اثرکاربرد سوپرجاذب و محلول‌پاشی آهن و روی بر فعالیت آنزیم‌های آنتی‌اکسیدان و عملکرد ذرت دانه ای (s.c.704) (.zea mays l)تحت رژیم های آبیاری

به‌منظور بررسی اثر محلول‌پاشی آهن، روی و کاربرد سوپرجاذب در شرایط تنش کم آبی بر عملکرد دانه و فعالیت آنزیم‌های آنتی‌اکسیدان ذرت، آزمایشی به صورت کرت‌های دو بار خرد شده در قالب طرح بلوک‌های کامل تصادفی با سه تکرار طی سال‌های زراعی 96-1395 و 97-1396 در مزرعه‌ای واقع در شهرستان شوشتر اجرا شد. عامل اصلی شامل رژیم‌های آبیاری با سه سطح (آبیاری پس از تخلیه 30، 40 و 50 درصد ظرفیت زراعی به ترتیب آبیاری مطلوب، تنش ملایم و تنش شدید) که زمان اعمال تنش حدود 60 روز بود، عامل فرعی شامل پلیمرسوپرجاذب با دو سطح (شاهد (عدم مصرف سوپرجاذب) و 200 کیلوگرم در هکتار) و عامل فرعی فرعی شامل محلول‌پاشی عناصرریزمغذی با چهار سطح (شاهد (آب معمولی)، محلول‌پاشی آهن، محلول‌پاشی روی و محلول‌پاشی آهن و روی) بود. نتایج تجزیه واریانس مرکب نشان داد تاثیر رژیم آبیاری و سوپرجاذب بر عملکرد دانه، وزن هزار دانه، تعداد دانه در بلال، آنزیم کاتالاز و سوپراکسیددیسموتاز معنی‌دار بود. در شرایط تنش کم آبی عملکرد دانه، تعداد دانه در بلال و آسکوربات پراکسیداز کاهش یافت اما فعالیت آنزیم‌های کاتالاز و سوپراکسیددیسموتاز افزایش یافت. از طرفی برهمکنش رژیم آبیاری و سوپرجاذب بر عملکرد دانه معنی‌دار شد. بیشترین عملکرد دانه (8530.69 کیلوگرم در هکتار) مربوط به تیمار آبیاری پس از تخلیه 40 درصد ظرفیت زراعی و کاربرد 200 کیلوگرم در هکتار سوپرجاذب بود. همچنین برهمکنش رژیم آبیاری و محلول‌پاشی آهن و روی بر عملکرد دانه، سوپراکسیددیسموتاز معنی‌دار بود. محلول‌پاشی آهن و روی در شرایط تنش رطوبتی موجب افزایش عملکرد دانه، تعداد دانه در بلال و سوپراکسیددیسموتاز شد. به‌طور کلی با توجه به پایداری چندین ساله سوپرجاذب در خاک می‌توان بیان نمود که کاربرد 200 کیلوگرم در هکتار سوپرجاذب و محلول‌پاشی آهن و روی در شرایط رطوبتی تنش ملایم می‌تواند موجب افزایش عملکرد دانه، اجزای عملکرد ذرت و در کل بهبود 45 درصدی تولید ذرت شود.

The effect of superabsorbent and iron and zinc foliar application on antioxidant enzyme activity and yield maize (S.C.704) (Zea mays L.) under irrigation regimes

Introduction Maize (Zea mays L.) is one of the most important cereal grains that is cultivated in more than 180 million hectares, and its production is over 1000 million tons. The occurrence of water stress causes metabolic disorders in plant cells, such as the increase in the production of active forms of oxygen such as radical superoxide, hydrogen peroxide and radical hydroxyl as one of the major factors in metabolic abnormalities in the cell. Plants against oxidative stress induced, efficient defense system that can destroy or neutralize free radicals. This defense system includes superoxide dismutase, catalase and ascorbate peroxidase. Correct management practices and the application of advanced techniques to maintain moisture storage and increase water holding capacity are effective measures to increase the efficiency of irrigation and thus improve the utilization of water resources. One of the new methods for increasing irrigation efficiency is the use of superabsorbents. Superabsorbent polymers can absorb large amounts of water or aqueous solutions and swell. These water storage tanks, when placed in the soil, absorb irrigation water and rainfall and prevent it from quenching. After the environment is dry, the water inside the polymer is gradually evacuated, and thus the soil for a period of Long and no need to reirrigate, it’s moisturizing, it also increases the impact of plant and nutrients, and, on average, reduces phosphorus losses by 84 percent, reducing nitrogen to 83 percent. Therefore, the purpose of this study was to investigate the effect of iron, zinc, and superabsorbent application of water deficit stress on quantitative yield and corn antioxidant enzymes activity in Shushtar climate.   Materials and methods This research was carried out in two years between 20162017 and 20172018 in a farm located in Shushtar with a longitude 48 degrees and 49 minutes east and a latitude 32 degrees and 14 minutes north and a height of 110 meters from the sea level. The experiment was carried out as split split plot in a randomized complete block design with three replications. The main factor was irrigation regime with three levels (irrigation after 30, 40 and 50% field capacity depletion, respectively). Subfactor was composed of twolevels of polyurethane foam (superadsorbent, 0 and 200 kg ha1) and subsubplots including spraying of nutrients with four levels [control (water), iron spraying, zinc spraying and spraying Iron + zinc].   Results Combined analysis of variance showed that the effect of water deficit and superabsorbent stress on grain yield, 1000 grain weight, number of grain per ear, catalase enzyme and supraoxydisodium were significant. In dehydration conditions, grain yield, number of seeds per ear and ascorbate peroxidase decreased, but the activity of catalase and superoxide dismutase enzymes increased. On the other hand interaction of dehydration and superabsorbent stress was significant on grain yield. The highest grain yield (8530.6 kg ha1) was attributed to irrigation after 40% capacity utilization and application of 200 kg/ha superabsorbent. Spray application of iron and zinc resulted in increased grain yield, number of seeds per ear, catalase and superoxide dismutase.   Conclusion Overall, the results showed that foliar application of micronutrients and superabsorbent important role in the growth and development of corn plants as well as the fact that the highest values of grain yield and activities of antioxidant enzymes of fertilizer zinc and iron from micronutrients are, It can be concluded that using such fertilizers can provide the best conditions for obtaining maximum yield and biochemical traits in corn. On the other hand, iron and zinc micronutrient spraying caused a decrease of 45% damage caused by water deficit stress on grain yield. The superabsorbent effect is also more pronounced in lower moisture content. The application of superabsorbent hydrogels in the soil increased plant yield and saved water consumption, therefore the use of this substance in less water can be effective in increasing the yield and reducing the adverse effects of stress in conditions of water shortage. Therefore, according to the results obtained in irrigation conditions after discharge of 40% of the crop capacity, the application of polyester absorbent and micronutrient application of iron and zinc improved seed yield and biochemical traits of corn.