How to Control Diseases and insect pests of Summer Maize

How to control summer corn diseases and insect pests? Please introduce that there are many kinds of diseases, insect pests and weeds in summer sowing period and seedling stage, and the harm is serious. If the prevention and control is unfavorable, it is very easy to cause lack of seedlings and broken ridges, resulting in yield reduction. Therefore, in the whole growing period of maize, it is very important to do a good job in the integrated control of diseases, insect pests and weeds at sowing and seedling stage. First, occurrence characteristics 1. The seedling stage is the key to the control of disease and Cordyceps in the whole growth period. The underground pests of ① showed an upward trend. The main underground pests in corn field are ground tiger, grub and golden needle worm, which are the main reasons for the lack of seedlings and broken ridges in maize seedling stage. The pests in seedling stage of ② are seriously damaged. Maize seedling stage is the stage of concentrated damage of thrips, Swedish flies, armyworm, cotton bollworm, sunflower pink scale and other pests, often resulting in lack of seedlings and broken ridges, heart leaves curling, growth retardation, serious plots and even seed destruction. Therefore, it is the key to do well the pest control in maize seedling stage. In recent years, the damage of corn thrips and Swedish flies showed an aggravating trend, and the damage was often mixed, and the plots sown early and covered with wheat straw occurred more seriously. the main damage time was in the 3-7 leaf stage, and the latent damage was in the 1-leaf stage (that is, 1-2 days after maize emergence). During this period, the heart leaf curl was formed at the 3-7 leaf stage, and the second damage was formed in some plots from late July to early August. The mixture of the second generation armyworm and the second generation cotton bollworm often caused seed destruction in some fields. The tillage sunflower pink scale postponed the jointing stage of corn and grew slowly. The weeding effect of some corn fields in ③ is not ideal, the main reason is that wheat straw mulching is not conducive to the use of pesticide before sowing, the second is insufficient water consumption, and the third is that the spraying time after seedling is not mastered. two。 New diseases and insects continue to appear. The local occurrence of ① heterofirefly was severe. The middle and lower leaves of corn were seriously damaged. Spodoptera litura ② is harmful to the root and stem of maize at seedling stage. 3. The old diseases and insects are on the rise. ① maize root rot and smut occurred seriously in some plots. Some susceptible varieties of ② maize sheath blight were more serious. ③ maize rough dwarf disease caused serious dwarfing, stunting, no heading and less fruiting. Seed treatment and chemical weeding 1. Select disease-resistant and high-yield varieties and do a good job in seed treatment. Xianyu 335, Jingdan 28, Zhengdan 958 and Liyu 16 have grown well in recent years, and farmers can choose to plant them. two。 Seed treatment: ① can control underground pests with 40% methyl isosphos 100ml plus 2.5kg of water, 50kg of mixed corn seeds, piling up for 4-6 hours, drying and sowing, which can effectively control underground pests and gray planthoppers. ② can use 50% carbendazim wettable powder or 25% trimethoprim wettable powder to control root rot, and mix seeds according to 0.5% of seed weight. ③ can be used to control smut and head smut with 50% wilting Ling, 50kg seed medicine 250g or 6% Likexiu suspension seed coating agent, the dosage of each kilogram seed is 1ml. 3. Science, chemistry, weeding. It is recommended to use 40% Yi A mixture before sowing, 200ml per mu, 45 kg of water, and inverted spray on the ground; Gengjie and 23% smoke density are recommended for post-seedling corn at 2-4 leaf stage. Atrazine, etc., 100ml / mu, 30kg water spray between stems and leaves (avoid corn heart leaves). More than 10 leaves of corn can be sprayed with gram-free directional spray. Quality requirements: ① dosage, sufficient water; ② spray time after 5: 00 p.m.; ③ spray uniform, no re-spray, no leakage spray. When ④ was sprayed with nicosulfuron-methyl herbicide, organophosphorus pesticides could not be used before and after 7 days. Third, pest control measures (1) Swedish flies and thrips: pay attention to early sowing and stubble sowing. If the rate of damaged plants after seedling is 2% to 3%, chemical control will be carried out immediately. The spray should be uniform and the amount of medicine and water should be sufficient. Use medicament: 2.5% cypermethrin 30ml plus 50% dimethoate 30ml or mu 10% imidacloprid 20g 30g plus 2.5% cypermethrin 30ml, 30kg / mu, spray the whole field. (2) Corn sunflower scale: the root was irrigated in time with 1000 times of 40% phoxim EC or 48% Lesben EC at seedling stage, 150 kg per mu. The method is to remove the sprinkler cover and spray the base of the corn stem to make the liquid seep into the corn rhizome. (3) Helicoverpa armigera and armyworm: timely drug control when the plant rate is more than 5% in the first ten days of July. Use 4.5% cypermethrin and 40% phoxim 1 ∶ 1 to mix 50 mu 75 ml or 25% Huifeng fast gram mu 50 ml spray. (4) Corn borer: the corn borer was perfused with granules at the end of corn heart and leaf (big trumpet stage). The granules were made with corn borer special granules or 40% phoxim EC 0.5 kg mixed with 5 kg water and 5 kg furnace ash. 3.5 kg per mu was applied to the corn heart. Control standard: corn flower and leaf rate is up to 20%. (5) Maize rough dwarf disease: small fields, early sowing fields, complex environment, wheat cluster dwarf occurrence of corn should be carried out in time to create an environment not conducive to planthopper reproduction and prevent the occurrence of maize rough dwarf disease. Main measures: large-scale removal of weeds in the field and edge of the field before sowing or emergence of ① corn, reducing poison sources and advocating chemical weeding. ② should fertilize and irrigate rationally, strengthen field management, shorten the time of maize seedling stage, reduce the chance of virus transmission and improve the disease resistance of maize. ③ corn before and after sowing and seedling stage sprayed 50% acephate EC 1500 times on corn field and surrounding weeds. (6) Spodoptera litura: 48% chlorpyrifos 1 jin + 100 jin cotton kernel powder was used as poison bait in the evening, and the control effect was more than 90%. 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