Nicosulfuron postemergence is currently the most widely used treatment agent shoots, preparation for the 4% of the SC, the agent is the type of sulfonylurea herbicides in uptake and can be absorbed through the plant stems and leaves and roots and quickly in the xylem and phloem conduction, by inhibiting the activity of acetolactate synthase, branched chain amino acid synthesis obstacles, which affect plant cell division, so that weeds stop growing and eventually die. Potion weeds stop growing soon after, usually 4-5 days after application toxic symptoms appear, damage symptoms of heart leaf yellowing, chlorosis, leaf tip, leaf sheaths purple. Annual weed about 20 days of death, more than 6 leaves of perennial broadleaf weeds suppressed, stop growing, high doses can be deadly. 3-5 of the corn leaf, stem and leaf weed spray after a homogeneous base, 0.9-1.5 liters per hectare (equivalent to 36-60 grams of active ingredient / ha), can Control in Digitaria sanguinalis, Eleusine indica, Setaria, wild Millet, Amaranthus retroflexus, Chenopodium, sedge weeds.
Nicosulfuron to its unique advantage of becoming common postemergence corn herbicide leaf processing, due to inappropriate medication, some areas in recent years after the application of the drug produced a heavier injury. Nicosulfuron spray 5-10d after the symptoms of heart leaves of maize chlorotic, yellowing, or irregular chlorotic leaf spot; some leaves rolled into a cylinder-shaped, margin shrinkage, heart-shaped leaves are Shelter , does not work out; plant height, and sometimes will produce a profusion of secondary stems.
According to the analysis, corn nicosulfuron phytotoxicity there are several reasons. (1) the concentration of too much fertilizer dosage. (2) during the right medication. 2 leaf stage of corn before or after the 6 leaf stage is easy to use nicosulfuron phytotoxicity. (3) improper application methods. 5 leaves of maize is not directed spray after spraying, pesticides and even mix, a lot of liquid applied into the heart leaves of maize caused by injury. In addition, the corn used organophosphorus pesticide ethyl Takatoshi sense of tobacco, such as the interval of less than 7 days is easy to produce injury. (4), uneven spray, spray rate link with the overlap, leading to excessive local spray. Spray performance bad or non-standard field operations, such as multi-nozzle spray nozzle flow is inconsistent, leaking, etc., resulting in partial spray volume too much. (5) even after the drug case of cold rain vulnerable. (6) burst of sweet corn and maize, Takatoshi ethyl sense to smoke. The tolerance of the order of durum> General Type> General sweet> burst. (7) played without a net wash sprayer or soybean field sprayers Herbicide failed to timely and thorough cleaning and then spraying it nicosulfuron, easy to produce injury to the corn.
Nicosulfuron injury prevention, first of all, according to the soil, weather conditions, grass conditions to determine the dosage, uniform spray, do not re-jet, missed spray. Secondly, we must strictly adhere to medication timing. 3 to 5 leaf stage of corn on the most resistant to nicosulfuron, the safest medication at this time. 6 leaves of maize after the medication should be directed spray, avoiding contact with the liquid heart of corn leaves. 2 leaf stage of corn leaf before and after the appropriate treatment 10. Again, accurately calculate the dose, the amount of quasi-chemical control area to area of treatment, accurately dilute, uniform spraying, do not re-spray, spray does not leak, can not raise the number of pharmaceutical concentrations and spraying. Fourth, to improve the pesticide levels. Good spray performance, such as the Plant Protection Equipment Co., Ltd. Shandong defender produced WS-16P type manual sprayer and the Washington Agricultural Chemical Co., Ltd., Shandong Taishan-18AC-type production knapsack sprayer duster machines.
Corn nicosulfuron phytotoxicity by mild, temporary growth suppression, without treatment, can be restored after a period of time will not affect production. If severe injury may take the following measures: (1) pouring enough water to make a lot of corn roots absorb water, the body in order to reduce plant herbicide concentration. Adding water with ammonium bicarbonate, ammonium nitrate or urea fertilizer to promote root growth. Foliar spray can also be 1% to 2% urea solution or 0.2% to 0.3% of potassium dihydrogen phosphate or Huimanfeng 600 ~ 800 times. (2) spraying Bi protection, GA, Xie Ling harm, Yun -120 (natural brassinolide) diluted 1,500 times, gibberellin plus 1% urea solution or foliar treasure, can promote damaged plant resumed as soon as possible. (3) timely cultivator, enhanced soil aeration. (4) timely pest control, increase vigor. If these measures can not alleviate the symptoms of injury, damage to species or replant as soon as possible. (5) timely detoxification, in the smoke-ethyl injury has occurred or will occur, to take early measures to detoxification. On the initial injury on corn plants, water spray can be used 3-5 times a wash spray apparatus of pesticide residues on plants. (4) The injury occurred in the corn plots should be combined with water, increasing human and animal manure composting facilities, ammonium bicarbonate, ammonium nitrate, urea and other fertilizers available to promote root development and regeneration, restoring affected the physiology of corn, to reduce tobacco ethyl phytotoxicity on corn damage. While also foliar spray of 1% -2% urea or 0.2% -0.3% of potassium dihydrogen phosphate or Huimanfeng 600-800 times, enabling the growth of corn back to normal. At the same time, should actively Control in other corn pests and diseases, to improve the ability of corn against injury.
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