In the early stage of corn production, that is, in the seedling stage, there are many pests and diseases in the field, which affect the normal growth of corn plants, resulting in reduced yield in the late stage of corn. Correct identification of the hazard symptoms and hazard characteristics of common pests and diseases in corn seedlings, and timely and reasonable control measures can reduce the damage caused by pests and diseases to corn and increase corn yield. 1 rot 1.1 symptoms After the corn seedlings are susceptible, the roots become brown, rot, hypocotyl contracture, dryness, root hair reduction, secondary roots are absent or rare, affecting the normal growth of corn, resulting in reduced corn production. 1.2 Prevention and treatment technology 1.2.1 Agricultural control Before sowing, it can be coated with a suspension of chlorhexidine suspension seed coating, which has better control effect on root rot. Strengthen the field cultivation management, spray foliar fertilizer; the plot with high humidity, carry out cultivating and dehumidification, and promote the growth and development of root system. 1.2.2 Chemical control In the case of severely affected plots, 72% mancozeb, cumin, cyanide, WP, 600 times, 58%, mancozeb, and metalaxyl WP can be sprayed on the base of the corn seedlings or roots. 2 top rot 2.1 symptoms After the leaves are susceptible, the middle and upper leaves are chlorotic, deformed, shrunken or distorted; the marginal tissue is yellowed and stripped, or the blade tip is dead. 2.2 Prevention and treatment technology In the early stage of the disease, 50% carbendazim WP, 80% mancozeb WP, 5% bactericidal water, 72% agricultural streptomycin soluble powder can be used. 3 rough disease 3.1 symptoms The disease is a viral disease caused by the poisoning of the gray planthopper, the susceptible plants, the leaves are thick green, the internodes are shortened, the leaves are stiff, wide and thick, and the clusters are like a cranberry. The heart leaves are small, the veins are intermittently veined, and waxy white veins are produced on the leaf veins on the back of the leaves. 3.2 Prevention and treatment technology Plant disease-resistant or disease-tolerant varieties, and use seed extracting agents such as thiamethoxam and imidacloprid for seed coating to reduce the damage of Laodelphax striatellus. When the seedlings are planted, the diseased seedlings are removed and taken out of the field for deep burial. Adding organic fertilizer and phosphorus and potassium fertilizer can improve the disease resistance of corn plants and reduce the incidence. 4 dwarf mosaic disease 4.1 symptoms In the seedling stage, the veins form chlorotic stripes with different lengths and different shades. The inter-pulmonary mesophyll is chlorotic and yellow, forming obvious streaking symptoms. 4.2 Prevention and treatment technology The disease is a viral disease caused by the transmission of aphids. When the disease is prevented, comprehensive prevention and treatment measures for treating diseases and preventing diseases should be taken. Use resistant varieties. Suitable for late broadcast, to avoid or reduce aphid transmission. It can be mixed with imidacloprid or special seed coating agent to control aphids and reduce the number of drug delivery mediators. Timely removal of field disease vaccines and reduction of drug transmission opportunities. 5 Little Land Tiger 5.1 damage characteristics The small ground tiger is a typical omnivorous pest. It is harmed by larvae. It is lurking in the soil during the day. It is unearthed at night, and the base of the stem of the corn seedling is bitten off, causing the corn to lack seedlings and ridges, and even destroying the re-broadcast. 5.2 Prevention and control technology Use insecticidal lamps to trap adults. Saute the bait and other bait, use 4 to 5 kg of bait per 667 m2, add 90% of 30% trichlorfon crystal 30 times, mix well into a poison bait, and sprinkle it on the cornfield ground in the evening to trap the small tiger. In the 1st to 3rd instar larval stage, 48% chlorpyrifos EC 90-120 g or 50% phoxim EC 800 times solution, 2.5% deltamethrin EC 3 000 times solution, 20% fenvalerate can be used per 667 m2. The emulsifiable concentrate is sprayed with 3,000 times of liquid, and the focus is on spraying the soil around the corn seedlings. 6 Golden worm 6.1 Harmful features The golden worm is a larva of the mites, which is a polyphagous underground pest. The main species are sphaerocephala, fine-skinned golden worm and brown-spotted golden worm. The golden worms bite seeds, seedlings, and young roots with larvae. 6.2 Prevention and control technology 40% chlorpyrifos EC 1500 times solution, 40% phoxim emulsifiable concentrate 500 times solution and appropriate amount of fried wheat bran or bean cake mixed to make poison bait, sprinkle into the corn base in the evening ridge; or mix insecticide in seeds and fertilizer Agent control. 7 square 7.1 harm characteristics Adults and nymphs are active in the soil, feeding on seeds, young shoots, or The seedlings were bitten and killed, and the roots of the corn were damaged. Nocturnal night, 9-11 in the evening for the peak of activity feeding. 7.2 Prevention and treatment technology Seed dressing with 50% phoxim emulsifiable concentrate at a seed weight of 0.3%, or mix with bait. When planting, spread it in the seeding ditch. It can also be made with 40% dimethoate emulsified with a moderate amount of fried wheat bran or bean cake, and sprinkled in the corn field in the evening. The first-instar nymph is the best time to control oriental cockroaches. It can be used with 40% acephate emulsifiable concentrate 1000 times solution, 10% imidacloprid WP 2000 times solution, 48% chlorpyrifos emulsifiable concentrate 1500-2000 times liquid sprayed corn seedling base. Or rooting. 8 Hummer 8.1 harm characteristics Adults and nymphs clustered on the front and back of the leaves to suck the mesophyll and juice, leaving only the epidermis at the site, forming white spots and a large amount of dark brown feces. For the heavily damaged field, the leaves are white, the leaves are dull, brittle and hard, but not deformed, not falling off, until dry. Plant growth is slow, flowers are small, flowering is delayed or not flowering. 8.2 Prevention and treatment technology In the early stage of the thrips, 10% imidacloprid wettable powder 1500 times solution, 1.8% avermectin EC 2 000-3 000 times liquid spray leaves and heart leaves can be used. 9 sticky insects 9.1 harm characteristics Zygomycosis can harm wheat, corn, sorghum, rice and other food crops and pastures. It is an omnivorous, migratory and intermittent outbreak of pests. When the worms outbreak, the corn leaves can be eaten, which affects the normal growth of the corn. 9.2 Prevention and treatment technology It can be trapped into insects with sweet and sour liquid, black light or corn grass. Before the 3rd instar larvae, 5% flubendialdehyde emulsifiable concentrate 4000 times solution, 20% chlorfenapyr 1 2,000 times solution, 25% chlorfenapyr 3 500-1000 times solution, 20% methrin emulsifiable concentrate 2000 Double solution, 50% phoxim emulsifiable concentrate 1000 times solution, 25% cyanopentyl phoxim emulsifiable concentrate 1500 times solution, 10% avicosin emulsifiable concentrate 1000 times solution spray control. The above is the prevention and control technology of the main pests and diseases of corn seedlings. Welcome the majority of growers to come to Huinong.com to learn more! Anesthesia Medical Co., Ltd. , https://www.honestymed.com
