اثر تنش شوری بر میزان اثرات باقیمانده علف‌کش اولتیما بر گیاه گندم تحت شرایط گلخانه‌ای

نوع مقاله: مقاله پژوهشی

نویسنده

عضو هیات علمی گروه مهندسی تولید و ژنتیک گیاهی ، دانشگاه شهید چمران اهواز، اهواز، ایران

10.22055/agen.2020.32704.1561

چکیده

افزایش پایداری علف‌کش‌ها در خاک ممکن است به اندازه‌ای باشد که به گیاهان زراعی در تناوب‌های بعدی خسارت وارد نماید. ویژگی‌های خاک می‌توانند بر پایداری علف‌کش‌های پیش‌رویشی و پس‌رویشی که به نحوی به محیط خاک وارد می‌شوند، تأثیر بسزایی داشته باشند. لذا آزمایشی گلدانی در قالب فاکتوریل در طرح پایه کاملاً تصادفی در 3 تکرار با تیمارهای آزمایشی شامل شوری خاک در دو سطح غیر شور (5/2 دسی‌زیمنس بر متر) و شور (6 دسی‌زیمنس بر متر) ، مقدار علف‌کش در 4 سطح (شامل 0، 25، 50 و 100 درصد مقدار توصیه شده) و زمان کاشتدر دو زمان 60 و 120 روز بعد از کاربرد علف‌کش نیکوسولفورون به همراه ریم‌سولوفورون (اولتیما) با در نظر گرفتن گیاه گندم به عنوان گیاه آزمایشی (در مجموع در 48 واحد آزمایشی) در دانشگاه شهید چمران اجرا شد. بر اساس نتایج، افزایش سطح کاربرد علف‌کش باعث کاهش سطح ویژگی‌های رشدی گیاه گردید. در تیمار 60 روز کاشت پس از کاربرد علف‌کش، وزن خشک در تیمار کاربرد 100 درصدِ مقدار توصیه شده علف‌کش در شوری 5/2، برابر با  6/1 گرم می‌باشد که اختلاف معنی‌داری با تیمار 50 درصد کاربرد علف‌کش در شوری برابر با 6 دسی‌زیمنس بر متر نداشت. لذا در شوریِ بیشتر، سطح کمترِ کاربرد علف‌کش می‌تواند به اندازه‌ی سطوح بالاتر علف‌کش در شوری کمتر به گیاه آسیب وارد نماید. با افزایش زمان کاشت اثرات باقیمانده علف‌کش در خاک کاهش یافت. کاشت گیاه 120 روز بعد از کاربرد 25 درصد علف‌کش، اثرات آن را کاملاً خنثی کرده به نحوی که تفاوت معنی‌داری با سطح عدم کاربرد علف‌کش مشاهده نمی‌شود. لذا می‌توان نتیجه گرفت با انتخاب زمان صحیح می‌توان اثرات مخرب مصرف مقادیر بیشتر علف‌کش را تا حد زیادی کاهش داد. همچنین در نظر گرفتن ویژگی‌های شیمیایی خاک از جمله شوری به عنوان عامل تأثیرگذار بر رفتار علف‌کش‌ها در خاک می‌تواند در کنترل آثار باقیمانده علف‌کش‌ها در خاک و گیاه مؤثر واقع شود. در صورت وجود املاح اضافی در خاک (شوری) و کاربرد حداقل 50 درصد مقدار توصیه شده علف‌کش اولتیما، بهتر است حداقل 120 روز فاصله زمانی کاشت برای گیاه گندم در تناوب زراعی رعایت شود.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of salinity of soil on residual effects of ultimo herbicide on wheat growth under greenhouse conditions

نویسنده [English]

  • Ali Monsefi
Assistant professor, Plant Production Engineering and Genetics Department. Faculty of Agriculture, Shahid Chamran University of Ahvaz, Iran.
چکیده [English]

Introduction Herbicides are chemicals that are used to inhibit the growth or to eliminate weeds in agricultural fields to increase the yield of crops in crop production. By the end of the 19th century, with the increasing labor supply problems, the need for chemical methods to control weeds became apparent. It was first reported in France in the 1980s, that sulfuric acid was used in the fight against weeds in sugar beet fields. Nowadays, most of the herbicides used are organic herbicides, which share organic carbon in their chemical structure.
The use of herbicides since about a century ago has been suggested as an effective way of eliminating crop competitors, though herbicides that remain in the soil for longer periods of time prolong weed control and thus increase weed management efficiency. On the other hand, their increased stability in soil may be of a magnitude that can damage crops in the following crop rotations. Soil properties can have a significant impact on the stability of herbicides in soil.
Materials and Methods For this purpose, soil samples were taken from 0-30 cm depth from field of experiment No. 2 in College of Agriculture Shahid Chamran University of Ahvaz. After sampling and passing through 2 mm sieve, the physical and chemical properties were measured using standard methods. The pot experiment was conducted in a factorial completely randomized design with 32 treatments including soil salinity (at 2.5 and 6 dS / m), Ultimo herbicide rate (at 4 concentration levels of 0, 25, 50 and 100% Recommended dose) and planting time (60 and 120 days after herbicide application) with 3 replication. Wheat was selected as the experimental crop and variety was "Mehregan" which has been cultivated in most of Khozestan province. Herbicide was applied and soil was rested for 60 and 120 days then wheat was sown. For germination percentage, wheat seeds were sown directly in soil after germination test. After germination the percentages were recorded and kept in an equal number of plants in the pot. It should be noted that in order to eliminate the effect of nutrient deficiency on plant growth at appropriate intervals, nutrient solution was applied and irrigated according to the need of the plant.After 9 weeks (before flowering stage) the plant was harvested and the growth components including root length, root dry weight, shoot length, shoot weight and nutrient concentration including nitrogen (in plant dry matter), phosphorus, potassium, calcium, magnesium, iron, zinc, copper and manganese were measured in the extract obtained from dry digestion of plant tissue (aerial parts of plant). Statistical analysis was performed using SAS software and mean comparisons were performed by Duncan's multiple range test. Charts were drawn using Excel software.
Results and Discussion According to the results, increasing the level of herbicide decreased the growth parameters of the plant, which is intensive under salinity stress. The results showed that considering 60 days sowing after herbicide application, shoot dry weight in 100% RD herbicide application in salinity of 2.5 dS/m was 1.6 g which was not showed significant difference with 50% herbicide application under salinity of 6 dS/m. Therefore, in higher salinity levels lower herbicide dose can damage the plant as much as higher levels of herbicides in lower salinity, and lower levels of herbicides in more soil salinity produce more negative effects. By increasing planting time from 60 to 120 days the residual effects of herbicides on soil decreased and plant showed better yield. By increasing salinity level from 2.5 to 6 dS / m, all growth components of wheat decreased, except for shoot length and shoot dry weight, this significant decrease was not reported for other components.
Conclusion Therefore, it can be concluded that selection of sowing time after herbicide application in crop rotations is very important and by selecting the correct time can greatly reduce the deleterious effects of consuming more herbicides.Planting wheat at 60 days after application of herbicide compared to 120 days after application of herbicide, decreased the growth components of the plant. Therefore, selection of wheat sowing time in crop rotation 60 days after application of herbicide (especially at 100% recommended dose) is not recommended in maize – wheat cropping system. Also considering soil chemical properties such as salinity as an influencing factor on herbicide behavior in soil can be effective in controlling residual effects of herbicides in soil and plant.

کلیدواژه‌ها [English]

  • Soil salinity
  • Herbicide residual effect
  • Growth parameters
  • wheat