Key Technical Points for Pest and Disease Control During the Cotton Seedling Stage
Due to the influence of ecological conditions, meteorological factors and so on, pests and diseases during the cotton seedling stage are characterized by many species, rapid development and severe damage, often causing missing seedlings and broken rows in cotton fields, and in severe cases, large areas of death. The main diseases that occur include black root rot, red rot, damping-off, anthracnose, cotton aphids, cutworms and so on. For control, pesticides should be applied scientifically at the appropriate time for integrated management.
1. Agricultural measures: For cotton cultivation, high-quality, high-yield, disease-tolerant varieties should be selected and sown at the appropriate time; secondly, management should be strengthened, base fertilizer increased, seedlings thinned early and timely final thinning carried out, irrigation strengthened during the dry season, and deep intertillage carried out after rain to raise soil temperature, reduce soil moisture and enhance soil aeration; thirdly, weeds in and around cotton fields should be cleaned up to reduce the number of pest and disease sources.
2. Early prevention of seedling diseases: At the initial stage of disease in cotton seedlings, 50% carbendazim wettable powder at 600 times or 70% thiophanate-methyl wettable powder at 800 times can be sprayed for control; for fields with more severe disease, 40% carbendazim suspension concentrate or 65% mancozeb wettable powder can be sprayed once every other week, for 2 consecutive sprays.
3. Scientific aphid control: After the summer harvest, large numbers of natural enemies migrate from wheat fields to cotton fields. At this time, the use of chemical pesticides can be reduced to give full play to the control effect of natural enemies on aphids. When aphids occur severely, 10% imidacloprid wettable powder at 1500 times solution or 50% pirimicarb wettable powder at 1000 times solution can be sprayed for control, and attention should be paid to alternating pesticides to slow the development of resistance.
4. Control of cutworms: When cutworms are causing damage in cotton fields, 50 grams of 50% phoxim can be mixed with 1 kg of water and sprayed and mixed onto 5 kg of roasted wheat bran or crushed cottonseed cake to make poison bait, then scattered along the rows in the evening to trap and kill the larvae; or 20% fenvalerate at 1500 times solution, or 50% phoxim at 1500 times solution, or 800 times kung fu plus 800 times decis can be sprayed for control.