Using fungicides to effectively control corn leaf spot

Recently, the national corn industry technical system plant protection post expert Jin Qiming and Chen Jie team conducted a survey on the occurrence of pre-existing large spot disease in the counties and surrounding areas of Fuyu, Nong'an, Gongzhuling, Changling and Weinan in Jilin Province, and found that some The susceptible varieties have corn spot disease, and the upper leaves are also found to have lesions, most of which are grade 1-3, and the disease rate is 42-94%. In mid-June 2012, corn big spot disease has begun to occur, and the late stage of corn big spot disease outbreak is prevalent. According to the previous epidemic catastrophe law, if the rain is sufficient in July and August this year, the conditions are suitable, it will lead to large spots. The disease is once again outbreaking.

After the outbreak of the corn big spot disease in 2012, the yield loss survey was conducted for the high-sensitivity varieties in Jilin Province, and the losses caused by corn leaf spot (grades 7-9) in the central and western regions were over 20%. According to the average output of 9000kg/ha, the yield per hectare is lost by more than 1800kg. For example, the treatment of corn big spot disease agent Ami seconds (20% azoxystrobin + 12.5% ​​difenoconazole), 400ml per hectare, about 400 yuan, leased overhead spray about 200 yuan per hectare, per hectare About 600 yuan, in 2013, the pesticide control experiment has more than 80% control effect on the susceptible variety Xianyu 335, so the prevention and treatment can effectively recover the yield loss and the economic benefits are obvious.

With drug control:

1. Selection of medicaments

According to the local market for fungicides , it is preferred to have both systemic and protective fungicides. The main choices are difenoconazole, azoxystrobin, pyraclostrobin, and syringic acid ester. Or a fungicide of the above ingredients. Such as: Ami wonderful harvest (20% azoxystrobin +12.5% ​​difenoconazole. 1000-1500 times liquid); clove • tebuconazole + azoxystrobin (10% syringic acid + 30% tebuconazole + 25% azoxystrobin, 1000-1500 times solution), pyraclostrobin (250 g/L, 50 ml/mu), and the like. Mix with water according to the instructions.

2, spraying equipment

Conditional optional advanced equipment such as overhead stalk sprayer and aircraft can be used. If the conditions are insufficient, a manual knapsack sprayer can be used. Apply in the windless weather in the evening.

3, spraying time

Before and after the big bell period, the overhead stalk sprayer (which is not convenient for mechanical walking) can be used for foliar spray. The first spray should be applied sooner or later, sprayed once every 7 days, and continuously sprayed 2- 3 times best.

4, matters needing attention

Due to the toxicity of the sprayed drug, it is necessary to pay attention to self-protection, bring a mask, and wear protective clothing.

Pesticides want to get more knowledge, please pay close attention to China Pesticide Network