کنترل کنه تارتن دو‌لکه‌ای در مزارع سویا با کلرفناپیر (پیتون ®) اس‌سی 36 %

کنه تارتن دو لکه ای از مهمترین آفات مزارع سویا است. این پروژه در مزارع سویا استان های اردبیل (مغان) و گلستان با 6 تیمار و 4 تکرار شامل آفت کش های کلرفناپیر (پیتون®) اس سی 36% با غلظت 0.4 و 0.5 در هزار، پروپارژیت (اومایت®) ای سی 57% و بروموپروپیلات (نئورون®) ای سی 25% با غلظت 1 در هزار، هگزی تیازوکس (نیسورون®) ای سی 10 % با غلظت 0.75 در هزار و تیمار شاهد (آب پاشی) انجام شد. تعداد کنه‌های فعال یک روز قبل از سم پاشی، سه، هفت، 14، 21 و 28 روز بعد از سم پاشی در برگ های بالایی، میانی و پایینی بوته سویا شمارش شد. تجزیه آماری توسط نرم افزارsas  در قالب تجزیه مرکب طرح بلوک های کامل تصادفی در دو مکان صورت گرفت. در هر دو منطقه کلرفنا پیر از روز سوم در کنترل کنه تارتن دولکه ای موثر بود. در مغان کارایی در صورت کاربرد کلرفناپیر با غلظت 0.5 در هزار بین 83 - 86% بوده است و در غلظت 0.4 در هزار هم بین 72 - 84% بود، در گلستان کارایی 100 درصد بوده است. روز هفتم بعد از سم پاشی کارایی این ترکیب، در غلظت 0.4 در هزار بین 68 - 72% و در غلظت 0.5 در هزار بین 78 - 94 % در مغان است و درگلستان کارایی 100درصد بوده است. تعداد کنه تارتن در برگ های پایینی بیشتر از برگ هایی میانی و بالایی بوته سویا بود، اما بعد از کاربرد آفت کش ها اختلاف معنی دار نبود. با پایش مزرعه به خصوص در مناطق حاشیه ای، در صورت خسارت 10 تا 15 درصدی بایستی کنترل انجام شود. به کارگیری غلظت مصرفی 0.4 در هزار این کنه کش را برای کنترل کنه تارتن دولکه ای در مزارع سویا با محلول‌ پاشی جامع روی تمامی قسمت های مختلف بوته سویا توصیه می شود.

The Control of Two-spotted Spider Mite in Soybean Fields with Chlorfenapyr (Payton®) 36% SC

Background and Objectives The twospotted spider mite, Tetranychus urticae Koch is one of the most important pests of soybean fields. This mite is one of the most important and harmful pests of soybeans in hot and dry summers, which often begins to cause damage at the end of the growing stage and the beginning of the reproductive stage of plants. Damaged leaves turn yellow and brown and fall off prematurely. The severity of the damage of this pest is greater when the distance between the plants is short and irrigation is not enough. This mite feed on soybean leaves and cause injury by sucking contents out of leaf cells. In severe infestations, infested leaves will turn yellow to tan, or sometimes bronzecolored, and may drop off plants. Infestations can reduce yield. In most cases, the use of acaricides is the only way to control this pest. The use of new acaricides while avoiding their resistance is important for plant mites control.Materials and Methods The present study was conducted in soybean fields of Golestan and Ardabil provinces (Moghan) with 6 treatments and 4 replicates. Treatments were, including clorfenapyr (Payton®) 36% SC  0.5 ml/L (recommended dose), clorfenapyr (Payton®) 36% SC  0.4 ml/L, propargite (Omite®) 57% EC 1 ml/L (recommended dose), bromopropylate (Neuron®) 25% EC 1 ml/L (recommended dose), hexythiazox (Nissorun®) 10%EC 0.75 ml/L (recommended dose) and a control treatment by spraying water. Mean number of mites per leaf was counted one day before and 3, 7, 14, 21 and 28 days after spraying in three floors of plant (bottom, middle and top of plant).The percentage of efficiency was calculated by the HendersonTilton method. Statistical analyses were done using SAS software with randomized complete block design in multiple spaces. Data analysis and comparison of means were performed using Tukey test.Results The efficacy of studied acaricides was acceptable in all three floors. In Moghan and Glostan province, before spraying on the lower, middle and upper leaves of soybean plants, the number of T. urticae mites counted per leaf in different treatments did not differ significantly. Clorfenapyr (Payton®) was effective after 3 days. The percent mortality of mites when were treated with clorfenapyr (0.5 ml/L) in the upper, lower and middle floors was 8386% in Ardabil province, although has been reported 7284% for Payton (0.4 ml/L). While in Golestan province, it has been 100%. The efficacy of the compound was 6872% (0.4 ml/L) and 7894% (0.5 ml/L) in Ardabil province (Moghan) and was 100% in Golestan province after 7 days. The knock down effect of this acaricide compared the others was significant. The efficacy of the compound was up to 99% (Ardabil province) and 96% Golestan province after 28 days that indicated the persistence of these acaricides. The results showed that twospotted spider mite on the lower leaves in both provinces showed more infection. However when used pesticides, it did not show any significant differences. The percentage mortality of mites in Moghan were reported for Payton (0.4 ml/L) (86.32 ± 2.75%, 83.61 ±7.21%), (78.49 ± 4.01%, 82.87 ± 4.58%), (93.52 ± 1.47%, 74.80 ± 9.91%), (95.12 ± 3.90%, 80.39 ± 3.54%) and (99.33 ± 0.67%, 84.82 ± 8.29%) respectively after 3, 7, 14, 21 and 28 days in lower leaves, while the percentage mortality of the spider mites when treated with Payton (0.5 ml/L) after  3, 7, 14, 21 and 28 days  were 100 ± 0%, 100 ± 0 %, 94.94 ± 5.05%, 100 ± 0% and 93.95 ± 4.72% and for Payton (0.5 ml/L) were 100 ± 0%, 100 ± 0%, 88.80 ± 8.57%, 95.02 ± 2.87% and 85.51± 4.92% in lower leaves in Glostan province.Discussion It is recommended to use chlorfenapyr acaricide with Payton brand due to high shortterm effect (three days after spraying) and duration of action up to 28 days after spraying to control twospotted spider mite in soybean fields. These compounds showed acceptable efficacy in controlling twospotted sider mites on soybean fields. In most cases, the application of the two concentrations of the clorfenapyr was not significantly different, but the percent mortality was more when it treated with 0.4 ml/L. The number mites in lower floors of soybean was more than the upper and middle floors, but after the application of this pesticides was not significantly different. Based on these results, we recommend the 0.4 ml/L dose of clorfenapyr (Payton®) for the control of twospotted spider mite in soybean fields.