، میزان مقاومت ژنوتیپ‏های چغندرقند، بر اساس واکنش به نماتد سیست بررسی شد و بر اساس تعداد سیست تولید شده برای هر ژنوتیپ، در پنج طیف‏ مقاوم، نسبتا مقاوم، متحمل، نسبتا حساس و حساس قرار داده شدند. سپس، اجزای آناتومیکی ریشه، شامل ضخامت پریدرم و ضخامت لایه پارانشیم پوست، مورد بررسی قرار گرفت. نتایج نشان داد که پریدرم ژنوتیپ مقاوم 33 (SB32) با 27/536 میکرون، بیشترین ضخامت را داشته و سپس، دیگر ژنوتیپ‏های مقاوم 60 (F-20747)، 61 (F-20746)، 5 (SB31-HSF-2) و 3 (SB27-HSF-10)، به ترتیب با میانگین 480، 87/445، 436 و 47/419 میکرون قرار گرفتند. در صورتی‏که ژنوتیپ‏های حساس 23 (SB35-HSF-8)، 62 (F-20583) و 35 (SB35) به‏ترتیب با کمترین میانگین ضخامت پریدرم 13/194، 67/258 و 47/319 میکرون بودند. در ضخامت پارانشیم پوست، بیشترین مقدار در ژنوتیپ مقاوم 61 (F-20746) با 93/438 میکرون مشاهده شد و سپس، ژنوتیپ‏های مقاوم 3 (SB27-HSF-10)،60 (F-20747)، 62 (F-20583)، 29 ((7112*SB36)*S1-11) و 8 (SB31-HSF-7) به‏ترتیب، با میانگین 20/403، 40/402، 53/360، 27/344 و 73/323 میکرون قرار گرفتند. ژنوتیپ‏های حساس 19 (SB32-HSF-10) و 63 (F-20603) با میانگین ضخامت پارانشیم پوست 13/210 و 33/213 میکرون، کمترین ضخامت را دارا بودند. مابقی ژنوتیپ‏های مربوطه، در رابطه با صفات مذکور در طیف میانی این دو گروه مقاوم و حساس واقع شدند. این نتایج، موید یک رابطه مستقیم بین این صفات و میزان مقاومت برخی از ژنوتیپ‏های مورد بررسی به نماتد سیست چغندرقند، H. schachtii می باشد.
    کلیدواژگان: آناتومی ریشه، چغندرقند، نماتد مولد سیست، مقاومت
  • حسین حمامی، آرمین آزادی، رضا صدرآبادی صفحات 157-161
    به منظور بررسی اثرات دوره های پوسیدگی اندام های مختلف گیاه گوش بره بر رشد گیاهچه گوجه فرنگی آزمایشی به صورت فاکتوریل در قالب طرح کاملا تصادفی در 4 تکرار در سال 1393 در گلخانه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد اجرا شد. آزمایش دارای 2 عامل اندام های گوش بره در 4 سطح (ریشه، ساقه، برگ و گیاه کامل بدون گل آذین) و دوره های پوسیدگی در 8 سطح (0، 15، 30، 45، 60، 75 و 90 روز پوسیدگی و نیز شاهد) بود. نتایج نشان داد که دوره های پوسیدگی، نوع اندام و همچنین اثرات متقابل دوره های پوسیدگی و نوع اندام اثر معنی داری بر وزن خشک گوجه فرنگی داشتند. افزایش دوره پوسیدگی تا 45 روز منجر به کاهش وزن خشک گوجه فرنگی شد درحالی که با افزایش دوره پوسیدگی از 45 روزبه بعد افزایش تدریجی وزن خشک مشاهده شد. بیشترین شدت کاهش وزن خشک تولیدی مربوط به برگ های پوسیده بود.
    کلیدواژگان: برگ، دوره پوسیدگی، وزن خشک
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  • Ali Bagheri, Hamid Rahimian, Mostafa Oveisi Pages 1-9
    Introduction
    Weed management is an important agronomic practice. It would be takes 40% of time of small holder farmers, if carried out by hand. Farmers have being interested in more comprehensive programs for weed management that reduce weed populations over time and the use of reduced herbicide doses in order to diminish their production costs. Integrated weed management takes advantages of various methods to suppress weeds in a more common and environmental natural way. Today, it is understood that chemical herbicides are not free of problem. So researchers are working on integrated weed management, which brings all possible methods to control weeds. The use of reduced herbicide doses will cost a fraction of full dose and make them even more affordable to poor farmers who have a limited amount of resources. Researches indicate that there is good potential to reduce the number of herbicide applications and utilize lower herbicide doses within competitive cropping systems. Crop competitiveness advantage is a great potential for weed suppression that provides reducing herbicide dose to avoid its environmental and economic suffers. Therefore, a field experiment was conducted to evaluate the effect of reduced dose of imazethapyr on weed control when two bean cultivars grown in pure stand and intercropping together.
    Materials And Methods
    The field experiment was conducted as split plot based on randomized complete block design at the Research Farm of University of Tehran located in Karaj during 2013–2014. Main plots were five doses of imazethapyr (0, 25, 50, 75 and 100 percent of the recommended dose) and sub-plots comprised pure stands and intercropping of two bean cultivars include: Akhtar (the growth habit is upright) and Goli (the growth habit is creeping). Also there is a plot as weed free (control). When the plants were at the third trifoliate stage, determined doses of imazethapyr were sprayed. Weed dry weight and bean yield were analyzed by nonlinear regression. In order to obtain the response curves to the doses of imazethapyr, data were fitted by SigmaPlot software (version 11) according to the standard dose-response equation:Where W is the dependent variable, ED50 is equivalent to a dose of herbicide that reduces weed dry matter by 50 percent and b is the curve slope where the trend is linear. The yield data were fitted using a three-parameter logistic equation:where a is maximum yield, x0 represents a dose of herbicide in which the yield reaches 50 percent and b is the slope of the curve.
    Results And Discussion
    The community of weeds in the field mostly consisted of three species; Amaranthus retroflexus, Chenopodium album and Solanum nigrum that all are summer annual weeds. The dose-response model well described the effect of doses of herbicide on weed dry weight. Results indicated that weed species response to herbicide doses differently in bean cultivars and their intercropping. Among dominant weeds, A. retroflexus was determined high sensitive to increasing doses. Bean cultivars were solely different in competition with weeds, as creeping cultivar i.e. Goli with more competitive ability (like: fast early growth and area coverage) was more successful in weed suppression. Herbicide application at reduced dose could also be efficient when we used 75 percent of the recommended dose because led to a yield more than 4000 kg/ha in pure stand of Goli. Pure stand of Akhtar and intercropping showed yields of 3617 and 3641 kg/ha, respectively at 75 percent of the recommended dose. Relative yield total (RYT) for doses of 75 and 100 percent of the recommended dose and weed free control were 0.95, 0.87 and 1.03, respectively.
    Conclusion
    The results of experiment showed that weed sensitivity to herbicide doses vary differently by species. So that, A. retroflexus dry weight was more affected than C. album and S. nigrum in response to reduced doses of imazethapyr. The application of 25 percent of the recommended dose of this herbicide reduced A. retroflexus dry weight more than 50 percent. It seems that if the dominant weed in a field was the A. retroflexus, the farmer could greatly reduce dose of imazethapyr. However, usually weed community of fields are consisted of several species, therefore, to use reduced herbicide doses, sensitivity of all species should be considered. Also, using bean cultivars that potentially have high competitive ability, it could be a good supplement in combination with reduced doses of herbicide. In this experiment, Goli cultivar presented more potential to combine with reduced doses of imazethapyr.
    Keywords: Bean cultivars, Competition ability, Herbicide reduced doses, Intercropping
  • Seyed Esmail Ravangard, Seyed Vahid Eslami, Sohrab Mahmudi Pages 11-19
    Introduction
    Weeds are important components of agricultural ecosystems that compete with agricultural crops to capture resources and caused irreparable damage to the crops. By producing herbicides, a significant change was created in the management of weeds. But now days some new problems such as resistance of weeds to herbicides, loss of useful species and environmental pollutions have forced farmers to employ non-chemical weed management methods. An important non-chemical method for seed control of weeds is soil solarization, which has been used as a way for controlling weeds, pests and diseases. South Khorasan enjoys plenty of solar radiation during the summer which can be used as a useful tool for weed control.
    Materials And Methods
    To evaluate the effect of soil solarization on downy brome )Bromus tectorum L.( control, an experiment was conducted at the research farm of College of Agriculture, University of Birjand during the summer of 2010. The factorial experiment was performed as a randomized complete block design with three factors including the number of clear plastic layers (uncovered as the control, one-layer and two–layer plastic sheets(, duration of coverage (15, 30 and 45 days) and seed burial depth (0, 5, 10 and 15 cm) with three replications. Seeds were buried at different soil depths in the field and experimental plots were covered with the corresponding plastic layers. The seed samples alternatively were pulled out of different depths of soil and transported to the research laboratory. The seeds which were germinated in the field were counted, and the rest of them were incubated in a germinator set at 25/15°Cfor day/night. During the germination period, some index such as; germination rate, percentage of decayed and germinated seeds were measured. Tetrazolium test was used to examine the viability of not germinated seeds.
    Results And Discussion
    Results showed that solarization significantly increased soil temperature (as much as 6.3 to 15.1°C) compared to the control. The percentage of germination in the field decreased by increasing the layers of plastic coverage, as well asby increasing burial depths. The maximum percentage of decayed seeds were observed at two-layer plastic, one-layer plastic and control treatments, respectively. The percentage of decayed seeds increased by increasing solarization duration and it decreased by increasing burial depth. During the whole period of solarization, the lowest decay percentage was observed in the control treatment, while the greatest corresponding values were obtained from the seeds placed under oneand two-layer plastic sheets, indicating that accumulated temperatures under these sheets caused an increased decay percentage. At the soil surface and 5 cm burial depth, none of the downy brome seeds in 1- and 2-layer plastic sheet could germinate in the laboratory. It seems that the high temperatures generated by soil solarization have destroyed downy brome seeds under plastic covered treatments. A soil solarization period of 15 days was sufficient for destroying the seeds on the soil surface and those buried at 5 cm depth, while a solarization period of 45 days was required to destroy the seeds buried at 10 and 15 cm depths. Seeds that had been exposed to high temperatures caused by solarization for a longer period, had a lower germination rate. The greatest germination rate was observed in the control treatment and on the soil surface. The results of Tetrazolium test showed that all none germinated downy brome seeds which were subjected to Tetrazolium test had lost their viability, or in other words, were decayed. After finishing the solarization experiment we found that the concentration of sodium, calcium, and magnesium and sodium uptake ratio and soil pH decreased decreased under solarized plots. Moreover, electrical conductivity (EC) increased.
    Conclusion
    Overall, the results showed that solarization reduced the downy brome seed germinability and ultimately led to an effective method to control of this weed. It appears that solarization can be used as a non-chemical method for downy brome control especially in arid regions of the country. According to the results of this study, covering the soil with two-layer plastic sheet was the most effective and the best method of solarization.
    Keywords: Decayed seed, Germination, Mulch, Non-chemical control
  • Vahid Sarabi, Ali Ghanbari, Mohammad Hasan Rashed Mohassel, Mehdi Nassiri Mahallati, Mehdi Rastgoo Pages 21-28
    Introduction
    A few herbicides have been registered to control broadleaf weeds in Iran. Sulfonylureas are dual purpose herbicides to control narrow and broadleaf weeds, but these herbicides control narrow-leaf weeds better than broadleaf weeds. Hence, it is better to mix these herbicides with other broadleaf herbicides by different site of action to control broadleaf weeds effectively. Although the most of herbicide mixtures have been antagonism, but studies have shown that phenoxy herbicides have supplementary effects on broadleaf weeds in mixture with sulfonylureas.
    Materials And Methods
    In order to study the effect of nicosulfuron rimsulfuron (Ultima) in mixture with 2,4-D MCPA (U46 Combi Fluid) on redroot pigweed (Amaranthus retroflexus L.) at the four-to six-true leaf stage, an experiment was done in 2012 at the greenhouse of Agricultural Faculty of Ferdowsi University of Mashhad, Mashhad-Iran. Experiment was performed as a randomized complete block design with seven rates of herbicide mixtures and four replicates. The plants were sprayed using a greenhouse bench sprayer equipped by 8002 single nozzle with an even spray pattern delivering 200 L ha-1 at 300 kPa and boom height of 50 cm. Herbicides doses in mixture were considered based on effective dose required for 50% reduction in aboveground dry matter of redroot pigweed in pre-test experiments and joint action model calculations. ED50 doses of nicosulfuron rimsulfuron and 2,4-D MCPA applied alone were 22.33 and 55.98 g a.i. ha-1, respectively. The ratio of the herbicides in binary mixtures were 100:0, 87.5:12.5, 75:25, 50:50, 25:75, 12.5:87.5 and 0:100. The dose-response curves in binary fixed-ratio mixture were fitted simultaneously within each treatment using a three-parameter Gompertz model (with the lower limit equal to zero) available in the drc add-on package to the R programme. A Box-Cox transform-both-sides approach was performed to achieve variance homogeneity. The goodness-of-fit was assessed by graphical analyses of residuals and F-test for lack-of-fit. The results of dose-response curves of herbicides in mixture by 50 and 90 percent reduction in aboveground dry matter of redroot pigweed were plotted on the graph and compared to the ADM isobole. Points above the isoboles indicate that the joint action of a mixture is lower than predicted by ADM, while points below the isoboles indicate a joint action higher than predicted by ADM. In the present study, we examined whether the predicted ED50 and ED90 doses of the herbicide mixture was contained in the 95% confidence interval of the estimated ED50 and ED90 doses. This approach inevitably overestimates the number of significant deviations, because it does not incorporate a variation around the isobole. Significant deviations were termed antagonism if higher and synergism if lower than the corresponding estimated ED50 and ED90 doses. As the results with the herbicide mixtures originate from this experiment, it was necessary to standardize the x- and y-axes so that the ED50 and ED90 doses of the herbicides applied separately were always fixed to 1.
    Results And Discussion
    Results revealed that 2,4-D MCPA in mixture with nicosulfuron rimsulfuron has lower effect on redroot pigweed in comparison with where herbicides applied alone. So that all of observations were located outside of isobole line, irrespective of response level and strong antagonism was observed in mixture of two herbicides. Interference was observed more especially in mixtures that nicosulfuron rimsulfuron ratios was higher than or equal with 2,4-D MCPA. In these mixture ratios, observations were located far from isobole line at ED50 and ED90 response levels in comparison with higher mixture ratios of 2,4-D MCPA. There may be interference between two herbicides in mixture for absorption into and translocation to site of action. Herbicides formulation and adjuvants may be led to increase or decrease in efficiency of herbicides in mixture according to ADM. Studies have shown that formulation of one herbicide in mixture has important effect on active ingredient absorption of herbicides into the plants. Therefore, it is possible plants have had a chance to detoxify herbicide molecules in mixture at the same rates that herbicides applied alone. Hence, it was required higher rates in mixture to reach an effective dose at the site of action by 50 or 90 percent reduction in aboveground dry matter of redroot pigweed. Therefore, the efficiency of herbicides has been reduced in mixture compared to applied herbicides alone.
    Mixture of 2,4-D MCPA with nicosulfuron rimsulfuron does not recommend to control of this weed, because impose more herbicides rates to environment. Therefore, other binary mixtures must be evaluated using nicosulfuron rimsulfuron in mixture with synthetic phenoxy herbicides or other broadleaf herbicides.
    Keywords: Additive dose model, Binary mixtures, Broadleaved weeds, Phenoxy herbicides, Sulfonylurea herbicides
  • Sobhe Ghafarpour, Seyed Abdolreza Kazemeini*, Habiballah Hamzehzarghani, Zynab Alsadat Hashemi Pages 29-38
    Introduction
    Wheat (Triticum aestivum L.) is one of the most important crops among cereals. Many factors could be responsible for low yield in wheat, but one of the major causes is weed infestation. The efficacy of any herbicide primarily depends on selectivity and the dose of application. Use of herbicides is an effective and efficient means of weed management. In many cases, there are no practical alternatives to chemical weed control methods. However, not only all kinds of weeds do not control by one type of herbicide and continuous use of that, but also lead to increase weed resistance to herbicides over the time (Hall et al. 1999). Of the many weeds that infest wheat fields across southern Iran, wild barley (Hordeum spontaneum L.), foxtail (Setaria viridis L.) and wild oat (Avena fatua L.) are the major weeds causing economic losses .Baghestani et al. (2007) reported that sulfosulfuron at 19.95 and 24.90 g a.i. ha-1 were proper application rates for broadleaf and grass weed control in wheat fields. Sij et al. (2016) reported that sulfonylurea herbicides were more efficient in terms of weed control. Lair and Redente (2004) reported that sulfonylurea herbicide application increased stability and biomass of crop as much as 43% over auxin herbicide and simultaneously reduced the grass weeds up to 71%. Golparvar et al. (2012) reported that limited doses of herbicides provided the same yield as weed free plots, therefore, this could be recommended to the farmers. The present study initiated to investigate the effect of some sulfonylurea herbicides on weed control and grain and biological yield of winter wheat under with/without wheat residue treatments.
    Materials And Methods
    A field experiment was carried out in split-plot arrangement based on randomized complete block design with four replicates at College of Agriculture, Shiraz University, in 2014 growing season. Treatments included wheat residue at two levels (0 and 1850 kg/ha) as main plot in combination with each of the three of herbicides (Total, Apyrus and Atlantis) in two concentrations (recommended dose and 30% over the recommended dose) as Subplots. A weed infest plot (no herbicide application) was used as control. Wheat (Shiraz cultivar) planted on 5th November 2014, by Pneumatic planter at the rate of 200 kg ha-1 and maintaining 20 cm distance between crop rows. The plot size was 5m × 5m. Measurement of the effects included weed dry weight, weed density, wheat height, grain yield and its components. The data were subjected to the analysis of variance using SAS statistical software and means were compared by Duncan multiple range test (DMRT) at the 0.05 level of significance.
    Results And Discussion
    Investigation on the effects of different application doses of Total, Apyrus and Atlantis to control weeds in wheat fields under applied wheat residue showed that the wheat residue had negative effect on the efficiency of three types of herbicides and increased weed dry weight by 41.4 percent, as compared to without wheat residue. Wheat residue incorporated to soil, reduced biological yield (from 14865.60 to 12340.40 kg ha-1) in comparison to without residue treatment. Three herbicides reduced weed biomass and the highest (43.56%) and lowest (18.7%) weed control recorded compared to weedy check. In comparison to weed infest control, Total increased wheat grain yield (from 3329.88 to 5283.19 kg ha-1), followed by Apyrus and Atlantis with 46 and 21 % increase in wheat grain yield, respectively. Application of Total, Apyrus and Atlantis herbicides, had increased wheat biological yield in comparison with weed infest control by 30.7, 26.8 and 13.6 %, respectively. Additive dose of herbicides application had better effect on weeds control and increased wheat grain and biological yield more than the recommended dose. Baghestani et al. (2007) reported that the wheat yield increased with increasing application dose of herbicide without any crop injury. Wheat grain yield for Total applied at the recommended dose was 5090.99 kg ha-1 but no significant effect was observed when an additive dose of the Apyrus herbicide was applied. This could be due to strong weed control effect of the Total herbicide at this dose. Interaction effect of herbicides and application dose indicated that Total at additive dose resulted in highest seed yield and weed control. Wheat residue had negative effect on weed control and the highest weed dry weight (~48.5%) observed when Total was applied under no residue conditions.
    Conclusions
    All herbicide treatments increased wheat biological and grain yield as compared with the weed infested control. Application of Atlantis did not provide acceptable weed control in wheat. It is concluded that the most effective herbicide treatment was Total that provided maximum reduction in overall weed dry matter and obtained maximum grain yield. Atlantis had the lowest effect on weed control compared with the other herbicides (Total and Apyrus) and this could be due to poor weed control of the herbicide at both doses.
    Keywords: Dose, Mesosulfuronm metsulfuron, Sulfosulfuron, Weed dry weight
  • Siamak Rahmanpour Ozan, Alireza Nabipour, Abolghasem Khodabandeh Pages 39-47
    Introduction
    Sunflower rust is one of the most important diseases of the host in main cropping areas of Iran and resistance sources among the plant germplasm are accessible. Sunflower rust disease caused by Puccinia helianthi was reported first time at 1822 on collected samples from Eastern south areas of United States. It is considered as an important disease for sunflower cropping areas of South and North America, Argentina, Africa, India, China, and Australia and has been reported on the host worldwide. Incidence and severity of the disease on commercial hybrids had been increased up to early 1990s in Canada. Between 1988-89, the incidence on crop was reported up to 60 percent; whilst highly infected fields were appeared at the end of crop season. Puccinia helianthi has a worldwide distribution on sunflower and all species of Helianthus. There are also four other species which cause rust on cultivated and wild sunflowers. P. enceliae and P. masalis have been reported on wild sunflower and composites from southwest of United States. P. xanthi with a worldwide distribution on Xanthium Spp from Australia and Coleosporium helianthi from eastern areas of U.S. have been reported. Investigations reported some areas of Mazandaran and Golestan provinces showing infection including Behshahr, Kalaleh, Golidagh, Kalpoosh plain and Gonbad. Sunflower rust in Iran is considered as one of the important diseases which cause economic losses every few years. For instance, it caused 10 percent yield loss and 9.8 percent loss for oil yield. Genetic studies revealed that resistance is controlled by two dominant genes R1 and R2. By these identified genes, four physiological races of the pathogen became determinable. The presence of several resistant sunflower lines to rust with different origins reveals genetic variation for resistance to the disease. In this study, the variation of physiological races of sunflower rust was investigated to identify possible new races of the pathogen, Puccinia helianthi, and reaction of the host genotypes was also evaluated to the identified races.
    Materials And Methods
    Rust-infected leaf samples were collected from provinces Golestan and West Azarbayjan in 2010, and 8 isolates were inoculated on susceptible cultivar Record for physiological race identification purpose. Employing single pustule technique, the isolates were purified. The isolates after mass-production in separate chambers were inoculated on 9 standard differential lines. Inoculation and incubation methods were the same as for race identification procedure. The reaction of sunflower genotypes was evaluated by measuring pustule coverage percentage (PCP) according to computer-generated leaf diagrams depicting various percentages of leaf area covered with rust pustules. The interpreting resistance method proposed by Gulya and Masirevic (1995) was used in which three reaction patterns are defined as follows: immune (PCP= 0%), highly resistant (0.5%>PCP>0%) and susceptible (PCP.1%).
    Results And Discussion
    All collected isolates from the two main areas (i.e. Khoy and Golidagh) infected the non-resistant Perodovic cultivar indicating the pathogenicity of them. In addition, lines HA-335 and 803-1 were susceptible to all isolates. Lines RHA-265 and QHP1 demonstrated resistance to isolates collected from Golidagh, whereas the isolates of Khoy infected both lines. The results showed physiological differences between the main collection areas and presence of two dominant races. On the basis of pathogenicity similarities on common differential lines, races 302 and 300 were determined as dominant for Golidagh (Golestan) and Khoy (West Azarbayjan), respectively. Resistance evaluation of sunflower germplasm against rust disease was done under controlled greenhouse condition. The genotypes were tested by powdering the plants with mixture of the race's spore and Talc powder. The results demonstrated that 10 and 6 sunflower genotypes including hybrids Ghasem and Barzegar, their restorer lines and cultivar Gabor individuals were resistant against races 302 and 300, respectively.
    Conclusions
    Occurrence and distribution of physiological races of sunflower rust has importance in plant breeding research; as the process of breeding for resistant genotypes would be broken without considering the variation and distribution of the disease physiological races. In addition, genetic resistance to rust is controlled by dominant genes. Thus, access to new resistant sources in sunflower breeding is more likely. Among 23 lines and individuals of sunflower derived at the breeding processes, 16 resistant ones could help breeders to improve and release new hybrids or varieties containing resistance sources to the rust.
    Keywords: Differential Lines, Genotype, Isolate, Physiological Races, Resistance
  • Mousa Najafiniya, Iman Shahabi, Saeed Rezaee Pages 49-57
    Introduction
    Crops Production under greenhouse condition has been increased during the last decade in Iran. Two formae speciales of Fusarium oxysporum including F. oxysporum f.sp. radicis-cucumerinum (Forc), causing stem and root rot and F. oxysporum f.sp. cucumerinum (Foc) causing wilt in cucumber are the most important diseases of cucumber worldwide. Root and stem rot disease of cucumber caused by Forc is a very important disease of cucumber, recorded for the first time in Greece over 1989. Root and stem rot have been recorded on cucumber in Canada in 1994, in France in 1998, in China in 1999, and in Spain in 2000, causing significant yield losses. Using resistant varieties is the best and durable control method of this disease. Having knowledge on the variability and genetic diversity among the population of pathogen is necessary for screening cucumber cultivars to find resistant varieties. The objective of this research was to characterize the isolates of Forc causing stem and root rot of greenhouse cucumber in Jiroft region using pathogenicity test, vegetative compatibility groups and molecular marker assay.
    Material and
    Methods
    To study the genetic diversity among isolates of Fusarium on cucumber, many greenhouses were investigated for wilt, stem and root rot disease in Jiroft and Kahnuj, Kerman, Iran. Fusarium isolates were recovered from symptomatic cucumber plants during 2009-2011 growing season. The pathogenicity test, vegetative compatibility groups (VCGs) and RAPD marker were used to study the genetic diversity among isolates. Isolated fungi was inoculated on seedlings of commercial susceptible variety of cucumber (Negin) at four leaves stage and two different temperatures under greenhouse condition for separating two different mentioned Fusarium formae speciales. The Forc and Foc are, respectively, pathogenic at 17-21 oC and 25-30 oC. One to two weeks after inoculation, the results of pathogenicity tests were reported. Different plant species such as tomato, pepper, watermelon, melon, and cantaloupe were used to confirmed forma specialis of cucumber. To determine vegetative compatibility groups (VCGs), Fusarium Nit mutants were produced and complementation tests were carried out using Puhalla (1985) and Correll et al (1987) methods. RAPD primers series SBS was employed to study genetic diversity at molecular level.
    Results And Discussion
    Overall, 45 Fusarium isolates were recovered from infected cucumber. 42 isolates were identified as F. oxysporum and three isolates as Fusarium sp. Based on pathogenicity test, cultural and morphological characters, symptoms expression, experimental host range on some other plant species, 36 isolates were identified as F. oxysporum f. sp. radicis-cucumerinum and six isolates as F. oxysporum f. sp. cucumerinum. These cultural and morphological characteristics were similar to those of F. oxysporum. f.sp. radicis-cucumerinum described by Vakalounakis (1996) and later in other works (Punja& Parker, 2000; Cercauskas et al., 2001; Vatchev, 2007). Most of isolates showed high degree of disease severity index. Fusarium stem and root rot disease of greenhouse cucumber in Jiroft occuring mainly at bearing and harvesting time. A stripe shape stem lesion started from soil level and progress toward aerial parts. A whitish to pink/orange color due to mycelia mat and spore formation of Fusarium oxysporum on surface of stem were also observed. The causal fungal pathogen was easily isolated from infected roots, crown and stem. In total, 288 nit mutants were recovered from 36 isolates. Among these, 53.4% belonged to nit1, 25.2% to nit3, and 21.4% to NitM. Three VCGs groups were identified and arbitrary designated as VCG-A, VCG-B and VCG-C. PCR reactions were conducted using RAPD primers. High polymorphism among fungal isolates was found. The size of amplified bands ranged from 250 to 2500 bp. Cluster analysis of RAPD data using UPGMA method and Dice’s coefficient distinguished two main groups at 84% similarity level.
    Conclusions
    Our results showed that the F. oxysporum f. sp. radicis-cucumerinum is more prevalent forma specialis in greenhouse cucumber at Jiroft region. Due to difference among isolates of Forc in terms of aggressiveness and genetic diversity, it is proposed to use multigene resistant cultivars to achieve better control management. This work is the first attempt to assess genetic diversity among Fusarium isolates causing cucumber root and stem rot based on pathogenicity test, VCG and RAPD molecular markers in Kerman province, Iran.
    Keywords: Cucumber, Fusarium, Genetic diversity, Stem, root rot
  • Ebrahim Izadi-Darbandi, Mahnaz Mirzaei, Hadi Mehdikhani Pages 59-69
    Introduction
    Weeds movement and their dispersal power are amongst the major factors affecting the agricultural plants success. Diversity reflects the complexity of a system and can maintain its sustainability. Higher diversity results in higher inherent complexity of agro-ecosystems and strengthens their processes. It is necessary to realize the spatial distribution and temporal properties of the biodiversity components in agro-ecosystems, for the conservation and optimal utilization. Since weeds as a complementary component of agro-ecosystems are inseparable, studying species and their functional and structural diversity plays an important role in weed management and balance of ecological systems. Pistachio is one of the most economically important and strategic agricultural products in Iran. Weeds are one of the serious problems in pistachio orchards creating problems through competition, and costs imposed on farmers. Studying distribution and density of weed species can play an effective role in weed management. Therefore, this study was to assess the weeds flora and their distribution in pistachio orchards at Kerman city.
    Materials And Methods
    In order to investigate the flora and weeds distribution in pistachio (Pistacia vera) orchards of Kerman city, 19 orchards in 4 regions were selected. Weeds population sampling was conducted in a W pattern using 0.5×0.5 m² quadrates in 2014. The weeds at each quadrate were identified based on genus and species and the number of weed species was counted. Indices including frequency, uniformity of distribution, mean density, and abundance index as well as relative frequency, relative uniformity of distribution, relative mean density, and relative abundance were also calculated. Finally, weed species were classified based on cluster analysis using the Ward method and Euclidean distance square.
    Results And Discussion
    The weeds of pistachio orchards were belonged to 18 families and 57 species that dicotyledons with 45 species (78.95 percentage) had higher diversity than monocotyledons with 11 species (19.30 percentage). Family of Asteraceae with 12 weed species was the most abundant weed at Kerman’s pistachio orchards followed by Poaceae with 10 weed species, Chenopodiaceae with eight weed species and Fabaceae with seven weed species. According to the photosynthetic pathway, diversity of C3 weed species with 38 species (66.67 percentage) was more than twice of C4 weed species with 16 species (28.7 percentage). Based on life-cycle, diversity of annuals with 32 species (56.14 percentage) was more than perennials with 32 species (42.10 percentage). Five species of mouse barley (Hordeum murinum L.), field bindweed (Convolvulus arvensis L.), knapweed (Acroptilon repense L.), bermuda grass (Cynodon dactylon L.), and saltbush (Atriplex sp. L.) had the greatest frequency. The most important species of weeds with maximum abundance index were mouse barley, knapweed, saltbush, field bindweed, and bermuda grass. Based on cluster analysis, species were divided into four groups and based on importance were performed from the bottom to the top of the dendrogram.
    Conclusions
    Although the number of halophytic weeds in the pistachio orchards of Kerman was remarkable, the frequency and relative density of these weeds were not considerable. Identifying weed species, as well as their structural and functional diversity in pistachio orchards seems to improve the horticultural production management.
    Keywords: Abundance index, Density, Frequency, Pistachio orchards, Species richness
  • Safarali Safavi Pages 71-82
    Introduction
    Stripe (yellow) rust of barley (Hordeum vulgare L.), caused by Puccinia striiformis f. sp. hordei, is one of the most important diseases of barley in many parts of the world which can cause yield losses due to severe epidemics. Stripe rust of barley is become increasingly important in some parts of Iran due to the cultivation of susceptible cultivars and or appearing new pathotypes. Yield losses of 30 to 70 % occurred in these regions. New, more effective fungicides are available to control yellow rust, but the most efficient, economical, and environmentally friendly approach, is to grow resistant cultivars. It should be noted that the majority of designated Yr-genes are race-specific and therefore become ineffective in combating current pathogen populations due to development of new races. The average lifetime of the genes conferring race-specific resistance is estimated to be five years on the global basis. An alternative procedure for wheat breeders is the use of quantitative resistance. Two types of quantitative resistance, including high-temperature adult-plant (HTAP) resistance and slow rusting resistance, have been intensively investigated. Although several studies have been carried out for assessment of different barley genotypes to yellow rust in Iran, no research has been reported on the screening of barley cultivars for different pathotypes of barley and wheat yellow rusts.
    Materials And Methods
    In order to, resistance evaluation, seedling and adult plant reactions of 30 barley cultivars were evaluated to yellow rust. The seedling reaction was evaluated in a greenhouse using four barley pathotypes (PSH-51, PSH-84, PSH-85, and PSH-89) and one wheat pathotype (6E150A, Yr27). The seedling reactions were recorded under greenhouse conditions, based on a 0-to-9 scale. Race population was considered avirulent on the differential set when there were either no symptoms (IT 0) or there were necrotic or chlorotic flecks (IT 1), necrotic or chlorotic blotches without sporulation (IT 2), or necrotic or chlorotic blotches with only a trace to slight sporulation (IT 3 to 4). Race population was considered to be virulent if it caused moderate to abundant sporulation, with or without necrosis or chlorosis (IT 5, 6, 7, 8, or 9).
    Adult plant resistance was also evaluated by measuring final rust severity (FRS) and coefficient of infection (CI) under natural infection conditions with two times artificial inoculations. Artificial inoculation, during 2010-2011 cropping years, was carried out by barley and wheat yellow rust inoculum. Percent severity was recorded three times, starting when check reached 50% severity according to the modified Cobb,s scale, and reaction based on Roelfs et al. (1992). The coefficient of infection (CI) was calculated by multiplying disease severity (DS) and constant values of infection type (IT). The constant values for infection types were used based on; resistant (R) =0.1, moderately resistant (MR)=0.25, moderate or moderately resistant to moderately susceptible (M)=0.5, moderately susceptible (MS)=0.75, susceptible (S)=1.
    Results And Discussion
    Results of evaluations for resistance parameters showed that cultivars Eram, D10, Shori-5, Topper, Afzal, Goharjow and Torsh had susceptible reaction at seedling stage and the high values of FRS and CI, therefore were selected as susceptible cultivars. The cultivars Emir, Asterix and Makouee were resistant both at the seedling and adult plant stages, so they carry race-specific resistance genes against all used-pathotypes. Six cultivars showed resistant at seedling at least against pathotype PSH-85, but moderate or susceptible reactions at adult plant stage in Ardabil. The thirteen cultivars (entries; 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 26), was susceptible at the seedling at least against one pathotype, but had moderate (MR, M or MS) reactions at adult plant stages.
    Conclusions
    The results of the current study showed that the cultivars had a diversity of reactions, ranging from complete resistance to full susceptibility. Most of the evaluated cultivars exhibited moderate or low performance under high disease pressure shown by the susceptible check. The resistance of all categories (including complete resistance, to partial resistance) to stripe rust was observed. The cultivars having the low level of different parameters supposed to be having gene/s for varying degrees of slow rusting resistance or high-temperature adult-plant (HTAP) resistance. Cluster analysis of barley cultivars based on adult plant resistance parameters and seedling infection types revealed different groups/clusters which indicate considerable diversity for a level of resistance of these barley cultivars.
    Keywords: Adult plant resistance, Barley, Pathotypes, Puccinia striiformis, Seedling resistance
  • Mohammad Reza Baziar, Mahmood Attarzadeh, Mahmood Dejam, Gholamreza Nikfarjam Pages 83-90
    Introduction
    The role of allelopathy in weed management is useful and has attracted a lot of attention in the last two decades. The main goal of the allelopathic research is to find a reason for the interference of chemicals in natural circumstances and to introduce allelochemicals that affect the growth of other plant’s in farm or natural ecosystems. The other aim of this science is to identify and separate the plants allelochemicals. The prevention of weed growth by the crop allelopathy in the primary stages of establishment can reduce the need for commercial herbicides used at the beginning of the planting season. After that by increasing the competition, the crop can control the weed. The aim of this research is to identify the constituents of the leaf essence of Vitex pseudo-negundo and also to survey the allelopathic potential of different concentrations of the essence of Vitex pseudo-negundo in the prevention of the germination and the growth of Malva neglecta and Secale montanum weed bushes in the laboratory.
    Material and
    Methods
    The leaf samples of Vitex pseudo-negundo were collected from wild in Fasa, Fars province in 2016. To extract the essence, the leaves were collected and dried in the shade and then the essence was extracted. The extraction of the essence was done in the laboratory of the agricultural research and natural resources center of Shiraz. To analyze and survey the constituents of the essence, the gas chromatograph device with Flame Ionization detector and coupled chromatograph with mass spectrometer were used. In another part of this research, the potential of the allelopathy of the essence of the leaf of Vitex pseudo-negundo on the seed germination and the growth of Malva neglecta and Secale montanum were surveyed. This research was done in the form of factorial in the randomized complete block design with 4 repetitions in 2015. The first factorial included Malva neglecta and Secale montanum weeds and the second factorial included the essence of Vitex pseudo-negundo with the concentrations of 0, 250, 500, 1000, 200 ml. To analyze the data the statistical analysis software was used. To compare the means the Duncan test with 5 percent probability was used.
    Results And Discussion
    In this research, the analysis of the leaf essence of Vitex pseudo-negundo which was gained by distillation using gas chromatography and also gas chromatography attached to mass spectrometer made it possible to identify 53 compounds which constituted 98.91 percent of the essence. In this research, the essence of Vitex pseudo-negundo consisted of 37.743 percent Hydro carbonic monoterpenes, 28.865 percent Oxygen monoterpenes, 25.858 percent Sesquiterpene of Hydrocarbons, 6.32 percent Sesquiterpene Oxygen and 0.397 of other compounds. The most important constituents were α-Terpinyl acetate (22.007 percent) ¡ α-Pinene (16.378 percent))¡ E)-Caryophyllene (11.724 percent) and Limonene (8.68 percent). The highest percentage and rate of germination of Malva neglecta and Secale montanum were obtained in no essence condition of Vitex pseudo-negundo (control) with the increase of the essence concentration of Vitex pseudo-negundo, the percentage and rate of germination were decreased in Malva neglecta and Secale montanum so that lowest germination which was obtained in the treatment was 2000 ml. The length of the radical in Malva neglecta in the treatment was 1000 ml and the concentration of Vitex pseudo-negundo essence was 4.4 ml which showed a significant difference with 2000 ml treatment (2.2 ml). The length of the radical in Secale montanum in no essence condition of Vitex pseudo-negundo (control) showed a significant difference with 250 mg/l of the treatment Vitex pseudo-negundo. The shortest length of the radical of Secale montanum was 26.6 mm in average in the 2000 ml evidence of the essence of Vitex pseudo-negundo. The increase of the essence of Vitex pseudo-negundo caused the decrease of the wet weight average of Malva neglecta and Secale montanum. The other obtained results show that the wet weight of Malva neglecta with Secale montanum in different levels does not show any significant difference with Vitex pseudo-negundo when the concentrations are equal. The seed vigor index of Malva neglecta and Secale montanum were decreased with the increase of the essence concentration. The lowest seed vigor index was obtained in the essence concentration of 2000 mg/l. The highest seed vigor index in the no essence treatment of Vitex pseudo-negundo (control) in Malva neglecta and Secale montanum were 23.1 and 77.8 consecutively.
    Results
    The results of this research showed that the essential oil of Vitex pseudo-negundo has a high allelopathic ability on Malva neglecta and Secale montanum weeds. The Malva neglecta weed had a higher sensitivity to the concentration of the essential oil. There has been a widespread effort to the degree of inhibition increased with an increase in the concentration of the essential oil so that in all the measured characteristics, the highest prevention was observed at 2000 ml. In the present situation that there has been a widespread effort to improve the performance of the crops, knowing the allelopathic effects of the plants can be a great help in the suitable management of sustainable agriculture and weed control methods.
    Keywords: Gas chromatography, Seedling vigor index, Seedling dry weight, Weed
  • Somaye Amini, Khodayar Hemmati, Hasan Norouzi Pages 91-99
    Introduction
    Widespread use of herbicides in agriculture has led to loss of natural habitats, increase in pollution, generating herbicide-resistant weeds, risk of food poisoning and lower food quality. So new approaches are required in management, production, and utilization of the existing agricultural practices for sustainable agriculture. There are several techniques in this regard including allelopathy. Use of allelopathic compounds is a new approach for lowering undesirable effects of herbicides on the environment and fighting weeds resistant to herbicides. Recently allelopathy knowledge has been developed because of innovative methods and collaboration among scientists and achievements in suitable bioassays. Nowadays, old methods such as petri dishes or activated charcoal method have been replaced by new methods such as dish pack, sandwich, rhizosphere, and plant box. Researchers have indicated that many problems might be solved in allelopathy studies through these methods. Sandwich method is considered as one of the alternative methods for the old ones and is a very useful tool for screening the allelopathic effect of leaf litter under laboratory conditions. This method is a less time-consuming bioassay method and could be applied to screen more samples. Besides, allelopathic properties of many plants are evaluated using fewer plant samples through this method.
    Materials And Methods
    In this study, using a sandwich method, allelopathic properties of 55 plant species (59 samples) from 27 families were studied. The majority of plants were collected in 2016 from the different regions of South Khorasan province, Iran. The samples authenticated. Then, different parts of plants used for laboratory studies at Agricultural Researches Institute in Birjand University, Iran. Lettuce (Lactuca sativa L. var Great Lake 366) was used as an index because of its seeds sensitivity in chemical compounds, and allelopathic properties on the growth of seedlings of these lettuce varieties were evaluated. To investigate the allelopathic activity, an experiment was conducted as a completely randomized design with 3 replications. In order to assess the allelopathic activity of the selected plants, multi-dishes were used with 6 holes. Each hole had 3.5 cm diameter (Nunc Company, Japan). Ten milligrams of dried samples were placed in all three wells in the upper row and fifty milligrams was placed in rest of three lower wells of the six-well multi-dish plate. For the preparation of the growth medium, commercially available agar was applied. The medium was prepared as 0.5 % (w/v) and autoclaved at 115 °C for 20 min. 5 mL of autoclaved agar was added to each well of the multi-dish plate containing plant samples. After gelatinizing the agar within 30–45 min at room temperature, 5 mL agar was added again to all wells as the second layer and left at room temperature for gelatinized again. This made a sandwich of dried leaves by two layers of agar. Five lettuce seeds were put on the agar surface of the wells and all treatments were replicated three times. Each side of the prepared multi-dishes was then sealed by parafilm and wrapped in aluminum foil to protect them from light penetration and then were placed in an incubator (25°C). After 3 days, length of radicle and hypocotyl were recorded and monitored compared to control samples. Agar medium without plant samples was used as the control.
    Results And Discussion
    Growth of radicle and hypocotyl of lettuce seedling was present in the form of either inhibition (positive value) or promotion (negative value). The results showed that among the studied plants, Mentha spicata, Nepeta cataria, and Nepeta glomerulosa herbs highly affected growth inhibitory on radicle (96.4 %) and hypocotyl (94.8 %) of lettuce seedlings. Moreover, leaves of Leptorhabdus parviflora and Allium oschanini seeds strongly showed allelopathic effects by inhibiting the growth of radicle (91.0 %) and hypocotyl (85.2 %) of lettuce. Viola tricolor flowers plant had allelopathic effect as a deterrent growth only on radicle growth (90.0 %) and did not have significant effects on hypocotyl. In the current research, the introductory screening was done on 55 plants to recognize the suspected plants containing allelopathic compounds. However, further research is needed on these plants to figure out their effects on weeds.
    Conclusions
    The plants introduced in this research are mainly contain compounds such as Carvone, Limonene, α-Pinen, β-Pinen, 1,8 cineol, Thymol, Anethol, Camphor, Nepetalactone, β-caryophyllene and Geraniol. The results suggested that introduced plants may fulfill the organic farming and production of naturally originated herbicides. Therefore, more attention is needed for the future research focusing on finding the allelopathic responsible compounds by GC-MS and NMR techniques for using in organic agriculture. It is also necessary to investigate the ability of herbivorous of these compounds specifically.
    Keywords: Allelopathy, Inhibition of growth, Medicinal plants, Secondary metabolites
  • Azam Hatami Hampa, Abdollah Javanmard, Mohammad Taghi Alebrahim, Omid Sofalian Pages 101-119
    Introduction
    The continued use of synthetic herbicides has resulted in herbicide-resistant weeds as well as in negative impacts upon human health and the environment. Nowadays, agricultural techniques are focused on sustainable agricultural production. Allelopathy is defined as any direct or indirect positive or negative effect of one plant on the other plant species through the release of chemicals into the environment. It plays a significant role in agroecosystems, and affects the growth, quality and quantity of the produce. A number of plant species have been reported to have an allelopathic effect on other plant species. Allelochemicals produced by one crop species can influence the growth, productivity, and yield of other crops. Sorghum (Sorghum bicolor L.) is reported as one of the most allelopathic crops used extensively as cover and smother crops and is also incorporated into the soil for weed suppression. Russian knapweed (Acroptilon repens L.) has also been shown to produce phytotoxic compounds, which may contribute to its competitive behavior. Studies of the extract from Russian knapweed has suggested the presence of plant growth inhibitors.
    Material and
    Methods
    In order to evaluate the response of wheat (Triticum aestivum L.), sugar beet (Beta vulgaris L.), common lambsquarters (Chenopodium album L.) and redroot pigweed (Amaranthus retroflexus L.) to allelopathic effects of shoot aqueous extract of sorghum (Sorghum bicolor L.) and Russian knapweed (Acroptilon repens L.), a greenhouse experiment as factorial experiment based on randomized completely design with three replications was conducted in Faculty of Agriculture, University of Maragheh in 2016. The factors were included shoot aqueous extract of sorghum and Russian Knapweed and extract concentrations at 0 (distilled water as control), 5, 10 and 20% (m/v). In order to make the required aqueous extract, the maceration method was used according to the previously described method with some modifications. Briefly, the aerial parts of sorghum and Russian knapweed were dried under shade and powdered mechanically. For making the stock extract, 50, 100 and 200 g of the powdered plants were added to 1 l of distilled water and was placed in a closed container for 48 h with frequent agitation until the soluble matter was dissolved. The extract was filtered through Whatman filter paper. The concentration of the resulting extract was 5, 10 and 20% (v/v).
    Results And Discussion
    Seedlings growth was measured in terms of shoot fresh and dry weight and root fresh and dry weight. The lowest shoot dry and fresh weight were observed in 20% extract concentration of Russian knapweed and sorghum. Growth indices loss in redroot pigweed was greater with application of 20% extract of sorghum. However, growth loss in wheat, sugar beet and common lambsquarters was greater with application by extract of Russian knapweed. The results revealed that the sorghum and Russian knapweed aqueous extract had stimulatory effect on the proline content of the seedlings. Enhanced proline along with increase in water extract concentration suggests an allelochemical induced stress. Accumulation of proline indicates cellular damage in the target tissue caused by the ROS generated by peppermint allelochemicals. The present study concludes that peppermint allelochemicals induce oxidative stress in tomato through generation of ROS and upregulation of the activities of some scavenging enzymes. This result is in agreement with the findings of Batish et al. (8). They noted that proline enhances tolerance and provides protection against abiotic stress by avoiding ROS-induced damage to photosystems, membranes and proteins. Different concentrations of water extract had significant effect on the sugar contents of crops seedling. In comparison with the control, the sugar contents was generally increased in all treatments. Increase in sugar content is an indication of reduction in the activity of some respiratory enzymes and reduced consumption of sugar in low-growing plants. These results are in line with the findings of Abdulghader et al. (2008) where the level of soluble sugar in radish leaves was increased by heliotrope allelochemicals. In contrast, the soluble sugar content of seeds was reduced in the presence of the leaf litter leachates of some selected tree species. Our results showed that, by increasing concentration of the extract, there was an increase in the activity of antioxidant enzymes in the aerial parts of crops. This indicates that oxidative stress could play a role in phytotoxic phenomenon. Any increase in the activity of antioxidant enzymes demonstrates that sorghum and Russian knapweed water extract exposure causes excessive generation of O2-, resulting in oxidative stress. Increased activity of these scavenging enzymes can be due to the induction of secondary defensive mechanism against oxidative stress caused by sorghum and Russian knapweed allelochemicals. Allelochemicals absorbed by plant cells should be detoxified. The detoxification and the response of plant cells to it result in increased activity of antioxidant enzymes.
    Conclusion
    Application of aqueous extract of sorghum and Russian knapweed at 20% concentration increased the activity of catalase, peroxidase, polyphenol oxidase enzymes and proline concentration by 100.85, 62.02, 24.94 and 143.61%, respectively over control. On basis of the decrease in seedling growth and increase in activity of antioxidant enzymes, it could therefore, be concluded that sorghum and Russian Knapweed shoot aqueous extract as bioherbicide may help control growth of weeds.
    Keywords: Bioherbicide, Catalase, Extract concentration, Proline, Sustainable agriculture
  • Hadis Mohamadi Nori, Jahanshir Shakarami, Shahriar Jafari, Narges Eini Pages 121-128
    Introduction
    Insect pests of stored products are responsible for considerable economic losses to stored grains. In many storage systems, fumigants are the most economical and convenient tool for managing stored-grain pests not only for their ability to kill a broad spectrum of pests but also for their easy penetration into the commodity while leaving minimal residues. There are major setback to use the synthetic insecticides including the risk to the consumer, high cost of procurement, effects on non-targeted, as well as development of pest resistant strains and toxic residue in crops. Thus, there is an urgent need to develop economic, safe and environmental friendly fumigant alternatives. Recent studies has been indicated that plant secondary metabolites that may significantly affect plant resistance to parasites. Many researchers have studied insecticidal and oviposition deterrent effects of plant materials and have reported some compounds as appropriate agents in controlling pest infestation in stored products. In comparison with chemical pesticides, plant materials are less harmful not only to the environment but, in most cases, to humans and at times, may be used in treating human diseases as well. The present study was performed to evaluate the fumigant toxicity of dried leaf powders from nine medicinal plants against cowpea weevil, Callosobruchus maculatus (F.) (Coleoptera: Bruchidae).
    Materials And Methods
    The individuals of C. maculatus was obtained from laboratory stock cultures maintained in the Department of Plant Protection, Faculty of Agriculture, Lorestan University, Khorramabad, Iran. The beetles were reared on cowpea seeds and one to three- day- old male and female adults were used for bioassay tests.
    Plant materials: The fresh leaves of Chamaemelum nobilis L., Thymus serpyllum L. and Ferulago angulate (Schlecht) Boiss. were collected from Sephid Kouh in west Khorramabad. The aerial parts of Achillea millefolium L., and Mentha pulegium L. were collected from 30km north of Khoramabad and Anethum graveolens L. and Ocimum basilicum L. were collected from Serab-Changai farms, Khoramabad. Collected leaves were shadow dried under good ventilation and milled into fine powder using electric blender. Powders of two common spices, Cinnamomum zeylanicum Blume and Zingiber officinale Rosc were purchased from local market in Khorramabad.
    Inhalation toxicity- Tests: Fumigant toxicity of the botanical powders was tested against 1-3 days old adults of C. maculatus. 10 adults of C. maculatus was placed inside glass vials (volume: 100 ml) without considering the sex ratio. Since, according to the trial experiment, fumigant toxicity of the studied botanical powders significantly differed, therefore, different concentrations were prepared. This experiment was carried out in completely randomized design with five replicates incubated in the dark at 30±2°C and 65±5% RH. After 48 h of exposure period, the number of dead and live insects in each bottle was counted. Insects were considered whether they were dead if they could not move their appendages. Insect mortality percentage was calculated using the Abbott correction formula for natural mortality in untreated controls. Data were transformed to reduce variance heterogeneity. Data were analyzed using one-way analysis of variance followed by Duncan test to estimate statistical differences between means. Based on the mortality data obtained from different concentrations, LC50 values were determined using POLO-PC program.
    Oviposition deterrence was studied with two pairs of new adults beetles treated with different concentrations of botanical powders. After five days, number of eggs was recorded in treatments and control and oviposition deterrence was calculated as follows:Oviposition deterrence = (1–NEt / NEc)100
    Where: Nt = Number of eggs in treatment
    Nc = Number of eggs in control
    Results And Discussion
    Results showed that all the tested plant powders showed insecticidal and oviposition deterrent activity against C. maculatus. M. pulegium powder showed the strongest insecticidal activity against cowpea weeviland at the concentration of 1 g/lair caused 96% mortality of this pest. The LC50 values estimated for the plants, M. pulegium, C. zeylanicum, Z. officinal and O. basilicum were 0.31, 2.47, 4.01 and 4.81 g/lair, respectively. Powders of M. pulegium, Z. officinale and C. zeylanicum at concentration of 1 g/lair caused 91.74, 90.08 and 90.25% oviposition deterrent of C. maculatus, respectively. Overall, the powder of these plants, especially M. pulegium, could be recommended as low-risk and inexpensive pesticides in rural areas.
    Conclusion
    The results demonstrated that all the botanical powders exhibited insecticidal activity and oviposition deterrent against the C. maculatus. The results indicated that the powder of M. pulegium (LC50 = 0.34 μL/Lair) is the most toxic plant powder against C. maculatus.
    Keywords: Botanical pesticide, Oviposition detrerrency, Storage pest
  • Marjan Ekhtelat, Behzad Habibpour, Masumeh Ziaee, Ladan Poursartip Pages 129-137
    Introduction
    Termites are the common destructive pests of wood and cellulosic products in world-wide structures. In Iran, several Microcerotermes species regularly cause economic damages to wooden structures and building components in non-residential and residential areas. Microcerotermes diversus is a serious wood-destroying termite that exists in Khuzestan Province. This species has a broad scope of food foraging and also has the ability to create secondary communities within building walls and ceilings, as well as on trees. Eradication and control of this species by common methods such as the operation of drilling and injection of insecticides into the ground is faced with problems and in some cases is not always effectiveness. According to these problems, one of the effective methods of control is the use of baiting systems in which application of poisoned bait is an effectiveness control method for subterranean termites’ control. A variety of materials and toxicants have been tested to build suitable and attractive bait matrices against termites. The current research was carried out to produce a suitable formulation of toxic bait for control of subterranean termite M. diversus in Iran.
    Materials And Methods
    In this research, feeding responses of tested termite were evaluated to different cellulosic matrix substrates (filter papers) treated with different concentrations of molasses (ranging from 1 to 6%), urea (ranging from 0.01 to 1%), yeast (ranging from 0.01 to 1%) and soybean oil (ranging from 0.01 to 10%) additives. Non-treated filter papers were considered as control. Choice and no-choice laboratory tests were conducted. In no-choice tests, each matrix was treated with its assigned additive and allowed to be stabilized for 24hours before recording pre-trial weight. Each test matrix was separately placed in a Petri dish (9 cm in diameter) and wetted with distilled water prior to adding the termites. Then fifty termite workers were added to the Petri dishes. Experimental units were kept in a dark incubator (90±5%RH; 28±2°C) for two weeks, and termite mortality was periodically determined. The choice tests were performed following the same no-choice laboratory tests. Each experimental unit consisted of a 9cm plastic container connected to two other 9 cm plastic containers by a T-shaped tube. The central container included a mixture of soil and vermiculite (in the ratio of 2:1) moistened with distilled water, and a filter paper disc measuring 9 cm in diameter was plased in each two other plastic containers, one treated with selected concentrations of molasses, urea, yeast and soybean oil of no-choice tests and another with distilled water. Groups of foragers comprising 100 workers were placed in the central container. Experimental units were kept in a dark incubator (90±5%RH; 28±2°C) for two weeks. All experiments were conducted with four replicates. At the end of the trials, each test matrix (filter papers) was individually dried and weighed to determine feeding losses. Data analysis was done by SPSS software (version 16.0). Means were compared by Tukey̕̕ s test (no-choice test), and t-tests for two-sample paired (choice tests) (α=0.05).
    Results And Discussion
    The mean comparison of treatments with control through survival (after transformation the percentages to Arcsin ) showed that different concentrations of molasses and yeast did not had significant differences with compared to control. Also, there were not significant differences between soybean oil and urea and control, however 10% concentration of soybean oil and1% concentration of urea was significantly different compared with control and these two concentrations had lower survival compared with control. The mean comparison of treatments with control through feeding in no-choice test indicated that different concentrations of molasses and yeast had significant differences with control. By increasing the concentration of sugar in the molasses feeding rate is increased. Also with increasing concentration of yeast, the rate of feeding increased. The mean comparison of treatments with control through feeding showed that different concentrations of soybean oil and urea did not have significant differences with control, whereas 10% concentration of soybean oil was significantly different compared with control. With increasing concentration of soybean oil, the rate of feeding and survival of termites were greatly decreased. The mean comparison of treatments with control through feeding in choice test showed that selective concentrations of molasses (4%) and yeast (1%) had significant differences with control, but selective concentrations of urea (0.01%) and soybean oil (0.01%) did not had significant differences with control. These results confirmed the results of the no-choice test. Overall, matrices with 4% and 6% molasses concentrations and 1% yeast sustained the greatest feeding weight losses. Termite survival and matrix weight losses for different concentrations of urea and soybean oil were not significantly different with controls.
    Conclusions
    Adding of 4% molasses (w:w) and 1% yeast (w:w) to bait matrix is proposed to be used in a commercial production to increase consumption of toxic bait.
    Keywords: Feeding additives, Molasses yeast, Subterranean termite, Toxic bait
  • Y. Nikparast, Reza Ghorbani, Hossein Ahmadzadeh, Ghorbanali Asadi Pages 139-146
    Introduction
    Silver nanoparticles are important materials that have been studied extensively. They have unique physical, chemical and biological properties such as potential antibacterial activity. They can be synthesized by several physical, chemical methods. However, these methods are not environmentally friendly. Therefore, it is desirable to develop an eco-friendly method such as utilizing the biological species plant extracts for the synthesis of various environmental friendly metal nanoparticles. In addition, the integration of green chemistry principles into nanotechnology is essential. The biomolecules found in plants induce the reduction of Ag ions from silver nitrate to AgNPs. The process of reduction is extra cellular and fast leading to the development of easy biosynthesis of silver nanoparticle. The green synthesis of AgNPs using plants [6]–[11] have been before reported .Plant extract have been used as a natural reductant to produce green, non-toxic and environmentally friendly silver Nano particles.
    Materials And Methods
    to biosynthesis silver nanoparticles, Amaranthus retroflexus leaf extract was used as reductant and stabilizer agent. The effect of various parameters such as pH of the reaction solution, contact time, ratio of extract to silver nitrate solution on the synthesis of silver nanoparticles was studied. For reduction of silver ions, 1 mM silver nitrate was added to the weed leaves extracts with different ratio (v/v) of extract to silver nitrate with constant stirring under room temperature. The final nano-colloidal solution was subjected to repeat centrifugation (thrice) to get rid of any uninteracted biological molecules at 12,000 rpm for 15 min and the pellet were dried in vacuum oven. Formation of nanoparticles in the silver nitrate solution primarily was detected using UV-vis spectrometer (wavelength range 200 to 800 nm). The morphology of the nanoparticles studied using transmission electron microscopy. The crystalline structure of nanoparticles was studied by XRD and functional groups responsible for the reduction and stabilization of silver nanoparticles was evaluated using FT-IR spectroscopy. Pseudomonas aeruginosa was used as a sample bacteria for antibacterial studies. The antibacterial activity of AgNPs was investigated against gram negative drug resistant P. aeruginosa. For this reason, various concentrations of AgNPs from 400 to 1.56 µg/ml were incubated with cells of pathogenic bacteria in liquid medium. Growth of bacterial cells at the presence of AgNPs was compared with the growth of bacterial cells (positive control) in the absence of NPs. percentage of bacterial growth inhibition was evaluated at different AgNPs concentrations and MIC was determined against P. aeruginosa.
    Results
    The results of TEM showed that the nanoparticles were spherical and monodispersed with the particle size between 2 and 30 nm. The maximum nanoparticles synthesis occurs in silver nitrate to extract ratio (v / v) of 0.1, pH 9 and reaction time of 240 minutes. The FTIR result indicated the involvement of amides, carboxyl, amino groups and amino acid residues present in leaf extract in the NP synthesis. The XRD confirmed the structure of silver as a face-centered cubic structure [14]. Therefore, the XRD data clearly demonstrated the presence and crystal structure of the silver in the A. retroflexus leaf extract. Growth of bacterial cells was completely inhibited at the 200 µg/ml of AgNPs considered as the MIC. The antibacterial activity of AgNPs compared favorably with standard antibiotics including ciprofloxacin and cephtazidim. MIC of ciprofloxacin toward tested pathogen were 0.125 µg/ml which shows stronger antimicrobial activity in comparison with AgNPs. In contrast, only 50% of bacterial growth inhibition was observed at the 256 µg/ml of cephtazidim. Thus, the antibacterial activity of AgNPs was stronger than cephtazidim against P. aeruginosa. Leaves extract alone did not display any antimicrobial activity against tested microorganism.
    Conclusion
    AgNPs were successfully synthesized using Amaranthus retroflexus leaf extract as a reducing and capping agents. The structural, morphological and elemental studies of biologically synthesized AgNPs were characterized by UV-vis spectrometery, atomic absorption, XRD, FTIR, and TEM. The presence of AgNPs (200 µg/ml) was significantly reduced the cell viability of P. aeruginosa compared to control after 24 h incubation period. Biological synthesized silver nanoparticles could be of immense use in the medical field for their efficient antimicrobial function.
    Keywords: Antibacterial, Biosynthesis, Leaf extract, Nanoparticle
  • Leila Motieeian, Mehdi Nasresfahani, Majid Olia Pages 147-156
    Introduction
    Sugar beet cyst nematode (SBCN), Heterodera schachtii Schmidt 1871, marked as one of the most damaging disease of sugar beet worldwide. This is also an important disease pathogen of sugar beet which had an irreversible damage to this particular crop in Isfahan Province, Iran. Thus, the nematode - infested fields of sugarbeet in the province is to be threatened. This nematode has a wide host range, over 218 plant species from 95 genera, belonging to 23 families, including field crops, ornamentals and weeds as the hosts, which have been identified and introduced so far. The SBCN management's strategies are included as a long term crop rotation, use of catch crops, soil solarization, early planting and the use of nematicides. In general, the best method to control SBCN is use of resistant sugar beet cultivars.
    Materials And Methods
    In this study, the resistance and anatomical components of 70 sugar beet genotypes were screened against sugar beet cyst nematode (SBCN), Heterodera schachtii. Thus, the susceptibility of 70 sugar beet genotypes were assessed to sugar beet cyst nematode, H. schachtii in a completely randomized design in greenhouse and a complete randomized block design under the field conditions. The data were subjected to statistical analysis using SAS software and the means were compared using Duncan´s multiple test range. Cluster analysis was performed by the SPSS software. The initial population of SBCN in the infested soil was determined, before treating the selected field. Then, 200 g of soil were selected, out of which several samples collected from each plot and was air dried and in the file system, the cysts were extracted using Fenwick. Eggs and the second larvae in a 200 g of soil were calculated accordingly. Reproductive factors and the percent decrease and or increase in SBCN populations in each genotype were calculated relative to the initial population of the same treatment. Then, the comparison of means was done by Duncan tests. For the greenhouse experiments, the same treated soils from each treatment in field were poured into the clay pots with a capacity of 5 kg of soil. Initially, the genotypes based on sensitivity spectral to sugar beet cyst nematode were classified into 5 distinct groups of resistant, moderately resistant, tolerant, moderately susceptible and susceptible ones. Then, the root anatomical components of the sugar beet genotypes, such as the thickness of periderm, and skin parenchyma thickness were determined in microns.
    Results And Discussion
    The screening of sugar beet genotypes resulted in identifying the resistant and or susceptible ones to H. schachtii with a high significant difference under the field and greenhouse conditions. The combined results of greenhouse and field experiments coupled with cluster groups showed that, the genotypes 53 (SB-2), 69 (NE 0911), 16 (SB32-HSF-5) had the minimum number of cysts and the genotype of 16 (SB32-HSF-5) and 5 (SB31-HSF-2) had the lowest rates of eggs and larvae and reproductive factors. So, the two lines of 16 (SB32-HSF-5) and 5 (SB31-HSF-2), were identified as the most resistant genotypes and were located in the same cluster group in these studies. Therefore, it can be concluded that, these genotypes can be used as the nematode resistant genotypes and also, in breeding programs. The maximum thickness of the periderm was in the resistant genotype SB32 with 536.27 micron and was followed by resistant genotypes F-20747, F-20746, SB31-HSF-2, and SB27-HSF -10, with 480, 445.87, 436 and 419.47 microns respectively. The minimum thickness of the periderm was in susceptible genotypes SB35-HSF-8, F-20583 and SB35 with, 194.13, 258.67, and 319.47 microns, respectively. Also, the maximum thickness of the cortex parenchyma was in genotype F-20746 with 438.93 micron, followed by the genotypes 3 (SB27-HSF-10), 62 (F-20583), 29 ((7112 * SB36) * S1-11) and 8 (SB31-HSF-7) with 403.20, 402.40, 360.53, 344.27 and 323.73 microns, respectively. The minimum cortex parenchyma thickness was in susceptible genotypes SB32-HSF-10 and F-20603 with an average of 210.13 and 213.33 microns respectively. The other genotypes were located in between these two ranges. These results suggest a direct correlation coefficient between these characteristics of anatomical features and the resistance of some genotypes tested for the sugar beet cyst nematode disease.
    Conclusion
    1- It was found that, there are resistant genotypes among the tested sugar beet lines for cultivation and or breeding program.
    2- It also was found that, there is certain and direct correlation coefficient between the sugar beet root anatomical features and the resistance of some genotypes.
    3- The thickness of the periderm and cortex parenchyma as a physical barrier plays an important role in resistant of sugar beet to cyst nematode.
    Keywords: Cyst Nematode, Resistance, Root Anatomy, Sugar beet
  • Hossein Hammami, Armin Azadi, Reza Sadrabadi Pages 157-161
    Introduction
    Plants communicate and influence the growth of other plants (or even microorganisms) through excretion of certain chemical compounds (allelochemicals) which is known as allelopathy. A number of allelochemicals has been reported from different plant species. Allelochemicals include phenolic compounds, benzoxazinoids, sorgoleone, glucosinolates, terpenes, alkaloids, momilactones, and etc. Knowledge of the composition of allelopathic materials and weeds with allelopathic properties not only can reduce the negative impacts on crop yield production but also can be used to produce bio-herbicide by allelochemicals as active ingredient. Giradol (Chrozophora tinctoria L.) is an annual summer plant that belongs to Ephorbiaceae family. Giradol contains phenolic components including tannins, saponins (8), cumarins, phenylpropanoid glycosides (5) and flavonoids. Einhelling (2) reported that phenolic compounds are the most active compounds involved in allelopathy. Therefore, giradol has allelopathic characteristic. Giradol can be found in the wide range of fields in Khorasan Razavi. The abundant presence of phenolic compounds and giradol makes the study of giradol allelopathic effects on crops necessary in this region.
    Materials And Methods
    In order to evaluate allelopathic potential of giradol (Chrozophora tinctoria L.) organs on growth of tomato (Lycopersicon esculentum mill.), a study was conducted by using a completely randomized design (CRD) with factorial arrangement with four replications. This experiment was carried out in pots and consisted of organs at 4 levels (root, stem, leaf and total plant without inflorescence) and decay durations at 8 levels (0, 15, 30, 45, 60, 75 and 90 days decay and control). Samples of different organ plant of giradol were mixed separately with 3-liter pots with 1% m/m ratio. In order to apply decay period treatments, plant samples were added to the soil for 90 days of decay treatment. 15 days later, plant samples of 75 days of treatment were added to the required soil. The remaining treatments were applied at intervals of 15 days. Therefore, after 90 days, the soil was prepared for treatments of decay period (samples under the greenhouse condition at 28 °C / day and 20 °C per night during decay period). Then, the number of 10 Tomato seeds of falat cultivar were cultivated at the surface of soil in each pot. After 75 days (before flowering), the plants were harvested from the soil surface. The plant samples were oven-dried at 75 °C for 24 hours and weighed accurately by weight measuring tools with a precision of 0.0001 g. SAS 9.1 software was used for statistical analysis and Excel software for preparing graphs. Mean comparisons were performed with a protected LSD test at the level of 1%.
    Results And Discussion
    Analysis of variance of decay duration of giradol on dry weight of tomato showed the significant effects (p
    Conclusions
    The results revealed that decay duration and interactions between periods of decay and body type had a significant effect on tomato seedling dry matter. Our findings also demonstrated that selection of proper plant date can decrease allelopathic effects of residue giradol on tomato growth.
    Keywords: Decay duration, Dry weight, Leafy