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مطالعات حفاظت گیاهان - سال سی و یکم شماره 3 (پاییز 1396)

فصلنامه مطالعات حفاظت گیاهان
سال سی و یکم شماره 3 (پاییز 1396)

  • تاریخ انتشار: 1396/10/25
  • تعداد عناوین: 18
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  • علمی - پژوهشی
  • مهدی مهرابی کوشکی، مریم باورساد، رضا فرخی نژاد صفحات 362-373
    گونه های تریکودرما به فراوانی در خاک‏های کشاورزی یافت می‏شوند و اغلب آن‏ها بعنوان عامل بیوکنترلی علیه بیمارگرهای گیاهی عمل می‏کنند. آن‏ها همچنین بعنوان تولید‏کننده های صنعتی آنزیم‏ها شناخته می‏شوند. با توجه به اهمیت این قارچ، شناسائی صحیح آن‏ها در سطح گونه ضروری می‏باشد. شناسائی گونه ها مبتنی بر خصوصیات ریخت‏شناسی با توجه به هموپلاسی زیاد در صفات ظاهری مناسب نمی‏باشد. در این تحقیق، 40 جدایه‏ تریکودرما از استان‏های اصفهان، اراک و همدان با استفاده از توالی‏یابی جزئی ژن‏های nrRNA و tef1α شناسائی شد. جدایه ها در محیط PDB کشت شد و توده میسیلیومی با استفاده از کاغذ صافی جمع آوری شد. میسیلیوم‏ها در لیوفیلیزر خشک-‏انجمادی و سپس از آن استخراج DNA شد. واکنش زنجیره‏ای پلی‏مراز جهت تکثیر حدود 550 و 900 جفت باز بترتیب از نواحی ITS و tef1α با استفاده از آغازگر‏های عمومی و تخصصی انجام شد. قطعات تکثیری توالی‏یابی شد و بعد از ویراستاری و جستجو با استفاده از الگوریتم BLASTn، در بانک ژن ذخیره گردید. بر اساس صفات ریخت‏شناسی و آنالیز توالی های نوکلئوتیدی ITS و tef1α، جدایه ها در هفت گروه گونه‏ای شامل Trichoderma harzianum، T. capillare ، T. pleuroticola، T. asperellum، T. koningiopsis، T. brevicompactum و T. virens توزیع شدند. درخت فیلوژنتیکی این جدایه ها با استرین‏های مرجع تیپ بر اساس توالی tef1α ترسیم شد که در آن خوشه‏بندی فیلوژنتیکی تولید شده اصالت گونه‏ای جدایه های مورد بررسی را تایید کرد. این اولین گزارش گونه T. capillare برای میکوفلور ایران است.
    کلیدواژگان: DNA-بارکدینگ، خوشه بندی فیلوژنتیک، ریخت شناسی
  • علی اصغر چیت بند، رضا قربانی، محمدحسن راشدمحصل، محبوبه نبی زاده صفحات 374-387
    ارزیابی اثرات اختلاط مواد شیمیایی می تواند براساس مفاهیم مختلف سمیت شناسی، داروشناسی و کنترل علف های هرز انجام گیرد. به منظور پیش بینی اثرات افزایشی، هم افزایی و یا هم کاهی اختلاط دو به دو مخلوط علفکشی دس مدیفام+ فن مدیفام+ اتوفومیست، کلریدازون و کلوپیرالید روی علف های هرز تاج ریزی سیاه و تاج خروس ریشه قرمز، دو آزمایش بصورت دز- پاسخ در گلخانه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد در قالب طرح کاملا تصادفی با 105 تیمار در سال 1392 به اجرا درآمدند. تیمارهای آزمایش شامل هفت دز خالص و مخلوط از علف کش های فوق با پنج نسبت اختلاط 100:0، 75:25، 50:50، 25:75 و 0:100 بودند و برای هر یک از اختلاط ها سه تیمار شاهد در نظر گرفته شد. نتایج آزمایش نشان داد که اختلاط علف کش دس مدیفام + فن مدیفام + اتوفومیست با علف کش کلوپیرالید روی علف هرز تاج ریزی سیاه از حالت هم افزایی و در مورد علف هرز تاج خروس ریشه قرمز بیشتر از حالت هم افزایی تبعیت کرد. اختلاط علف کش کلریدازون با علف کش کلوپیرالید بر روی هر دو علف هرز بیشتر از حالت هم کاهی تبعیت کرد، بطوری که شدت اثرات هم کاهی در تاج خروس ریشه قرمز بیشتر از تاج ریزی سیاه بود. همچنین، اثرات اختلاط علف کش دس مدیفام + فن مدیفام + اتوفومیست با کلریدازون روی علف هرز تاج ریزی سیاه بیشتر از حالت افزایشی و در مورد تاج خروس ریشه قرمز بیشتر از حالت هم کاهی تبعیت کرد. کاهش کارایی اختلاط های علف کشی می تواند به دلیل محدودیت در جذب و انتقال علف کش ها باشد.
    کلیدواژگان: اختلاط علف کش ها، اثر افزایشی، مدل دز افزایشی، هم افزایی، هم کاهی
  • عباس عباسیان، قربانعلی اسدی، رضا قربانی صفحات 388-395
    به منظور ارزیابی تحمل گیاه مهاجم گل گندم به تنش یخ زدگی مطالعه ی به صورت طرح کاملا تصادفی با پنج تکرار درگلخانه تحقیقاتی علف های هرز دانشکده کشاورزی دانشگاه فردوسی مشهد در سال 1393 اجرا گردید. گیاه مهاجم گل گندم در معرض 7 دمای یخ زدگی (0 ، 3-، 6-، 9-، 12-، 15- و 18- درجه سانتی گراد) قرار گرفتند. گیاهان در محیط طبیعی نگهداری شده و پس از گذرانیدن دوره خوسرمایی از اول آبان 1392 تا 30 آذر 1393، با استفاده از فریز ترموگرادیان، تحت تیمارهای یخ زدگی قرار گرفتند. میزان پایداری غشاء سیتوپلاسمی گل گندم مورد مطالعه با استفاده ازآزمون نشت الکترولیت ها مورد ارزیابی قرار گرفت، سپس دمای کشنده 50 درصد نمونه ها بر اساس درصد نشت الکترولیت ها (LT50el) تعیین گردید. درصد بقاء نیز با شمارش تعداد بوته زنده در هر گلدان مورد ارزیابی قرار گرفت. سپس دمای کشنده برای 50 درصد بقاء (LT50su) و دمای کاهنده 50 درصد وزن خشک (RDMT50) در پایان دوره بازیافت (سه هفته بعد از اعمال تیمار یخ زدگی) تعیین شد. نتایج نشان داد کاهش دما ازC° 12- به C° 15- سبب افزایش معنی دار (05/0 P≤) نشت الکترولیت ها در گل گندم شد. همچنین کاهش دما از °C 9- به °C 12- سبب کاهش معنی دار (05/0 P≤) درصد بقاء و زیست توده گل گندم شد. در آزمایش حاضر LT50el، LT50suو RDMT50 گل گندم خوسرمایی شده با شرایط پاییزه به ترتیب C° 2/13-، C° 6/12- و C° 8/11- بود.
    کلیدواژگان: خوسرمایی، درصد بقاء، دمای کاهنده 50 درصد بقاء، دمای کاهنده 50 درصد زیست توده، دمای کاهنده 50 درصد نشت الکترولیت ها
  • حبیبه سلطانی، علی قنبری، مهدی راستگو، قربانعلی اسدی صفحات 396-408
    با هدف تاثیرگذاری تاریخ کاشت و تراکم کاشت بر شاخص های رشد و ارزیابی توانایی رقابتی سویا رقم ویلیامز با علف های هرز، آزمایشی در سال زراعی 1392 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد در قالب اسپلیت-اسپلیت و طرح پایه بلوک های کامل تصادفی به اجرا درآمد. تیمارهای این آزمایش شامل تاریخ کاشت به عنوان عامل اصلی (28 فروردین، 22 اردیبهشت، 16 خرداد) و تراکم کاشت به عنوان عامل فرعی (30، 40، 50، 60 بوته در متر مربع) و مدیریت علف های هرز به عنوان عامل فرعی-فرعی (کنترل و عدم کنترل علف های هرز) بود. نتایج نشان داد تاریخ کاشت 22 اردیبهشت، نسبت به تاریخ کاشت زودهنگام و تاریخ کاشت تاخیری شاخص سطح برگ، ماده خشک و سرعت رشد بیشتری حاصل کرد. در تراکم های بیشتر و تاریخ کشت های دیرتر، ماده خشک و شاخص سطح برگ بیشتری تولید شد. در شرایط حضور علف هرز با افزایش تراکم سویا از 30 به 60 بوته در متر مربع، میزان شاخص سطح برگ و ماده خشک افزایش یافت. تفاوت قابل ملاحظه ای بین ماده خشک تجمعی، شاخص سطح برگ، سرعت رشد محصول و آهنگ رشد در شرایط تداخل علف های هرز (تمام فصل) نسبت به کنترل علف های هرز وجود داشت. نتایج نشان داد که تاریخ کاشت 22 اردیبهشت و تراکم 40 بوته در متر مربع علاوه بر بهبود شاخص های رشد، سبب افزایش توان رقابتی سویا در مقابل علف های هرز می-شود.
    کلیدواژگان: آهنگ رشد، تداخل، سرعت رشد محصول، شاخص سطح برگ، عملکرد دانه
  • مجید عباس پور صفحات 409-419
    در این آزمایش به منظور بررسی امکان کنترل شیمیایی علف های هرز در مزارع زعفران، کارآیی علف کش های متری بیوزین (سنکور®) (5/562 گرم ماده موثره در هکتار)، مت سولفورون متیل + سولفوسولفورون (توتال®) (32 گرم ماده موثره در هکتار)، سولفوسولفورون (آپیروس®) (95/19 گرم ماده موثره در هکتار)، مزوسولفورون + یدوسولفورون + دی فلوفنیکان (اوتلو®) (96 گرم ماده موثره در هکتار)، تریاسولفورون + دایکامبا (لنتور®) (5/115 گرم ماده موثره در هکتار)، بن سولفورون متیل (لونداکس®) (30 گرم ماده موثره در هکتار)، اگزادیازون (رونستار®) (240 گرم ماده موثره در هکتار)، اکسی فلوروفن (گل®) (480 گرم ماده موثره در هکتار)، آترازین (گزاپریم®) (800 گرم ماده موثره در هکتار)، نیکوسولفورون (کروز®) (60 گرم ماده موثره در هکتار)، بروموکسینیل + ام سی پی آ(برومایسید®) (600 گرم ماده موثره در هکتار)، تری بنورون متیل (گرانستار®) (15 گرم ماده موثره در هکتار)، توفوردی + ام سی پی آ(یو 46 کمبی فلویید®) (5/1012 گرم ماده موثره در هکتار)، هالوکسی فوپ متیل (گالانت سوپر®) (108 گرم ماده موثره در هکتار)، بنتازون (بازاگران®) (1440 گرم ماده موثره در هکتار)، شاهد وجین دستی و شاهد بدون وجین مورد ارزیابی قرار گرفت. آزمایش در قالب طرح بلوک های کامل تصادفی با سه تکرار در مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی خراسان رضوی در مشهد در سال زراعی 94-1393 اجرا شد. علف های هرز غالب مزرعه خارلته، تلخه و چمن وحشی بودند. نتایج نشان داد تمامی علف کش های مورد بررسی باعث کاهش معنی دار تراکم و وزن خشک علف های هرز نسبت به شاهد بدون مبارزه شدند. در این میان، کارآیی علف کش متری بیوزین در کنترل علف های هرز بسیار مناسب بود بطوری که تراکم و وزن خشک علف های هرز در تیمار متری بیوزین کاملا مشابه تیمار شاهد وجین دستی بود. کاربرد علف کش متری بیوزین در پاییز بلافاصله پس از برداشت گل، و علف کش های هالوکسی فوپ متیل، بنتازون، اکسی فلوروفن، اکسادیازون، بن سولفورون متیل، آترازین و تریاسولفورون + دایکمبا در اوایل رویش علف های هرز در بهار ضمن کنترل مناسب علف های هرز باعث کاهش معنی دار تعداد و یا وزن تر گل زعفران نشدند و بنابراین به نظر می رسد امکان مصرف آنها در مزارع زعفران وجود دارد.
    کلیدواژگان: انتخاب علف کش ها، خسارت علف کش ها، عملکرد گل، کلاله، متری بیوزین
  • محمدرضا زرگران، محمد جمشیدی، سید رستم موسوی میرکلا صفحات 420-432
    یکی از عوامل اصلی تخریب جنگل های بلوط، جوانه خوار بلوط .Tortrix viridana L است و خسارت زیادی را به این جنگل ها وارد می سازد. هدف اصلی از انجام این تحقیق، بررسی تغییرات جمعیتی این آفت طی دو سال مختلف و عوامل تاثیرگذار بر آن به منظور تعیین راهکار های مناسب کنترل آفت بود. این تحقیق طی سال های 93 و 94 در منطقه قبرحسین با مساحتی در حدود 250 هکتار انجام شد و در چهار جهت جغرافیایی اصلی (شمال، شرق، جنوب و غربی)، ترانسکت هایی با فواصل 100 متری پیاده شد. در مجموع، در هر جهت تعداد 30 درخت دارمازو Quercus infectoria و تعداد 30 درخت وی ول Q. libani که از لحاظ شکل ظاهری مشابه بودند (جهت کاهش خطای نمونه برداری) در هر چهار جهت جغرافیایی اصلی مورد اندازه گیری قرار گرفتند. در هر درخت نیز چهار شاخه انتخاب (هر جهت یک شاخه به طول 50 سانتی متر) و در هر شاخه از نوک شاخه به سمت داخل، لاروهای آفت شمارش گردید. در هر دو سال، تعداد لاروهای جوانه خوار بلوط روی دارمازو بیشتر از وی ول بود. تعداد لاروهای جوانه خوار بلوط در هر دو گونه بلوط دارمازو و وی ول در سال 94 نسبت به سال قبل افزایش چشم گیری داشته است که ممکن است با افزایش دما مرتبط باشد. بررسی فراوانی جمعیت لاروهای جوانه خوار بلوط در جهت های جغرافیایی نشان داد برای هر دو گونه دارمازو و وی ول در سال 93 بیشترین و کمترین تعداد لارو به ترتیب در جهت جغرافیایی شرقی و غربی و در سال 94 نیز بیشترین و کمترین میزان فراوانی لاروها به ترتیب در جهت جغرافیایی جنوبی و شمالی بود.
    کلیدواژگان: آفت، انبوهی، جنگل، خسارت
  • مهدی مجاب، مجتبی حسینی، مجید کریمیان کلیشادرخی صفحات 433-444
    قیاق یکی از مهمترین علف های هرز مسئله ساز در دنیا است. پاسخ جوانه زنی و سبز شدن آن به فاکتورهای مختلف محیطی در شرایط آزمایشگاه و گلخانه مورد ارزیابی قرار گرفت. نتایج نشان داد که، خیساندن بذور به مدت 30 دقیقه در اسید سولفوریک غلیظ (98-95 درصد) بهترین تیمار برای شکستن خواب بذر می باشد. پاسخ جوانه زنی در دو رژیم نوری (روشنایی/تاریکی و تاریکی مداوم) همراه با دامنه دمایی متفاوت ( ثابت و متناوب) یکسان بود. این گیاه در دماهای متناوب 15/25، 20/30 و 25/35 در هر دو رژیم نوری بیش از 95 درصد جوانه زنی داشته است. در دمای ثابت نیز روند درصد نهایی جوانه زنی مشابه دماهای متناوب بود و این صفت در محدوده ی دماهای ثابت 25 تا 45 بیش از 90 درصد جوانه زنی داشت. نتایج آزمایش شوری و خشکی نشان داد این گونه به شوری و خشکی مقاوم است؛ به طوری که، پتانسیل اسمزی و ماتریک لازم جهت کاهش حداکثر 50 درصد جوانه زنی بر اساس برازش مدل لجستیک سه پارامتری به ترتیب 62/9- و 13/9- بار محاسبه گردید. با افزایش عمق کاشت ظهور دانه رست به طور معنی داری کاهش یافت. بر اساس مدل برازش داده شده عمقی که باعث کاهش 50 درصد حداکثر سبزشدن دانه رست می شود 86/5 سانتی متر تعیین گردید.
    کلیدواژگان: پتانسیل اسمزی، پتانسیل ماتریک، درجه حرارت، عمق دفن، نور
  • محمد حاجیان شهری، ابراهیم گنجی مقدم، حمید افضلی صفحات 445-455
    محلب پایه مهمی برای گیلاس و آلبالو محسوب می شود. این پایه در خاک های سبک ، آهکی ، سنگلاخی از سازگاری خوبی برخوردار است . اما به پوسیدگی ریشه ناشی از فیتوفتورا حساس می باشد. لذا این تحقیق با هدف ارزیابی عکس العمل 30 ژنوتیپ پاکوتاه گزینش شده محلب به بیماری پوسیدگی طوقه و ریشه ناشی از چهار گونه قارچ فیتوفتورا (Phytophthora cactorum،P. nicotinae ، P.citricola و P.citrophthora) توسط آزمون های گلخانه ای و صحرایی انجام گردید. در این پژوهش، آزمایش گلخانه ای برای ارزیابی ژنوتیپ ها، در قالب طرح آزمایشی کاملا تصادفی با 5 تکرار انجام و آزمایش باغی نیز برای ارزیابی ژنوتیپ ها بر اساس تلقیح گونه های مختلف فیتوفتورا به تفکیک در زیر پوست طوقه نهال های کاشته شده در قالب طرح بلوک های کامل تصادفی با 5 تکرار انجام گردید. نتایج ارزیابی صفات مورد بررسی ژنوتیپ ها در گلخانه نشان داد که ژنوتیپ های 100 ، 155، 162، 171، 188،194، 199، 200، 224 و 266 کمترین حساسیت را نسبت به گونه های P. nicotianae ،P.citricola، P.cactorum و P.citrophthora دارند. همچنین نتایج آزمون ارزیابی ژنوتیپ ها در باغ، کمترین سطح نکروز بافتی در روی طوقه نهال ها به گونه های فیتوفتورای مورد برررسی را در بین ژنوتیپ های 106، 139، 162، 188، 195، 224، 266 و 270 نشان داد. نتایج کلی این تحقیق نشان داد بیماریزاترین گونه های فیتوفتورا روی ژنوتیپ های محلب P.citricola و P.cactorum بودند و سه ژنوتیپ 266، 224 و 188 بیشترین پتانسیل مقاومت به گونه های P. nicotianae، P.citricola، P.cactorum و P.citrophthora را داشتند.
    کلیدواژگان: پایه، پوسیدگی طوقه و ریشه، گیلاس
  • الهام الهی فرد، نرگس شمشیرگرزاده، علیرضا ابدالی مشهدی، محمدرضا مرادی تلاوت صفحات 456-465
    مقاومت عرضی منفی بر اثر بروز مقاومت به تریازین ها در چندین مورد از بایوتایپ های مقاوم گزارش شده است؛ به طوری که این پدیده منجر به بروز حساسیت زیاد در این بایوتایپ ها نسبت به علف کش های فنیل اوره و سایر بازدارنده های فتوسنتز در فتوسیستم 2 می شود. بدین منظور، مقاومت عرضی منفی در توده های مقاوم به علف کش های خانواده تریازین علف هرز درنه در مزارع نیشکر کشت و صنعت کارون شوشتر پژوهشی در طی سال های 94-1393 با استفاده از آزمایش های گلدانی در دانشگاه کشاورزی و منابع طبیعی رامین خوزستان مورد بررسی قرار گرفت. نتایج آزمایش غربال اولیه براساس شاخص های اندازه گیری شده نشان داد سه توده به علف کش آترازین مقاوم بودند. همچنین، نتایج بدست آمده از آزمایش دز- پاسخ بر مبنای شاخص مقاومت توده ها نشان داد که توده های R1، R2 و R3 به ترتیب با درجاتی بین تا 26/12، 59/6 و 75/3 بر مبنای وزن تر و 37/5، 22/4 و 71/4 تعداد گیاهان زنده مانده به علف کش آترازین مقاوم بودند. نتایج حاصل از این پژوهش مقاومت عرضی منفی توده های درنه مقاوم به علف کش آترازین را نسبت به علف کش های تبوتیورون، لینورون، دایورون و دایورون+ هگزازینون را در محدوده بین 56/0 تا 62/1بر مبنای وزن تر و بین 52/0 تا 26/3 بر مبنای تعداد گیاهان زنده مانده نشان داد. همچنین، توده های مقاوم بیشترین مقاومت عرضی منفی (حساسیت) را نسبت به علف کش دایورون + هگزازینون نشان دادند.
    کلیدواژگان: دز- پاسخ، علف کش های فنیل اوره، علف کش های مخلوط
  • نامدار مرادی، حشمت الله رحیمیان، علی دهستانی، ولی الله بابایی زاد، یاسر یعقوبیان صفحات 466-474
    خیار یکی از اقتصادی ترین صیفی جات تولیدی در ایران است که به شدت توسط سفیدک پودری مورد هجوم قرار می گیرد. یکی از موثرترین راه های کنترل اپیدمی این بیماری شناسایی و کاربرد ژنوتیپ های مقاوم به بیماری است. در مطالعه حاضر تعداد 23 رقم خیار گلخانه ای و مزرعه ای از نظر مقاومت به سفیدک پودری غربالگری شده و ارقام مقاوم بر اساس برآورد درصد شاخص بیماری (PDI) شناسایی شدند. در ادامه فلورسانس کلروفیل برگ در 5 رقم از گروه های مقاوم، نیمه مقاوم و حساس برآورد و مورد تجزیه و تحلیل قرار گرفت. بر اساس نتایج برآورد شاخص بیماری، اختلاف قابل ملاحظه ای از نظر مقاومت به این بیماری در بین ارقام مشاهده شد به طوری که در چهار گروه مقاوم، نیمه مقاوم، نیمه حساس و حساس دسته بندی شدند. دو رقم گلخانه ای CLE و Green Magic به ترتیب با شاخص بیماری 78/7 و 33/8 مقاوم ترین و دو رقم مزرعه ای Beit Alpha و SuperN3 به ترتیب با شاخص بیماری 11/31 و 67/31 حساس ترین ارقام شناخته شدند. در تجزیه واریانس شاخص های فلورسانس کلروفیل، اثر بیماری بر 3 شاخص فلورسانس حداقل (Fo)، فلورسانس متغیر (Fv) و شاخص سرزندگی گیاه (Fv/Fm) و اثر رقم بر شاخص Fo معنی دار بود (P
    کلیدواژگان: شاخص سرزندگی، درصد شاخص بیماری، فتوسنتز، فتوسیستم II
  • ندا هلالات، مهدی نصراصفهانی، مجید اولیا صفحات 475-487
    جهت بررسی کنترل غیر شیمیایی نماتد سیستی چغندر قند،آزمایشی با استفاده از کودهای آلی در دو سطح مزرعه و گلخانه صورت پذیرفت. در این آزمایش، از کودهای نپوسیده دامی، در مقادیر 20، 40 و 60 تن در هکتار; مرغی 10، 20 و 40 تن در هکتار; کود سبز (ضایعات برگ کلم); دو نوع کمپوست 08 (8/0 میلی متر) و 015 (15/0 میلی متر)، و ورمی کمپوست، هر کدام به میزان20، 40 و 60 تن در هکتار انجام گردید. جمعیت نهایی، تعداد تخم و لارو سن دوم موجود، در هر گرم خاک، مبنای تجزیه وتحلیل آماری قرار گرفت. هم‏چنین، فاکتور تولید مثل و درصد کاهش و یا افزایش جمعیت نماتد سیستی چغندرقند محاسبه گردید. نتایج حاصله نشان داد، تیمار کود مرغی با 32/93 در صد، بیشترین اثر را در کاهش جمعیت نماتدسیستی چغندر قند و کمترین مقدار، در کود حیوانی 20 تن در هکتار با 77/44 در صد کاهش داشته است. کمترین میزان فاکتور تولید مثل، در تیمار کود مرغی بود. تیمارهای کود کمپوست 015، کمپوست 08، ورمی کمپوست، برگ کلم و کود گاوی در رده های بعد قرار گرفتند. نتایج، در خصوص میزان محصول، عیار قند و سایر شاخص ها در تیمارهای مختلف چغندر قند مورد بررسی، نشان داد که تفاوت قابل‏توجه در بین تیمارها وجود دارد. به طوری‏که کود مرغی 20 و 40 تن در هکتار، به ترتیب با 55/27 و 93/26 تن محصول در هکتار، بیشترین مقدار وکمترین آن، در تیمارهای شاهد و برگ کلم 20 تن در هکتار، به ترتیب با 77/13 و 20/14 تن در هکتار بود.
    کلیدواژگان: نماتد سیستی، چغندرقند، کودهای آلی، Heterodera schachtii
  • سید علیرضا اسمعیل زاده حسینی، محمود دهقانی اشکذری، مصطفی عابدی تیزکی صفحات 488-495
    روناس (Rubia tinctorum) یکی از محصولات مهم زراعی با مصارف دارویی و صنعتی در استان یزد می باشد. به منظور شناسایی قارچ های همراه با بذور روناس و تولید کننده توکسین، طی سال های زراعی 91 لغایت 93 از بذور روناس در مناطق مهم کاشت آن در استان یزد شامل اردکان و بافق نمونه برداری به عمل آمد. پس از کشت و خالص سازی جدایه های قارچی در محیط های کشت های سیب زمینی دکستروز آگار (PDA) و برگ میخک آگار (CLA)، شناسایی تکمیلی با آغازگرهای اختصاصی هر گونه با استفاده از واکنش زنجیره ای پلیمراز صورت گرفت. ردیابی قارچ های دارای پتانسیل تولید مایکوتوکسین 8-کتوتریکوتسین از جمله دی اکسی نیوالنول (DON) از طریق آغازگرهای اختصاصی ژن Tri13 انجام شد. جهت تایید پتانسیل تولید مایکوتوکسین DON در جدایه های فوزاریوم از کروماتوگرافی مایع با کارایی بالا (HPLC) استفاده شد. در مجموع 249 جدایه قارچی از بذور روناس جداسازی شد که متعلق به شش جنس قارچی شامل فوزاریوم، آسپرژیلوس، پنیسلیوم، آلترناریا، رایزوکتونیا و رایزوپوس بودند که بیشترین فراوانی قارچ های جداسازی شده مربوط به فوزاریوم با 71 درصد کل جدایه ها بود. در بین قارچ های فوزاریوم، گونه های F.solani (55 جدایه) و F.oxysporum (41 جدایه) بیشترین فراوانی را داشتند. گونه های F. poae، F. semitectum و F. equiseti توانایی تولید دی اکسی نیوالنول را دارا بودند. ژن Tri13موثر در تولید دی اکسی نیوالنول نیز در این سه گونه ردیابی گردید و در آزمایش HPLCهمه قارچ های فوزاریوم مورد بررسی پتانسیل تولید مایکوتوکسین مورد نظر را داشتند.
    کلیدواژگان: Rubia tinctorum، مایکوتوکسین، یزد
  • مریم پهلوان یلی، محسن محمدی انایی صفحات 496-504
    شته مومی کلم (Brevicoryne brassicae) و شته سبز گندم (Schizaphis graminum) به ترتیب از آفات مهم کلزا و گندم می باشند که بصورت قابل توجهی زراعت این محصولات را از طریق تغذیه بصورت مستقیم و انتقال عوامل بیماریزای ویروسی بصورت غیر مستقیم کاهش می دهند. پیدایش مقاومت به سموم شیمیایی و اثرات حاد و مزمن ناشی از کاربرد آن ها باعث استفاده از ترکیبات ثانویه گیاهی بصورت عصاره و اسانس به منظور کنترل آفات شده است. از جمله این ترکیب ها می توان به عصاره میوه زیتون تلخ و پوست لیموترش اشاره کرد. در این تحقیق اثر دو عصاره اتانولی مذکور در سه غلظت متفاوت (10، 50 و 80 میکروگرم بر میلی لیتر) روی درصد تلفات شته مومی کلم و شته سبز گندم مورد بررسی قرار گرفت. نتایج نشان داد کاربرد عصاره اتانولی میوه زیتون تلخ در غلظت 80 میکروگرم بر میلی لیتر پس از 36 ساعت باعث 100 درصد مرگ و میر روی شته ها می شود که در مقایسه با عصاره پوست لیموترش به طور معنی داری بیشتر بود. همچنین در این مطالعه، مقدار فنل کل در عصاره میوه زیتون تلخ (74/2 میلی گرم بر گرم وزن تر) نسبت به عصاره پوست لیموترش (79/1 میلی گرم بر گرم وزن تر) بیشتر بوده است که می تواند با اثر کشندگی بالاتر زیتون تلخ روی این شته ها در ارتباط باشد. نتایج این تحقیق می تواند در کنترل شته های مذکور برای تولید محصولات سالم و ارگانیک مفید باشد.
    کلیدواژگان: ترکیبات ثانویه گیاهی، غلظت، فنل
  • محمد ولی تقدسی، محمد رحیم معینی، غلامعلی اکبرزاده شوکت، هاشم کمالی، رئوف کلیایی صفحات 505-510
    کرم سیب Cydia pomonella L.آفت کلیدی سیب در ایران است. به علت ناکارآمدی سایر روش های کنترلی، استفاده از حشره کش ها، اولین گزینه، عمومی ترین و موفق ترین روش کنترل این آفت است. در تحقیق حاضر تاثیر حشره کش دیفلوبنزورون (دیمیلین(SC48% ® به همراه حشره کش های فوزالون )زولون(SE 35% ® و تیاکلوپرید (کالیپسو® 48% SC) و شاهد در 4 تکرار و در سه منطقه ارومیه، زنجان و بجنورد به مدت یک سال، در قالب طرح بلوک های کامل تصادفی مورد بررسی قرار گرفت. نتایج به دست آمده نشان داد که تیمار دیمیلین با میانگین درصد آلودگی 23/0± 02/4 درصد، 4/1±26/7 و 42/0±06/2 درصد به ترتیب در ارومیه، زنجان و بجنورد دارای کمترین و تیمار شاهد با میانگین 94/4±37/57، 03/3±21/45 و 08/3±12/57 درصد دارای بالاترین میانگین درصد آلودگی بود. تیمار کالیپسو با میانگین درصد آلودگی 43/0±02/1 و 44/0 ±00/3 به ترتیب در ارومیه و زنجان و تیمار زولون با میانگین درصد آلودگی 29/0± 65/3 در ارومیه در رده مشابه آماری با دیمیلین قرار گرفتند. جمع بندی نتایج نشان می دهد که ترکیب دیمیلین را می توان، در صورت ضرورت جانشین ترکیبات رایج نمود.
    کلیدواژگان: تیاکلوپرید، فوزالون، کنترل شیمیائی
  • مرجان سیدی، مهدی ترک صفحات 511-517
    کنه شکارگر Amblyseius swirskii و قارچ بیمارگرBeauveria bassiana از دشمنان طبیعی مهم سفید بالک گلخانه Trialeurodes vaporariorum هستند. در بررسی کارایی و انتخاب دشمنان طبیعی، تعیین ترجیح غذایی آنها، هنگامی که دشمن طبیعی در برابر میزبان آلوده یا غیر آلوده به عوامل بیمارگر قرار می گیرد، از اهمیت خاصی برخوردار است. در این تحقیق ترجیح غذایی کنه شکارگر دو روز پس از بالغ شدن در برخورد با پوره سن سوم سفید بالک گلخانه غیر آلوده و تیمار شده با قارچ B. bassiana در دو تیمار زمانی 24 و 48 ساعت بعد از آلودگی شکار با استفاده از شاخص بتای منلی تعیین شد. شکارگرهایی که 24 ساعت گرسنگی داده شده بودند بر روی دیسک های برگی خیار رهاسازی شدند و پس از 24 ساعت تعداد سفید بالک های مصرف شده شمارش شدند. آزمایش درون ظروف پتری تهویه دار و به مدت 24 ساعت انجام شد. براساس نتایج مقدار شاخص در بازه زمانی 24 و بازه زمانی 48 ساعت پس از تیمار شدن میزبان به قارچ، به ترتیب 19/0±15/4 و 12/0±23/2 برآورد شد. نتایج نشان داد، A. swirskii در تغذیه از سفید بالک های غیر آلوده در مقابل سفید بالک های تیمار شده با قارچ در بازه زمانی 24 ساعت (0034/0>P) و 48 ساعت (0001/0P
    کلیدواژگان: دشمنان طبیعی، شاخص بتای منلی، قارچ بیمارگر حشرات، کنترل بیولوژیک
  • سمیرا سارانی، سید غلامرضا موسوی صفحات 518-526
    به منظور بررسی تاثیر تراکم بوته و تداخل علف هرز بر عملکرد و اجزای عملکرد سورگوم دانه ای رقم سراوان آزمایشی به صورت فاکتوریل در قالب طرح بلوک های کامل تصادفی در مزرعه تحقیقاتی دانشگاه آزاد اسلامی بیرجند در سال 1392 با سه تکرار اجرا گردید. تیمارهای آزمایشی شامل سه سطح تراکم بوته (10، 20 و 30 بوته در متر مربع) و چهار سطح تداخل علف هرز (تیمار شاهد عاری از علف هرز، تداخل تامرحله 6-8 برگی، تداخل تا مرحله ظهور پانیکول و تداخل تمام فصل) در نظر گرفته شد. با افزایش تراکم از 10 به 30 بوته در متر مربع، طول پانیکول، تعداد پانیکول در بوته، تعداد دانه در پانیکول، وزن هزار دانه، تعداد علف هرز و وزن خشک علف هرز در متر مربع به طور معنی دار و به ترتیب 1/7، 5/45، 5/12، 2/16، 3/12، 6/27 و 8/16 درصد کاهش یافت اما تعداد پانیکول در متر مربع و عملکرد بیولوژیک 3/54 و 7/56 درصد افزایش یافت. تیمار عاری از علف هرز نسبت به تیمار تداخل تا انتهای دوره رشد از برتری معنی دار 3/14، 3/20، 4/30، 7/270، 122 و 3/149 درصدی به ترتیب در طول پانیکول، تعداد پانیکول در متر مربع، تعداد دانه در پانیکول، وزن هزار دانه، عملکرد دانه و عملکرد بیولوژیک برخوردار بود. به طور کلی بر اساس نتایج این تحقیق با توجه به این موضوع که رقم سراوان یک رقم دو منظوره (دانه ای- علوفه ای) است، پیشنهاد می گردد تیمار تراکم 30 بوته در متر مربع و عاری نگهداشتن مزرعه از علف های هرز برای زراعت این گیاه مورد توجه قرار گیرد.
    کلیدواژگان: بیوماس علف هرز، پانیکول، تعداد بوته، رقابت، وزن هزار دانه
  • هدی صالحی پور، حسنعلی واحدی، ناصر معینی نقده، عباسعلی زمانی صفحات 527-539
    کرم میوه ی گوجه فرنگی Helicoverpa armigera و کرم برگ خوار چغندرقند Spodoptera exigua از آفات مهم گوجه فرنگی هستند. تراکم جمعیت این آفات و میزان پارازیتیسم آن ها توسط زنبور پارازیتوئید Habrobracon hebetor رهاسازی شده، روی ارقام گوجه فرنگی، در شرایط مزرعه، طی سال زراعی 93-1392 بررسی شد. شروع نمونه برداری از هفته ی پنجم پس از کشت نشا آغاز و تراکم جمعیت آفات مورد بررسی و میزان پارازیتیسم لارو آن ها محاسبه شد. ارقام مورد آزمایش شامل، اطمینان، ارس، AB2، Rio fojiu، Mariana، Gempride، King ston، Super queen، 9704، 9706، 9553 و 6515 PS بودند. نتایج این مطالعه نشان داد، با وجود اختلاف معنی دار تراکم جمعیت این دو آفت، در تاریخ های مختلف نمونه برداری، میانگین تراکم آفات در ارقام مختلف، معنی دار نبود. بیش ترین تراکم لارو کرم میوه ی گوجه فرنگی در اواخر تیرماه، مصادف با هفته ی نهم و دهم کشت گوجه فرنگی و بیش ترین میزان پارازیتیسم لارو آن در اواخر تیر و اوایل مرداد ماه در مزرعه مشاهده شد. بالاترین تراکم جمعیت کرم برگ خوار چغندرقند در دهه ی اول تیرماه هم زمان با هفته ی ششم و هفتم رشد گوجه فرنگی و بیش ترین میزان پارازیتیسم لاروهای آن در اواخر تیرماه در هفته ی سوم پس از رهاسازی اتفاق افتاد. نتایج کلی این مطالعه نشان داد، استفاده از زنبور پارازیتوئید H. hebetor به منظور کنترل لارو آفات مورد بررسی در برنامه مدیریت تلفیقی حایز اهمیت می باشد. ارقام AB2 و Kingstone به ترتیب بیش ترین میانگین تراکم لارو کرم میوه ی گوجه فرنگی و کرم برگ خوار چغندرقند را داشته و کم ترین میانگین تراکم لارو آفات به ترتیب روی رقم Kingstone و 6515 مشاهده شد.
    کلیدواژگان: پارازیتوئید Habrobracon hebetor، کرم برگ خوار چغندرقند، کرم میوه ی گوجه فرنگی، کرمانشاه
  • اصغر سمیعی، محسن مهرور، محمد زکی عقل صفحات 540-547
    ویروس لکه سیاه برگ چغندر قند (BBSV) یکی از ویروس های خاکزاد جدید گزارش شده از مزارع چغندرقند در دنیا است که به لحاظ داشتن علائم مشابه (ریشه ریشی) با ویروس رایزومانیا Beet necrotic yellow veinvirus و احتمالا برخی برهمکنش های متقابل با این ویروس اهمیت اقتصادی بالایی دارد. به منظور بررسی پراکنش BBSV در مزارع چغندرقند ایران در سال های زراعی 1393-1390 در مجموع 309 مورد نمونه ریشه چغندرقند جمع آوری گردید. بررسی نمونه ها با استفاده از آزمون RT-PCR نشان داد که 147 مورد از 309 کل نمونه ها (48 درصد) به این ویروس آلوده بودند. همچنین این ویروس دارای یک قطعه ماهوارهای است که در 30 مورد (10 درصد) از نمونه ها ردیابی گردید. بر این اساس وجود ویروس BBSV در مزارع چغندر قند استان های خراسان رضوی، شمالی، جنوبی، لرستان، اردبیل، آذربایجان شرقی، آذربایجان غربی، قزوین، همدان، کرمان، کرمانشاه و زنجان تائید گردید. براساس اهمیت پراکنش جغرافیائی مناطق چغندرکاری و علائم ایجاد شده در گلخانه، 5 جدایه شامل آذربایجان غربی، همدان، خراسان رضوی (مشهد)، خراسان شمالی (شیروان) و کرمانشاه برای بررسی تنوع ژنتیکی انتخاب گردیدند. دو ناحیه مهم شامل پروتئین پوششی و 3''UTR این پنج جدایه با یک جدایه چینی و یک جدایه آمریکائی مورد مقایسه قرار گرفت. در مجموع تحلیل توالی این دو ناحیه نشان داد که جدایه چینی و آمریکائی به یکدیگر شباهت بیشتری دارند تا با جدایه های ایرانی. شباهت جدایه های ایرانی با جدایه های چینی و آمریکائی در هر دو ناحیه حدود 88 درصد بود. در بین جدایه های ایرانی میزان شباهت بالا و بین 98 تا 99 درصد بود و تنها جدایه خراسان شمالی (شیروان) با شباهت کمتر در دسته ای جدا قرار گرفت. به نظر می رسد تفاوت ها در ناحیه 3''UTR خیلی موثر نبوده و در تمام جدایه ها ژنوم ویروس به خوبی بیان و تکثیر می گردد. اما در ناحیه پروتئین پوششی تغییرات آمینو اسیدها بخصوص در ناحیه N-terminal در ایجاد علائم و بر همکنش با سایر ویروس های خاکزاد تاثیر بسزائی داشته است.
    کلیدواژگان: ایران، BBSV، PCR، Beta vulgaris
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  • Mehdi Mehrabi-Koushki, Maryam Bavarsad, Reza Farrokhi-Nejad Pages 362-373
    Introduction
    Trichoderma is monophyletic (16), with teleomorphs in the genus Hypocrea. Some cryptic Trichoderma species are hidden within morphological species complexes and can only be elucidated by in-depth molecular studies. The genealogical concordance phylogenetic species recognition (GCPSR) using several non-linked genes are needed to give accurate identification of Trichoderma spp. (6). Although the ITS region has been successfully used for species delimitation of Trichoderma and Hypocrea (5), but, it is not sufficient for accurate identification of some species. Translation elongation factor 1α gene (tef1α) is a reliable barcode for Fusarium (9), Trichoderma and Hypocrea (5). Here, ITS and tef1α genes were selected as candidate DNA barcodes to identify Trichoderma isolates.
    Material and
    Methods
    40 Trichoderma isolates used in this study were from a fungal collection archived in the plant pathology laboratory in the Department of Plant Protection at the Shahid Chamran University of Ahvaz. Spore suspension (105/ml) prepared from single spore cultures of each Trichoderma isolates was added into flasks containing PDB medium. The mycelia were harvested from the growth medium by washing biomass with sterilized distilled water on filter papers. Mycelial biomasses were freeze-dried and then powdered into mortar containing liquid nitrogen by pestle. The genomic DNA was isolated according to modified method established by Reader and Broda (1985). The universal primers (ITS1–F; 5'-TCCGTAGGTGAACCTGCGG-3' and ITS4-R; 5'-TCCTCCGCTTATTGATATGC-3') were employed for amplifying around 700bp from 18s, ITS1, 5.8s, ITS2 and 28s rDNA regions. The specific primers (tef1α71-f; 5'-CAAAATGGGTAAGGAGGASAAGAC-3' and tef1997-R; 5'-CAGTACCGGCRGCRATRATSAG-3') were employed for amplifying around 950bp from exon1 to exon6 regions of tef1α gene containing introns 1 to 5 (Shoukouhi and Bisset, 2008). PCR products were purified through ethanol-precipitation method and then sequenced using forward and reverse primers by Macrogen Company. The Sequences were edited and assembled using BioEdit v. 7.0.9.0 (Hall 1999) and DNA Baser Sequence Assembeler v4 programs (2013, Heracle BioSoft, www.DnaBaser.com), respectively. These sequences were submit-queried against the NCBI non-redundant database and related to known DNA sequences by BLASTn algorithm to assign putative identity. They also were subjected to the TrichO Key (Druzhinina et al. 2005) and TrichoBLAST (Kopchinskiy et al. 2005) for more detection.
    Result and
    Discussion
    Approximately 550 and 850 bases of the ITS and tef1α regions were sequenced from the isolates studied and then deposited in the GenBank. There was no ITS sequence of T. capillare in databases and we here indexed it and more sequence from its tef1α gene in GenBank. The annotation of indexed sequences showed which multiple insertion-type frame shifts have interestingly occurred into reading frame of tef1α gene belong to T. capillare Isf-7 isolate (Fig. 1). To identify isolates of Trichoderma, ITS and tef1α sequences were subjected to the TrichO Key (Druzhinina et al. 2005), TrichoBLAST ( Kopchinskiy et al. 2005) and BLASTn Search. The analysis and comparison of ITS and tef1α data with reference sequences in ISTHT and GenBank showed which the isolates place in seven species as follow: T. harzianum Rifai, T. virens (J.H. Mill., Giddens & A.A. Foster) Arx, T. pleuroticola Yu & Park, T. asperellum Samuels, Lieckf & Nirenberg, T. koningiopsis Oudem., T. brevicompactum Kraus, Kubicek & Gams and T. capillare Samuels & Kubicek. In BLASTn search, ITS and tef1α regions separately provided unambiguous identification for isolates of T. virens, T. koningiopsis and T. brevicompactum while ITS region provided ambiguous identification for Isolates of Trichoderma harzianum, T. capillare Samuels & Kubicek, T. pleuroticola and T. asperellum. Here, tef1α region could provide more accurate identification as good DNA barcoding (Table 2). The isolates showed the sequence identity ranging from 96 to 100% for tef1α locus and 88 to 99% for ITS locus. Different identities related to ITS and tef1α genes indicated that single gene identification is not accurate, particularly for Trichoderma species, if the identification is based on ITS regions (Druzhinina and Kubicek, 2005). Among the species identified, T. capillare is the first report for Iran mycoflora. This species was firstly described by Samuels et al. (2012) and phylogenetically associated with other species of Longibrachiatum Clade.
    Conclusions
    Here, of seven species of Trichoderma identified, the species of T. capillare is newly reported in Iran. Our studies demonstrate ultimately that, despite ITS region, tef1α gene is quite reliable in identification and phylogeny of Trichoderma species.
    Keywords: DNA-barcoding, morphology, phylogenetic clustering
  • Aliasghar Chitband, Reza Ghorbani, Mohammad Hassan Rashed Mohassel, Mahbubeh Nabizade Pages 374-387
    Introduction
    The assessment of the effect of mixtures could be based on various concepts whether we work within toxicology, pharmacology or weed control. Combinations of certain herbicides can give better weed control than use of the individual herbicide alone and/or loss of weed control when use of certain other herbicides in combination. Predicting the joint action of mixtures is extremely difficult, unless the compounds are known to interact at the same site of action. These most common methods to analyze the joint action of herbicide mixtures are the Additive Dose Model (ADM) or the Multiplicative Survival Model (MSM). The ADM assumes the two compounds have similar modes of action (do not interact) in the receiver plant, i.e. effective doses of each component will not change by mixing. ADM has been widely accepted as a valid method to estimate joint action of mixtures sharing the same or similar action mechanisms in the receiver plant. MSM has been reported to yield more accurate results for mixture toxicity than ADM do when the components exhibited different or dissimilar modes of action in the receiver plant. ADM or Concentration Addition (CA) is used here to test for deviation of additivity of doses using the ADM isoboles as reference; any deviation from the ADM is characterized by antagonism when the efficacy of a mixture is lower than predicted by the reference model and synergistic when the efficacy is higher than predicted.
    Materials And Methods
    In order to determine joint action of some usable important broadleaf herbicides in sugar beet, six experiments were conducted at the research glasshouse in Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. The plants were sprayed with seven doses of commercial formulation of desmedipham phenmedipham ethofumesate (Betanal Progress- OF®, 427 g a.i. L-1, Tragusa, Spain), chloridazon (Pyramin®, 1361 g a.i. L-1, BASF, Germany), clopyralid (Lontrel®, 149 g a.i. L-1, Golsam, Gorgan, Iran) either alone or in binary fixed-ratio mixtures of the three herbicides. The ratio of the herbicides of the binary mixtures were chosen with the aim of obtaining a contribution to the overall effect of the two herbicides of 100:0, 75:25, 50:50, 25:75, and 0:100 for seven-mixture-ratio experiments. Spraying was performed by overhead trolley sprayer (Matabi 121030 Super Agro 20 litre sprayer), 8002 flat-fan nozzle at 300 kPa and a spray volume of 200 Lha-1. The plants were treated at 21 days (at the four- to six-true leaf stage) after planting. Dose-response curves were estimated by fitting a three log-logistic dose–response model against dose for ED50 and ED90 response levels. ADM was used as reference model of joint action with their equations. As the results with the herbicide mixtures originate from up to twelve separate experiments it was necessary to standardize the x- and y-axes so that the ED50, ED80 and ED90 doses of the herbicides applied separately were always fixed to 1.
    Results
    Discussion
    The results showed that mixtures of chloridazon and clopyralid were less phytotoxic than predicted by ADM particularly in Amaranthus retroflexus at ED50 and ED80 response levels. These binary mixtures of herbicides were either followed ADM or less than predicted by ADM in Solanum nigrum. In contrast, mixture of desmedipham phenmedipham ethofumesate and clopyralid was synergistic in both species. Whereas desmedipham phenmedipham ethofumesate and chloridazon binary mixture was synergistic in Solanum nigrum to followed according to ADM in Amaranthus retroflexus.
    Conclusion
    The present study has revealed that mixtures of photosystem II, lipid biosynthesis and auxin inhibitor herbicides either followed ADM, or performed better than predicted by ADM, i.e. applying mixtures of these herbicides will not result in an excessive use of herbicide compared to applying the herbicides separately. In contrast, mixtures of chloridazon and clopyralid were trend antagonistic and the two herbicides should not be applied in mixture.
    Keywords: additive dose model_antagonism_binary mixture_desmedipham + phenmedipham + ethofumesate_synergism
  • Abbas Abbasian Pages 388-395
    In order to evaluate the effect of freezing stresses on invasive plant of Centaurea balsamita, an experiment was performed as factorial, based on completely randomized design with five replications at Ferdowsi University of Mashhad, Faculty of Agriculture during 2014. In this experiment Centaurea balsamita after their period of cold acclimation in the falling exposed to seven freezing temperatures (0, -3, -6, -9, -12, -15 and -18 °C). Potted plants were grown in natural conditions and maintained for acclimation, until 2-4 and 4-8 leaf stages and then, the plants were placed in a thermogradian freezer in different chilling and the freezing temperature (FT) regimes. The cytoplasm membrane stability of Centaurea balsamita was evaluated using electrolyte leakage; then the lethal temperature of 50% of samples was determined based on leakage percentage (LT50el). Survival percentage was evaluated by counting the number of live plants in each pot. Then, at the end of the recovery period, the lethal temperature for 50% of survival percentage (LT50su) and reduction temperature for 50% of dry weight (RDMT50) were determined (three weeks after the application of freezing treatment). According to the results of the first experiment, temperature reduction from -12 °C to -15 °C leads to significant increase (P≤ 0.05) in electrolyte leakage of Centaurea balsamita. In addition, temperature reduction from -9 °C to -12 °C results in significant decrease (P≤ 0.05) in survival percentage and biomass of Centaurea balsamita. The results showed that LT50el, LT50su and RDMT50 of cold acclimated Centaurea balsamita in fall conditions were -13.2 °C, -126 °C and -11.8 °C, respectively.
    Keywords: LT50, RDMT50, electrolyte leakage, Cold acclimation, Survival percentage
  • Habibeh Soltani, Ali Ghanbari, Mehdi Rastgoo, Ghorban Ali Asadi Pages 396-408
    Introduction soybean (Glycine max L.) plays an important role in three major markets of grains, oil and meal. damage of weeds in soybean generally 13 to 60 and sometimes more than %80 have been reported Farming methods through proper management, sowing date and by use of optimum density could be a strategy for the development of ecological competitiveness of crops and inhibit weed growth are the comparison the growth indices to design interference models of weed and crop and estimate crop yield loss in competition with weed is essential and allow to plant breeding researcher to choice the more competitive varieties of crop in competition with weed.
    Materials and Methods With the aim of influencing sowing date and plant density on the growth indices and evaluation the competitive ability of soybean cultivar Williams with weeds, an experiment was conducted in 2013, at Agricultural Research Station, Ferdowsi University of Mashhad, as split-split based on a randomized complete block design with three replications. Main plot included three sowing dates levels (17 April, 12 May, 6 June) and sub - plots included four crop density (30, 40, 50 and 60 plant . m-2) and sub - sub plots included weed management of two level (weed infested and weedy control). First sampling was started at 35 days after planting and was every 14 days until the end of growth period. Leaf area index, dry matter, crop growth rate and the growth rate were calculated
    Results and Discussion The results showed that 11 species weed belonging to 9 families observed and identified. In the early stages of growth, leaf area index and dry matter increased slowly, but in the seven to eight leaf stage of plant growth (Log phase), leaf area index and dry matter increased rapidly, and a little upon entry to the plant Physiological maturity period (Early seedling) peeks, and again began to decline at the end of seedling. The sowing date 12 May in contrast to early sowing date (17 April) and delayed planting date (6 June) produced greater leaf area index, dry matter and growth rate. Low temperature in the early stage of growth early planting and the reduced length of the growing season due to the high temperature in delayed planting results in reduced leaf area index and dry matter. The more density, the later sowing date results in the more dry matter and leaf area index. Maybe, sowing date together with more density was compensated yield loss. The presence of weeds in soybean density from 30 to 60 plants per square meter, the leaf area index and dry matter increased. Most of crop growth rate (22.24) was observed in sowing date, 12 May and with 50 plants per square meter and without weed. The maximum growth rate (0.127) was observed on sowing date 6 June and 40 plants per square meter and in condition of weed control. difference between the dry matter, leaf area index, crop growth rate and the growth rate in condition of weed interference (all season) were significant Results indicated that the maximum economic yield is related to sowing date, 12 May and 40 plants per square meter. Also, in this situation improved growth indices and increased competitive ability against weed were observed.
    Conclusions The results of this study showed that dry matter, leaf area meter, crop growth rate and the growth rate in the presence of weed were declined. Early and late planting reduced dry matter, leaf area index and the rate of growth of soybeans. It̓̓s concluded that such t the low temperature in early growth period in early planting and reduced length of growing season delayed planting due to the high temperature reduced dry matter, leaf area index. The low density (density 30 and 60 plants per square meter) impacted growth indicators. There for, the density should be selected based on plant, ecological needs during environmental conditions and the growing season. In conclusion the sowing date 12 May and density 40 plants per square meter are the best condition that improve growth indices and increase the competitiveness of soybean against the weed, and these are as ecological solution for reduced pesticide usage and reduced the effects of environmental pollution and men's health.
    Keywords: crop growth rate, growth rate, interference, leaf area meter, yeild seed
  • Majid Abbaspoor Pages 409-419
    Introduction Saffron is derived from the stigmas of the saffron (Crocus sativus L). It is the world’s most expensive spice and has been widely used in many countries. It is also increasingly used for medicinal purposes. Weed control in this perennial, small and low growing crop, needs a lot of labor work. Chemical approach is one of the most effective methods for weed control in saffron. Currently, some herbicide options are available for applications in saffron. For example, satisfactory broadleaved weed control would be achieved by post-emergence application of metribuzin and ioxynil after harvesting saffron flowers. Application of glyphosate and/or 2, 4-D / 2, 4-DB are used to clean up the beds prior to the new season’s flowering and growth of saffron in New Zealand. The selective weed control of weeds in saffron has not been widely reported elsewhere but some in Iran. The choice of herbicide(s) depends on the kind of weeds present. In some literatures metribuzin showed promising results for weed control in saffron fields. It is selectively used for control of annual grasses and numerous broad-leaved weeds. The objective of this study was the evaluation of the efficacy of 15 herbicides with different mode of actions, selected on the basis of dominant weed flora and previous studies, on weeds grown in saffron fields.
    Materials and Methods A field study was conducted to evaluate the efficacy of herbicides for weed control in saffron (Crocus sativus) in Agricultural and Natural Resources Research and Education Center of Khorasan Razavi Province, Mashhad, in 2014-2015 growing season. The experiment was conducted in a completely randomized block design with three replications. Treatments were consisted of metsulfuron-methyl sulfosulfuron (Total®) at dose of 40 g ha-1, sulfosulfuron (Apirus®) at dose of 26.6 g ha-1, oxadiazon (Ronestar®) at dose of 2 l ha-1, oxyflurofen (Goal®) at dose of 2 l ha-1, mesosulfuron idosulfuron diflufenican (Othello®) at dose of l.6 l ha-1, metribuzin (Sencore®) at dose of 750 g ha-1 (applied after saffron harvest in autumn as pre emergence of weeds), triasulfuron dicamba (Lintur®) at dose of 165 g ha-1, atrazine (Gesaprim®) at dose of 1000 g ha-1, Bensulfuron methyl (Londax®) at dose of 50 g ha-1, bromoxinyl MCPA (Bromicide®) at dose of l.5 l ha-1, 2, 4-D MCPA (U-46 combi fluid ®) at dose of l.5 l ha-1, nicosulfuron (Cruz®) at dose of l.5 l ha-1, haloxyfop methyl (Gallant super®) at dose of l l ha-1, bentazon (Basagran®) at dose of 3 l ha-1, tribenuron methyl (Granstar®) at dose of 20 g ha-1 plus weed free and weedy checks. Herbicides were sprayed at early stage of weed growth (2-3 leafy stage) (except for metribuzin which sprayed soon after flower harvest in autumn and pre emergence of weeds) with Matabi® rechargeable sprayer calibrated to deliver 330 l ha-1. Four weeks after spraying, density and dry matter of dominant weed species were measured. At harvest, flower number, flower fresh weight and dry matter of 50 stigmas were measured. Data were analysed by SAS (9.2) software and mean were grouped by Duncan multiple range test (alpha=0.05).
    Results and Discussion Density and dry matter of dominant weed species i.e. Cirsium arvense, Acroptilon repense and Poa trivialis were significantly decreased by herbicide treatments when measured four weeks after spraying. Significant decrease in flower number and/or flower fresh weight of saffron occurred when sprayed with sulfosulfuron, nicosulfuron, 2, 4-D MCPA, metsulfuron-methyl sulfosulfuron, tribenuron methyl, mesosulfuron idosulfuron diflufenican and bromoxinyl MCPA. Furtheremore, these herbicides can not be used for weed control in saffron. Metribuzin, oxadiazon, bentazon, haloxyfop methyl, oxyflurofen, bensulfuron methyl, triasulfuron dicamba and atrazine caused no significant decrease in flower number and/or flower fresh weight of saffron and then can be recommended to use for weed control in saffron fields. In the case of the possible reverse impacts of these herbicides on saffron corms in long-term use, still more studies need to be done. Dry matter of 50-stigmas of saffron flowers were not significantly different among herbicide treatments.
    Conclusions Metribuzin, oxadiazon, bentazon, haloxyfop methyl, oxyflurofen, bensulfuron methyl, triasulfuron dicamba and atrazine caused no significant decrease in flower number and/or flower fresh weight of saffron and therefore can be recommended to use for weed control in saffron fields.
    Keywords: Broadleaf weeds, herbicide injury, herbicide screening, saffron, stigma
  • Mohammadreza Zargaran, Mohammad Jamshidi, Seyed Rostam Mousavi Mirkola Pages 420-432
    Introduction Various pests attack oak trees and in most cases heavily damage them. The European oak leaf roller is one of the important oak pests in some provinces of the Zagros, and it is an important pest of oak forests in some European and North African countries, as well as in Iraq and other regions of Iran. In Iran, it is scattered in the Zagros oak forests, especially in Kohkiluyeh and Boyer Ahmad, Lorestan, Chahar Mahal and Bakhtiari, Fars, and West Azarbaijan Provinces. Repeated removal of oak leaves, particularly by herbivores such as T. viridana in spring, reduces stored photosynthates in trees leading to their decreased diametrical growth.
    Materials and Methods The Ghabre-Hossein region (Piranshahr) was selected as the field operations region because it is one of the most important infestation centers of the European oak leaf roller in the oak forests of West-Azerbaijan. The research was carried out in two consecutive years. Samples of larval instars were taken in early May. Since the sample plot in sampling methods can be points or lines (transects), the four cardinal directions were selected in this study and transects at 100 m intervals were located in each direction.To reduce sampling error, Aleppo (Quercus infectoria) and Lebanon (Q. libani) oak trees were selected for measurements that were similar in appearance and almost uniform with crowns or trunks aligned along the transects. In each studied tree, four suitable branches were selected (one in each cardinal direction), and the number of larvae from the tip of each branch to a length of 50 cm inwards was counted and recorded in forms prepared beforehand. Considering studies that were carried out regarding the biology of the pest, the larvae were counted in mid-May when all larvae were in their last (fifth) instar. In all, 30 Aleppo and 30 Lebanon oak trees were selected in each cardinal direction, and four branches in each direction of these trees were measured. The survey method was used by employing a 25 m rope, a slope gauge, and a compass to locate the sampling transects. SPSS 18 and the 2×4 factorial split plot in time design were used as the statistical method for studying the effects of various cardinal directions and of oak species on abundance of the European oak leaf roller, and Tukey’s HSD test was employed for comparison of the means.
    Results and Discussion This pest has a single annual generation and five larval instars. It overwinters, and spends the entire summer, autumn, and winter, as eggs. Eggs are hatch in late March. Larvae pierce buds to enter into and feed inside them, and large larvae can leave buds and start feeding on other buds. The results showed that in both years the number of leaf-roller moth larvae were more on Q. infectoria in comparison to Lebanon oaks and it seems that oak species (Q. infectoria) is more preferable for the pest to feed upon than Lebanon oaks. Studying populational changes of the oak leaf-roller moth in the geographical directions proved that for both of the tree species the maximum and the minimum number of larvae were respectively in the east and the west in 2014. In 2015, it also became clear that the highest and the lowest frequency of the larvae were respectively in the south and the north. The obtained results confirmed the influence of wind direction on distribution orientation of leaf-roller moth larvae. The number of oak leaf-roller moth larvae significantly increased in 2015 in comparison to the previous year which can be due to the temperature increase in this year.
    Conclusions The number of larvae of the European oak leaf roller on Aleppo oak trees was larger compared to Lebanon oak trees both in 2014 and in 2015, which shows this pest prefers Aleppo oak trees over Lebanon oak trees as its food supply. The number of larvae on both oak species in 2015 was considerably larger compared to the previous year, which may have been caused by increased temperatures in 2015. Study of population changes of the pest in the cardinal directions indicated that the maximum and minimum numbers of larvae on both oak species in 2014 were observed in the eastern and western cardinal directions, respectively, and that the maximum larval concentration occurred in the eastern direction of tree crowns. The dominant wind in the region blew from the southwest, and seemed to be the main reason why larval concentration and distribution occurred in the eastern direction (that was not influenced by wind currents). In 2015 also, the maximum and minimum abundance of larvae were observed in the southern and northern cardinal directions, respectively. Moreover, the largest larval concentration occurred in the northern direction of tree crowns, with the dominant wind in the region blowing in the northeast direction, which demonstrated the direct influence of wind on the orientation and distribution of the European oak leaf roller population. Results obtained in 2014 and 2015 showed that orientation and distribution of the European oak leaf roller can be influenced by wind direction and temperature.
    Keywords: Pest, oak, population, forest, damage
  • Mehdi Mojab, Mojtaba Hosseini, Majid Karimian Klishadrokhi Pages 433-444
    Introduction Johnsongrass (Sorghum halepense (L.) PERS) is one of the most controversial and problematic weed. It is damaging at more than 30 different crops in 53 different countries. S. halepense (L.) is a perennial weed reproducing by seed and rhizome. Since it produces many seeds and rhizomes, it is difficult to control it. A weed germination plays an important role in attaining a prosper establishment in a typical agri-ecosystem; and this trend is adjusted with some environmental factors such as light, temperature, salinity, pH and soil moisture. If you consider the pattern of germination and emergence of weed species, you will able to provide comprehensive information to develop weed management strategies in the future. Thus, the purpose of current research has been to evaluate the breaking methods of the seed dormancy, effect of constant and alternative temperature, light, salinity and drought stress and burial depth on germination and seedling emergence of Johnsongrass.
    Materials and Methods Seeds of Johnsongrass (S. halepense L.) were collected in June 2013 from plants located at the research farmlands of the Agriculture research centre of Fars province in Zarghan town, Iran. Experimental treatments of Breaking Dormancy consist of six level of scarification with 95-98% acid sulfuric (4, 8, 15, 30, 45 and 60 minutes), in the other one, there were the soaked seeds in the water for 24, 48, 72 and 96 hours, and in the next group the seeds were heated in a 95- 98 boiling water for two and five minutes, and again in the next group, for 15, 30, 45 and 60 days, the seeds were chilled in 3 C, and in the last group, the seeds stored in 3 and 12 months after harvest comparing to control treatment. A number of 25 seeds were transferred to incubators to identify a suitable temperature and light regime for subsequent experiments of germination and determine under alternative day/night temperatures (15/5, 20/10, 30/15 and 35/20 C) and constant temperature day/night (5, 10, 15, 20, 25, 30, 35, 40 and 45 C) in both light/dark and dark regimes. The salt and osmotic potentials were applied in -1, -3, -5, -7, -9, -11 levels and control treatment in order to survey the stress of salt, drought on seed germination and to compare both stress on it. NaCl was applied in the Vant Hoff method to influence salt stress and also PEG 6000 was applied in the Michel methods to affect osmotic potential. In the burial depth experiment, a number of 30 seeds, for 30 days, were laid in the depth of 0, 0.5, 1, 2, 3, 4, 6, 8 cm in plastic vases with 15 cm diameters. All experiments were conducted twice in the form of randomized complete-block design with four replications. Each replication was arranged on a different shelf of growth chamber and considered as a single block in the laboratory experiments. The data of the replicated experiments were pooled for analysis, as the time interaction and treatment was absolutely meaningless. A functional three-parameter logistic model Was fitted to the germination values (%) obtained at different concentrations of NaCl or osmotic potential. Also, a sigmoidal decay curve was fitted to show the seedling emergence (%) values at different burial depths.
    Results and Discussion Seed germination was influenced significantly on different treatments of breaking dormancy (Fig 1). Sulfuric acid treatments showed significant difference rather than control treatment. In 30 and 45 min sulfuric acid scarification, germination was recorded more than 95 %. Based on the achieved results it is very probable that the hard seed prevents germination and this issue causes the weed remains stable in seed bank. Germination percentage was not affected by light regime and temperature interaction (both in constant and alternative) (Fig 2a and 2b), the influence of different temperatures on the feature was significant (Fig 2a). The same germination has been seen in all temperatures (both light and light/ dark regime) in all temperature, The more temperature increased, the seed germination increased too. In both regime, at 25/15, 30/20 and 35/25 C (day/night), germination was recorded more than 95 % (Fig 2a). The maximum and the minimum germination percentage of Johnsongrass in light/ dark regime, were accorded in alternative temperature in 30/25 C (99.5%) and 15/5 C (35.5 %) respectively. In constant and alternative temperatures, the germination was similar. In the constant range of 25-45 C temperatures, the feature was occurred more than 90 % (Fig 3a). The maximum and the minimum germination percentage, in light/ dark regime, were recorded in 25 C (99%) and 5 C (0%) respectively (Fig 3a). The experiment on light revealed Johnsongrass seeds was not influential to light, therefore it wasnt photoblastic species and the germination percentage will not exceed through light. The germination percentage could not be decreased by light as a major factor. Accordingly it is reported that Johnsongrass seed was not photoblastic and the light regime had the slightest effect on the number of seed germination. As the matter of fact the temperature has greater importance comparing with light. The deeper the seedling planted, the fewer emergences were accorded. The emergence at the surface of the soil (zero depth) was 83.33% and in depth of 3 cm it was 100%. The minimum emergence for 18.35%, devoted to depth of 8 cm (Fig 5). With an increase in five cm burial-depth, the seedling emergence decreased for 81.65 %. According to the fitted sigmoid model, the depth which caused a decrease for the maximum 50% seedling emergence calculated 5.60 cm. The results showed that weed seedling emergence was limited in depth of 6 cm and over. The decrease in seedling emergence may be linked to seed energy with increasing buried depths. Agronomic practices causing a decrease in seed germination and an increase seed death is able to help the weed management. Our study model proved that 5.60 cm was the depth in which 50% the maximum emergence decreased (Fig 5) and therefore, tillage more than 6 cm could help reducing germination and emergence of this species.
    Conclusions Based on the above results, we come to conclusion that Johnsongrass seed is able to tolerate a variety of environmental circumstances and as soon as providing a suitable condition such as temperature, in particular, it is capable to improve beyond 90% of germination. Salinity and drought stress play no important role in germination. Although, the more increase in depth, the less seedling emergence happens. Consequently one of the best methods of managing this weed is to till the field over 6 cm.
    Keywords: Burial depth, salinity, scarification, light, osmotic potential
  • Mohammad Hajian, Ebrahim Ganji Moghadam, Hamid Afzali Pages 445-455
    Introduction
    The best cherry rootstock for Iranian nurseries and orchards is Prunus mahaleb (L.) Mill. Mahaleb is tolerant to lime-induced iron chlorosis and zinc deficiency. It is a good rootstock on light, calcareous soils and arid climates in Iran but sensitive to Phytophthora. Iran represents a significant source of germplasm of different fruit species, especially for those from the genus Prunus. Collection and research on P.mahaleb was initiated at the Horticultural Department of Khorasan Razavi Agriculture and Natural Resources Research and Education Center in 1997 for mahaleb cherry rootstock. Some researchers have reported pathogenicity of Phytophthora species (Banihashemi and Sartipi, 2004; Wilcox and Mircetich, 1985; Exadaktylou and Thomidis, 2005; Tomidis et al., 2008). This study was conducted to evaluate the susceptibility of 30 selected dwarf Mahaleb genotypes to P.nicotianae, P.citricola, P.cactorum and P. citrophthora under greenhouse and orchard conditions.
    Material and
    Methods
    In this study, the response of 30 selected dwarf Mahaleb genotypes (188, 171, 165, 162, 161, 155, 139, 136, 131, 120, 106, 104, 101, 100, 90, 194, 195, 199, 200, 224, 228, 247 , 249, 265, 266, 267, 268, 270, 272, 277) to disease caused by four species of the fungus Phytophthora root and crown rot were investigated under greenhouse and orchard conditions. Greenhouse experiments were performed based on Ribeiro and Baumer, 1977 and modified it by Feichtenberger et al., 1984. For evaluation the index disease was performed based on the method of Broadbent and Gollnow 1992. Orchard terials was laid out in the Toragh research station in Mashhad. Evaluation of genotypes and contamination based on Tomidis, 2001 was performed by measuring the area of necrosis.
    Results And Discussion
    In evaluating the reaction of young seedling dwarf mahaleb genotypes to four Phytophthora species under greenhouse conditions, results showed that four species of Phytophthora pathogens on all mahaleb genotypes but P.citricola, P.cactorum showed disease severity than P.citricola, P. nicotianae. In response assessment test seedlings in the greenhouse genotypes Mahaleb highest rate of infection to P.cactorum in genotype 277 and the lowest index of disease severity showed in genotypes 100, 188, 199, 200, 224 and 266, respectively. The highest and lowest number of leaves was counted on 199, 272 and 277 respectively. The least and highest shoot dry weight were related to 277 and 100 genotype respectively. The maximum and minimum disease severity to P.citrophthora revealed in 265 and 265, 100, 188, 194, 199 genotypes, respectively. The highest and lowest number of leaves was counted on 188 and 249 respectively. The least and highest shoot dry weight were related to 249 and 100genotype respectively. The least and highest root dry weight was measured on 265 and 100 genotype, respectively. In response assessment test seedlings in the greenhouse genotypes Mahaleb highest rate of infection to P.citricola in genotype 265 and the lowest index of disease severity showed in genotypes 100, 162, 171, 188, 199, 200,224, respectively. The highest and lowest number of leaves were counted on 100and 277, 272 respectively. The least and highest shoot dry weight were related to 272 and 100 genotype respectively. The least and highest root dry weight were related to 277 and 100 genotype respectively. The highest rate of infection to P.nicotianae in 120 genotype and the lowest index of disease severity were related to the genotype of 188 and 199. The highest number of leaves in genotype No.100 and the lowest number of leaves were belonging to genotypes 272 and 277, respectively. The least and highest shoot dry weight were related to 247 and 100 genotype respectively. The least and highest root dry weight were related to 265 and 100 genotype respectively. The results of the assessment of the two year old seedlings mahaleb genotypes under orchard conditions showed that four Phytophthora species had different degrees of disease symptoms. Phytophthora species in their ability to create the symptoms are different. The lowest level of necrosis is created by P.cactorum. The highest and lowest levels of necrosis of P.cactorum were measured in 267 and 162 genotypes, respectively. In P. citrophthora, the highest and lowest levels of necrosis were measured in 277 and 188 genotypes, respectively. The highest and lowest levels of necrosis of P. nicotianae were measured in 272 and 188 genotypes, respectively.
    ConclusionThe results of the assessment Mahaleb genotypes to four species of Phytophthora in the orchard showed that the lowest level of tissue necrosis in genotypes of 106, 139, 162, 188, 195, 224, 266 and 270, respectively. Finally our results revealed that P.citricola, P.cactorum were pathogenic Phytophthora species and three mahaleb genotypes (266, 224 and 188) had highest potential resistance to P. nicotianae, P.citricola, P.cactorum and the P.citrophthora respectively.
    Keywords: Mahaleb, Chreery, Phytophthora, Root, Crown rot
  • Elham Elahifard, Narges Shamshirgarzadeh, Alireza Abdali Mashhadi, Mohammad Reza Moradi Telavat Pages 456-465
    Introduction Negative and positive cross-resistance to other herbicides have been found in triazine-resistant biotypes. Thus, negative cross-resistance has been reported to bentazone for Brassica napus L. and A. retroflexus L., and to pyridate for B. napus and Epilobium ciliatum Raf.. In contrast, positive cross-resistance to bentazone has been found in Chenopodium album L. and Solanum nigrum L.. Negative cross-resistance, i.e., herbicide-resistant plants being more sensitive to herbicides than susceptible plants, has been documented in several triazine-resistant weed biotypes. The goal of this study was to search for herbicides that exert negative cross-resistance at the whole-plant level for control of atrazine-resistant populations of E. colona.
    Materials and Methods Suspected resistant and susceptible seeds of junglerice to atrazine were collected from sugarcane fields and adjacent areas of Karun Agro-Industry Inc., Shushtar, southwestern of Iran in 2014 - 2015 growing season. These populations were named according to their population status and abbreviated as follows: R1, R2, R3 and S (susceptible population). All the collected seeds (R- and S-populations) were stored at room temperature (25 oC). Herbicides were tebuthiuron, linuron, diuron and diuron hexazinone. For the PRE application, 10 seeds were planted in 500-ml plastic pots containing clay:sand mix, and herbicides were applied using an flood nozzle and back sprayer calibrated to deliver 350 L ha-1 to the suspected resistant and susceptible junglerice biotypes 1 d after sowing. Plants were thinned to 4 plants per pot. The aboveground biomass was harvested 28 DAT, dried at 75 °C for 48 h, and weighed. The aboveground biomass data were expressed as a percentage of the untreated control. The experiment was a completely randomized block design with four replications and was repeated. The data were analyzed using a nonlinear regression model and R software (drc add on packeges), the three and four parameters log-logistic equation was fitted to the data to describe the responses of the populations to herbicides: susceptible population was estimated as an index in order to compare the resistance levels of the tested populations.
    Results and Discussion The result of screening test showed that 3 populations were resistant to atrazine. The results of dose-response assay using atrazine revealed that resistance factor of R1, R2 and R3 populations were 12.26, 6.59 and 3.75 based on wet weight (% of control) and 5.37, 4.22 and 4.71 based on number of survival plants (% of control), respectively. The ED50 values of the R1, R2 and R3 populations were 36.85, 73.01 and 41.71 g ai ha-1 compared with 44.42 g ai ha-1 of the S-populaton of tebuthiuron. The Rf of the R1, R2 and R3 populations were 0.80, 1.53 and 0.72 of tebuthiuron, respectively. The ED50 values of the R1, R2 and R3 populations were 92.76, 107.73 and 106.84 g ai ha-1 compared with 152.51 g ai ha-1 of the S-populaton of linuron. The Rf of the R1, R2 and R3 populations were 1, 1.89 and 3.26 of tebuthiuron, respectively. The ED50 values of the R1, R2 and R3 populations were 74.21, 95.25 and 69.80 g ai ha-1 compared with 79.03 g ai ha-1 of the S-populaton of diuron. The Rf of the R1, R2 and R3 populations were 0.97, 0.85 and 1.18 of diuron, respectively. The ED50 values of the R1, R2 and R3 populations were 62.11, 49.48 and 54.30 g ai ha-1 compared with 88.72 g ai ha-1 of the S-populaton of diuron藬嫎⧨. The Rf of the R1, R2 and R3 populations were 0.62, 0.68 and 0.52 of diuron藬嫎⧨, respectively. The results showed that negative cross resistance to tebuthiuron, linuron, diuron and diuron hexazinone. Resistant biotypes, also, showed the highest negative cross resistance to diuron藬嫎⧨.
    Conclusions Some herbicides that inhibit photosystem II bind more efficiently to the mutant triazine binding domain than to the wild (susceptible) type. Triazine-resistant weeds frequently show negative cross-resistance to other photosystem-II inhibitors, such as bentazon and pyridate; triazine-resistant weeds can also exhibit negative cross-resistance to herbicides that do not affect photosystem II. Negative cross resistance may be the major reason that atrazine resistance did not evolve where herbicide mixtures were used, when the mixed herbicide (usually a non-PS II inhibiting acetanilide) also controlled triazine-sensitive weeds. The value of negative cross-resistance linked with the general lack of fitness of almost all triazine-resistant weeds may be greater than we measured herein. The competition exerted by a crop in the field may further accentuate and exacerbate the lack of fitness and further lower the RI.
    Keywords: Dose-response, mixed herbicides, phenyl urea herbicides
  • Namdar Moradi, Heshmatollah Rahimian, Ali Dehestani, Valiollah Babaeizad, Yaser Yaghoubian Pages 466-474
    Cucumber is one of the economically important vegetables in Iran which is extensively attacked by powdery mildew. Identification and application of disease resistant genotypes is an efficient method to escape the disease epidemic. A number of 23 greenhouse and field cucumber cultivars were evaluated and screened for powdery mildew resistance and putative resistant cultivars were identified based on percent Disease Index (PDI) measurement. In addition, leaf chlorophyll fluorescence was measured and analyzed in 5 cultivars selected from resistant, semi-resistant and sensitive groups. Based on the results of PDI measurements, a considerable variation between the cultivars was observed so that the cultivars classified to four groups including resistant, semi-resistant, semi susceptible and susceptible. Two greenhouse cultivars i.e. CLE and Green Magic with the PDIs of 7.78 and 8.33 were the most resistant and the two field cultivars Beit Alpha and SuperN3 with the PDIs of 31.11 and 31.67 were the most susceptible cultivars. Based on the ANOVA of chlorophyll florescence parameters, a significant infection effect on minimal florescence (Fo), variable florescence (Fv) and vitality index (Fv/Fm) and a significant genotype effect on Fo parameters was observed (P
    Keywords: Cucumber, powdery mildew, photosynthesis, photosystem II, vitality index
  • N. Helalat, Mehdi Nasresfahani, M. Olia Pages 475-487
    Effect of Organic Manure on Sugar Beet Cyst Nematode Population Densities of Heterodera schachtii Schmidt 1871
    Introduction. Sugar beet cyst nematode (SBCN), Hederodera schachtii Schmidt. 1871, marked as one of the most damaging disease of sugar beet worldwide. It's also an important disease of sugar beet in Isfahan Province, and causing plenty of an irreversible damage. Thus, the nematode infested fields for cultivation in the province and the country 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 hosts, which have been identified and introduced so far. The SBCN management's strategies are a long term crop rotation, use of catch crops, early planting and the use of nematicides. In general, the best method reported to control SBCN is a 3 to 7-year rotation with non-host plants. In addition, incorporation of farm manure into the soil had a positive effect in controlling potato golden cyst nematode. Testing on vermicomposting and non-organic fertilizers revealed that, free-living nematodes in the population index were highest in the vermicompost treatments than non-organic fertilizers.
    Materials and methods. The initial population of SBCN in the infested soil was determined, before the treatment of the selected field. Then, 200 g. of soil were selected, out of several samples collected from every plots, which was air dried and in the file system using Fenwick, the cysts were extracted. Eggs and the second larvae in the soil and end up in a 200 g. of soil were calculated accordingly. All the organic matters, including, poultry manure at 10, 20 and 40 t/ha compost fertilizer by municipality of Isfahan wastes, vermicompost, waste cabbage leaves and farm manure (cow manure) were employed. Reproductive factors and the percent decrease and or increase in SBCN populations in each treatment were calculated relative to the initial population of the same treatment. And, comparison of means was done by Duncan tests. For the Greenhouse experiments, the same treated soils from each and every treatment in field were poured into the clay pots with a capacity of 5 kg of soil. At the time of harvest, the produced beets in each and every plot were weighted, and the beet samples for determining of sugar percentage and the important elements were sent to sugar factory for analyzes. The analysis of variance was performed, using SAS software and comparison method.
    Results and ddiscussions. The initial population of SBCN was 4.85 eggs and larvae per gram of soil, before the implication of the treatments in the field. There were 92.40 and 88.44 percent reduction in SBCN final population for the poultry manure at the rate of 40 and 20 tons per hectare, with the high significant effect, in comparison to other ones respectively. Variance analysis of Reproduction factor showed that there is a significant difference between the treatments. Poultry manure 40 t/h with 0.14 eggs and larvae per gram of soil was the lowest one in reproduction factor, with a high significant effect to other treatments and control groups. Followed by poultry manure 20 t/h, compost 015, 60 ha, poultry manure 10 t/h and compost 08, 60 t/h, in the next category with a significant effect. The results on the yield, sugar content and other indices showed significant differences between the various treatments. Poultry manure 20 and 40 t/h, with the yield of 27.55 and 26.93 t/h, in a statistical group had the maximum amount of product with a very minor difference, were the most effective treatments on the assessed factors, including final population, reproduction, multiplication rat and reduction percentage in SBCN, H. schachtii compared to other treatments and the checks. In this regard, it has been shown on other nematodes that, chicken manure has reduced the population of M. incognita, Hoplolaimus columbus and Pratylenchus penetrans in brinjal. And also the use of chicken manure on control of root-knot nematodes was very effective and even caused IGR in tomato production.
    Conclusion.1- It was found that, the use of organic matters, chicken manure, municipal compost, vermicompost; waste cabbage leaves and farm manure in different amounts control the SBCN population accordingly.
    2- Therefore, it is suggested here, that chicken manure at 20t/ha, is for an optimum use and economically reasonable and significant amount for the SBCN control.
    3- Also composts 015 and 08, vermicompost, farm manure and waste cabbage leaf at 40 to 60t/h, in terms of economic value appears to be applicable.
    4- Always a method or a substance, in terms of its own hazards is not recommended. Therefore, any of the said material can be used in intervals for SBCN control and or in integration with other methods such as crop rotation, disease scape,
    Keywords: Farm, poultry manure, compost, vermicompost, cabbage leaves, compost
  • Seyyed Alireza Esmailzadeh Hosseini, Mahmod Dehghany Ashkezary, Mostafa Abedi-Tizaki Pages 488-495
    Madder is one of the most important crops that used for medical and industrial applications and is widely cultivated in Yazd province. During 2012, sampling was done form seeds madder in important areas planted in Yazd province, including Bafq and Ardakan. After culturing and purification of fungal isolates in PDA and CLA media, additional identification was performed by PCR with specific primers for each species. Detection of fungi mycotoxins producing potential such as Nivalenol (NIV) using Tri13 primers was done. High-performance liquid chromatography (HPLC) was used to confirm the produce NIV mycotoxins potential in Fusarium species. 249 fungal strains were isolated from madder seed belonging to 6 genera of fungi including Fusarium spp., Aspergillus spp., Penicillium spp., Alternaria spp., Rhizoctonia solani and Rhizpous spp., that Fusarium isolates with 71 percent was the most frequency among fungi isolated. Among Fusarium fungi isolated, F. solani (55 isolates) and F. oxysporum (41 isolates) were the most frequency. F. poae, F. semitectum and F. equiseti ability to produce mycotoxins such as Nivalenol (NIV) that are harmful to human health and animals as well as effect on the quantity and quality of madder color production. Tri13 gene involved in production NIV was detected in three Fusarium species that all isolates produce NIV. The results of HPLC showed that all studied Fusarium fungi, have the potential to produce NIV mycotoxins. The results of this study showed that fungi associated with seeds madder are able to produce trichothecene mycotoxins that they can be dangerous for consumers. Given that, this is the first report of fungi mycotoxins producing on seeds madder in Yazd province, thus should be measures to control and reduce fungal agents in these products.
    Keywords: Mycotoxin, Rubia tinctorum, Yazd
  • Maryam Pahlavan Yali, Mohsen Mohammadi Anaii Pages 496-504
    Introduction
    Wheat (Triticum aestivum L.) is the most principal plant food for 35 percent of the world's population, and canola (Brassica napus L.) is one of the most important brassicaceous crops that play a major role in the development of edible oil. The greenbug, Schizaphis graminum (Rondani) and cabbage aphid, Brevicoryne brassicae (L.) are the main pests of wheat and canola, respectively, which can considerably limit profitable production of these crops either through direct feeding or via transmission of plant pathogenic viruses. Although chemical control is the most effective and easiest way to control aphids, but this method causes problems such as pesticide residues in food and environment, and development of resistance to insecticides. The utilization of plant extracts is an environmentally safe method that can be used in control of these aphids. Among these, the products of the Melia seed (Melia azedarach Linnaeus) and lemon peel (Citrus limonum Risso) can be noted. Negative associations between phenolic compounds present in plant species and aphid’s invasion have been recorded for some aphid species. In this study, our goal was to determine the amount of phenol in plant extracts of Melia seed and lemon peel and evaluate the toxicity of these compounds on the wheat aphid and cabbage aphid in various doses after different time periods.
    Materials And Methods
    This research was conducted in a growth chamber (temperature 25 ± 1˚C, 65± 5% RH and a photoperiod of 16L: 8D). S. graminum and B. brassicae were bred on wheat (Pishtaz cultivar) and canola (Hyola401 cultivar), respectively. The extraction of Melia seed and lemon peel was carried out and then contact toxicity bioassay was done to evaluate the insecticidal effects of these extracts on nymphs of wheat and cabbage aphids using a completely randomized design. The leaves of wheat and canola plants, impregnated with three different concentrations of each extract (10, 50 and 80 g/ml) and dried. Thereafter the leaves were individually placed on agar gel 7.0% in Petri-dishes with a diameter of 6 cm. Then same age nymphs of wheat and cabbage aphids were separately released in Petri-dishes (20 aphids in each Petri-dish), and the number of dead nymphs was recorded after 12, 24 and 36 hours. This experiment was performed in three replicates for each treatment. Furthermore, the amount of phenolic compounds in two extract samples (Melia seed and lemon peel) was determined by Folin ciocalteu method, and the absorbance was measured at 725 nm using a spectrophotometer. The lethal effects of two tested extracts for each of aphid species (in each tested concentration and time period) were analyzed using T-test in SPSS v22 software. Variables of the mortality percent in three different concentrations and amount of total phenolic were evaluated using the one-way analysis of variance in SPSS. The comparison of differences between treatments means was done using Tukey’s test (P
    Keywords: concentration, phenol, plant secondary metabolite
  • Mohammad Vali Taghaddosi, Mohammad Rahim Moeini, Gholam Ali Akbarzadeh Shokat, Hashem Kamali, Raoof Koliaei Pages 505-510
    Codling moth, Cydia pomonella L. is the key pest of apple in Iran. Due to inefficiency of other control measures, insecticide application has been the first option, most common and successful management method so far. In this research, effect of Diflubenzoron (Dimilin® SC48) was compared with Phosalone (Zolone SE 35) and Thiaclopride(kalipso® SC480) in three regions of Zanjan, Urmia and Bojnord using a layout of RCBD with 4 replications for one growing season. Results showed that treatment of Dimilin.with 4.02±0.23, 7.26±1.4, and 2.6±0.42 percent of infection at Urmia, Zanjan and Bojnord recorded the least percent of infection respectively whereas treatment of control with 57.37±4.94, 45.21±3.3 and 57.12±3.08 percent of infection at the same experimental points recorded the highest percent. Treatment of Kalipso with 1.02±0.43 and 3.00±0.44 percent of infection at Urmia and Zanjan and treatment of Zolon at Urmia with 3.65±0.29 registered the same statistical group as the Dimilin. It could be concluded that current insecticides may be replaced by Dimilin per need.
    Keywords: Phozalone, Thiaclopride, Chemical contro, Codling moth
  • Marjan Seiedy, Mahdi Tork Pages 511-517
    IntroductionThe predator Amblyseius swirskii and entomopathogenic fungus Beauveria bassiana are important biocontrol agents of Trialeurodes vaporariorum. Determination of the host preference of predators in the fields when receiving signals related to either untreated and Beauveria bassiana-treated pest is important.
    Materials and MethodsIn this research, the prey preference of adult female (2 days old) of A. swirskii was determined on untreated and Beauveria bassiana-treated of Trialeurodes vaporariorum (Homoptera: Aleyrodidae) in various treatments base on Manly Index. These different treatments consisted of two time intervals; 24 and 48 h post-inoculation of greenhouse whiteflies with 1×105 conidia /ml of B. bassiana with 13 replicates. 24-h starved predators were added to the leaf discs singly then the number of consumed untreated and B. bassiana-treated T. vaporariorum in each Petri dish was assessed after 24 h.
    Results and DiscussionThe results revealed that mean number of consumed B. bassiana-treated T. vaporariorum in two time intervals; 24 and 48 h. after inoculation were 4/15±0/19 and 2.23±0/12, respectively. This investigation showed a significant preference of A. swirskii towards untreated T. vaporariorum in 24 (P
    Keywords: Amblyseius swirskii, Entomopathogen, greenhouse whitefly, prey preference
  • S. Sarani, S. Gh. Moosavi Pages 518-526
    Introduction Weed control is an essential part of all crop production systems. Weeds reduce yields by competing with crops for water, nutrients, and sunlight. Weeds also directly reduce profits by hindering harvest operations, lowering crop quality, and producing chemicals which are harmful to crop plants. Plant density is an efficient management tool for maximizing grain yield by increasing the capture of solar radiation within the canopy, which can significantly affect development of crop-weed association. The response of yield and yield components to weed competition varies by crop and weeds species and weeds interference duration. The objective of the present study was to evaluate the effect of weed interference periods and plant density on the yield and yield components of sorghum.
    Materials and Methods In order to study the effect of plant density and weeds interference on weeds traits, yield and yield components of sorghum (Var. Saravan), an experiment was conducted as in factorial based on a randomized complete block design with three replications at the research field of Islamic Azad University, Birjand Branch in South Khorasan province during year of 2013. Experimental treatments consisted of three plant density (10, 20 and 30 plants m-2)) and four weeds interference (weed free until end of growth season, interference until 6-8 leaf stage, interference until stage of panicle emergence, interference until end of growth season). Measuring traits included the panicle length, number of panicle per plant, number of panicle per m2, number of seed per panicle, 1000-seed weight, seed yield, biological yield, number and weight of weeds per m2. Weed sampling in each plot have done manually from a square meter and different weed species counted and oven dried at 72 °C for 48 hours. MSTAT-C statistical software used for data analysis and means compared with Duncan multiple range test at 5% probability level.
    Results and Discussion Results showed that all measured traits except seed yield were significantly affected by plant density. Although the increase in plant density from 10 to 30 plants m-2 significantly decreased panicle number per plant, number of seed per panicle and 1000-seed weight by 45.5, 16.2 and 12.3%, respectively but significantly increased number of panicle per m2 by 54.3%. This subject caused seed yield did not show significant changes as plant density per area unit was changed. Also, means comparison showed that increase in density from 10 to 30 plants m-2 had positive significant effect on biological yield so that its increased by 56.7%. Interference treatment had significant effect on all measured traits except number of panicle per plant. Traits of 1000-seed weight, seed yield and biological yield decreased considerably by extending of weeds interference period and the highest seed yield with 350.04.37 g. m-2 achieved in treatment of weed free until end of growth season which were 18.9, 47.6 and 73 percent more than interference until 6-8 leaf stage, interference until stage of panicle emergence, interference until end of growth season, respectively. Also, weed interference until the end of growing season of sorghum reduced biological yield by 59.9 percent compared to treatment of weed free until end of growth season. The highest weed density with 182 plants per m2 was observed in interference until 6-8 leaf stage and weed density per unit area reduced by increase in interference period. Despite the declining in weed density, weeds dry weight per m2 was increased by increasing interference period until the end of growth season. On other word, weeds were in early development, with high density and low dry mass accumulation, which are desirable from a technical point of view for weed control.
    Conclusions This research showed that increase in plant density non significantly increased on seed yield but change of density from 10 to 30 plants m-2 had positive significant effect on biological yield. Moreover, presence of weeds in farm of grain sorghum is inhibitor factor for maximum production. Weed interference decreased seed and biological yields of sorghum by decline in yield components and tillering. Given that Saravan variety is a plant of double purpose (grain and forage) can be suggested density of 10 plants per m2 and weed free until the end of growth season treatment for sorghum (Var. Saravan) cultivation in Birjand region. Also, evaluation of higher densities of sorghum (Var. Saravan) and early season interference can be recommended for subsequent studies.
    Keywords: density, panicle, sorghum, weed interference, yield components
  • Hoda Salehipour, Hassanali Vahedi, Naser Moeininaghadeh, Abbas Ali Zamani Pages 527-539
    Introduction Tomato, Lycopersicon esculentum Miller has a special place among agricultural products. A wide range of pests and diseases are causing damage to tomato. Tomato fruit worm, Helicoverpa armigera (Hubner) 1809 and beet armyworm, Spodoptera exigua (Hubner) 1808 are two important pests of the Lepidoptera order, which aggress to the tomato. Biological control by predators and other natural enemies is an important components of a comprehensive pest management program (IPM). Among the natural enemies, parasitoids has special significance and can be used in biological control of pest plants. Habrobracon hebetor Say (Hymenoptera braconidae) is a cosmopolitan, gregarious, ectoparasitoid that attacks the larval stage of several species of Lepidoptera and is considered one of the best potential biological control agent. Study of pest density on different cultivars has an important role in choosing appropriate method and time control, and is basis of plant restance. Therefore in this study mentioned pest density and efficiency of h. hebetor was assessed.
    Materials and Methods Population density and larval parasitism by H. hebetor was examined on twelve tomato varieties including, Rio fujio, AB2, Mariana, Gem pride, King ston, Super queen, 9704, 9706, 9553 and PS 6515 in field conditions during 2014. All experiments were conducted in a randomized complete block design. Five weeks after transplanting, sampling performed randomly. At three-days intervals, egg, larvae and parasitized larvae of each moth were collected on different cultivars of tomato. The whole of each tomato plant were checked for the presence of pests and the number of eggs. 400 and 570 wasps were released in two steps in june 24th and july 23th during 2014, respectively. Number of healthy and parasitized larvae of each pest were counted and recorded to calculate the parasitism percentage. The trichomes density of defferent varieties of tomato was assessed by a stereo microscope with a magnification of 70. The density of trichomes in the leaves after the terminal bud per plant (per square millimeter) were counted and recorded at three points around the midrib. Statistical analysis of data was carried out using Exel 2013 and SPSS 18.0 software.
    Results and Discussion The results of the study showed that the pest density had no significant differences among different cultivars of tomatoes, while there were significant differences in different dates of sampling. The highest density of tomato fruit worm and beet armyworm larvae was observed on AB2 and Kingstone, respectively, while the lowest density of these larvae was obtained on the Kingstone and 6515 respectively. Also, the highest density of h. armigera was in 17 and 22 july 2014 that coincided with the ninth and tenth weeks after transplanting in the field. Parasitism percentage of tomato fruit worm and beet armyworm was significant among different dates of sampling but no significant differences were observed among different cultivars. The highest parasitism percentage of tomato fruit worm larvae was obtained in 22 and 27 july 2014. The highest density of pest was occured in 24 and 27 June and 3 July 2014 coincides with the sixth and seventh tomato growth. The highest larval parasitism of beet armyworm was observed in 17 July 2014, three weeks after bracon release. Study on tomato leaf trichomes density in different varieties with highest and lowest population of tomato fruit worm larvae indicated that, the highest density was observed in Kingston variety. Biological and behavioral differences of tomato fruit worm and beet armyworm are could be effective on host preference by these pests, in addition chemical compounds produced by different varieties of tomato (repellents and attractants) are effective on host selection for oviposition and influence pest population.
    Conclusions Release of parasitoid wasp, H. hebetor to control the larvae of the tomato fruit worm and beet armyworm, plays an effective role as a biological agent and can be used in a management program of theses pest. According to the text, due to the compatibility of resistant cultivars with other control methods and environment, more study on the role of trichomes in plant resistance is recommended to introduce a resistant cultivars of tomato to mentioned pests.
    Keywords: Beet armyworm, Kermanshah, Parasitism, Tomato fruit worm, Tomato varieties
  • Asghar Samiei, Mohsen Mehrvar, Mohammad Zakiaghl Pages 540-547
    Beet black scorch virus(BBSV) is a new soil-borne virus reported from sugar beet fields around the world that in terms of having similar symptoms (root beard) with Beet necrotic yellow vein virus and Probably some mutual interaction with that has high economic importance. For investigation of BBSV distribution in Iran's sugar beet farms a total of 309 samples were collected. Evaluation of test samples with RT-PCR indicated that 147 sample in total (48%) are infected. BBSV also has a satellite that in 30 cases (10%) of the samples was detected. According to this BBSV were detected in sugar beet farms of Khorasan Razavi, North Khorasan, South Khorasan, Lorestan, Ardabil, East Azarbayjan, West Azarbayjan, Ghazvin, Hamedan, Kerman, Kermanshah and Zanjan Provinces. Five isolates for assessment of genetic diversity were selected based on geographical distribution and symptoms in greenhouse including West Azarbayjan, Hamedan, Khorasan Razavi(Mashhad), North Khorasan(shirvan) and Kermanshah. Two important parts including Coat protein and 3'UTR of these isolates were compared with Chinese –N and US –Co isolates. Sequence analysis indicated that Us and Chinese isolates are more resemble together than to Iranians. Resemblance of Iranian isolates to Chinese and US isolates were about 88% in both parts. Iranian isolates were resemble together 98-99%. Only North Khorasan (Shirvan) isolate with less identical batch was separated. It seems that differences in 3'UTR are not effective and in all isolates virus genome well-expressed and translated. But amino acid changes in CP specially N-terminal area are effective in symptoms inducing and interaction with other soil-born Vieruses.
    Keywords: BBSV, Iran, PCR, Beta vulgaris