Control cotton diseases, insect pests and weeds at sowing date and seedling stage

This year, due to the influence of abnormal climate, the sowing time of cotton in our province was postponed. Under the condition of continuous low temperature, the growth and development of cotton was delayed, and the harm degree of diseases and insect pests was relatively aggravated. To this end, cotton is facing a more severe situation of pest control this year. From the beginning of sowing, we should firmly implement the key of each prevention and control technology, especially the technical link of drug selection. Now the main pest control techniques in sowing and seedling stage are introduced to the broad masses of farmers as follows:

First, strict chemical treatment of seeds in sowing period before sowing cotton seeds should focus on seed dressing measures to effectively control cotton seedling diseases, seedling aphids and underground pests. First, choose the seeds coated with insecticides and fungicides; second, put an end to the white seeds, soaking and dressing seeds: ① seeds de-velvet with sulfuric acid. Soaking seeds with ② can effectively control cotton blight, anthracnose, red rot, brown spot, black spot, verticillium wilt and other diseases, seedling aphids and underground pests. To control the disease, more than 40% carbendazim glue suspension can be used to soak seeds with 0.3% active ingredient at room temperature for 14 hours, remove and dry them for sowing, or soak cotton seeds with 2.5% chlorpromazil suspension 300ml, add 1kg water and 100kg cotton seeds, or soak the seeds in warm soup, that is, soak the seeds in 55-60 ℃ warm water for 30 minutes, stir every 5 minutes, remove and mix the seeds. To control seedling aphids, 0.5 kg of Owl head water dispersible granules (70% imidacloprid), 1.5 kg of water, 100 kg of mixed cotton seeds, or 0.3 kg of 40% methyl isophosphates EC 0.3 kg of water and 2 kg of mixed cotton seeds can be fully absorbed and dried, while controlling underground pests.

2. Seven days before sowing, 75 ml of 40% trifluralin EC was sprayed on the soil surface with 40% trifluralin per mu. Immediately after spraying 30 kg of water on the soil surface, the soil should be mixed evenly, or 33% pendimethalin 120 ml 150 ml to 30 kg of water should be evenly sprayed on the soil surface before sowing, which can effectively control annual Gramineae weeds and some broad-leaved weeds.

Third, do a good job in the prevention and control of diseases and insect pests at seedling stage

1. Disease control. In the initial period of blight, anthracnose, sudden fall and red rot, 50% carbendazim wettable powder 500 × 800 or 75% thiophanate methyl wettable powder 800 × 1000 times spray, once every 7 days, according to the disease generally spray 2 times 3 times.

two。 Pest control. ① aphid control. When the leaf curling rate in front of 4 true leaves of cotton seedlings reaches 3%, the owl head water dispersible granule (70% imidacloprid) can be used to control it. Or 2000 times of imidacloprid wettable powder or 4000 times of spray of three-hit (5% acetamiprid) microemulsion or 5% acetamiprid (5% acetamiprid) wettable powder. At the same time, it can be reasonably mixed with 1000 times liquid of organophosphorus pesticides such as omethoate and chlorpyrifos. Control agents should be used alternately. ② cotton red spider control. Red spiders are mostly concentrated on the back of cotton leaves, pricking and sucking juice, causing mechanical damage to cotton plant tissue and secreting harmful substances to poison leaf tissue at the same time. After the damage to cotton leaves, there are yellow and white spots that lose green first, followed by local erythema, which are enlarged and scorched, like burning. The prevention and control should be "early". During the occurrence period, you can choose 5 points (5% avermectin) 4500 times liquid, or hit Yat (3% avermectin) 4000 times liquid, easy to play (2% avermectin) 3000 times liquid spray control, can be mixed with omethoate EC or dactylol and other 1000 times solution to improve efficacy and reduce cost. ③ cotton blind stink bug control. The main cotton blind bugs in our province are green bug, alfalfa bug, three-point bug and medium-black bug, which suck the sap of cotton plants with adult and nymph thorns, resulting in bud and boll shedding, broken leaves and broken branches. The cotton fields with exuberant cotton growth and more buds occurred more seriously. With the popularization of insect-resistant cotton and the decrease of the number of pesticides used in cotton field in recent years, the occurrence of cotton blind stink bug is becoming more and more serious. it has become a major pest in cotton field and occurs for 5 generations a year in our province. Before wheat harvest, the seedling stage of cotton in our province is the harm period of the first generation of blind Toona sinensis, and the bud is the harm period of the second generation of blind Toona sinensis. These two periods are the key links of prevention and control. The first-generation control should be sprayed when there are about 3 nymphs in 100 cotton seedlings, and the second-generation control should be sprayed on about 10 nymphs in 100 cotton plants. the owl head water dispersible granule (70% imidacloprid) can be used 2000 times, or 2000 times of imidacloprid wettable powder or 4000 times of dimethoate or chlorpyrifos should be mixed with dimethoate or chlorpyrifos. It can also be sprayed with 1000 times of 4.5% cypermethrin EC, or 1000 times of hunting (20% malathion-fenvalerate) EC. A variety of agents should be used alternately to improve the duration and control effect.