Prevention and control methods: early in the disease, spraying 20% bacteriophage soluble powder 1000 times; 75% Chlorothalonil wettable powder 800 times or 72% Manganese zinc - Frost Urea 800 times with a wide range of special effects king.
(2) corn coarse shrinkage disease. Corn coarse shrinkage disease is mainly transmitted by gray fly. After the onset of the plant is severely dwarfed, generally only 1/2 or 1/3 of the height of the healthy plant. leaf blade dark green, wide short hard, was opposite; leaf back side veins often appear on the wax white protrusions, with the hand touching the obvious roughness. Corn 5-leaf period easily infected.
Prevention methods: ① before and after sowing with 18% of the vast A peck net 1500 times solution of the corn field and the surrounding weed spray, kill gray fly; ② seedling can be used in the 15% virus Bik 600 times spray.
(3) green blight. Corn green blight mainly occurs at the end of filling, is a violent, destructive disease, easy to cause serious yield losses.
Symptom identification: corn at the end of the irrigation often manifested as a sudden green blight wilting, the whole plant leaves were scalded dry and faded; cob drooping, bracts dead; stem base at first water-soaked, and then gradually become light brown, hand pinch has a hollow feeling, often leading to collapse.
Factors affecting the onset of the disease: the cause of green blight is still debated, there are mainly three different views: one, it is caused by Fusarium; second, it is caused by Pythium; third, it is caused by a composite infestation of Pythium and Fusarium. However, heavy rainfall during the period from filling to milk ripening has an important effect on the development of the disease, and the high water content in the soil is an important condition for the development of cycad.
Prevention methods: there is no effective control measures, but the difference in resistance between varieties is extremely significant, you can choose resistant varieties. Production of commonly used disease-resistant varieties are: Yu Yu 4, Liao single 18, Shaanxi single 9. Cultivation measures should promote full seedling, pay attention to drainage.
(4) corn silk black tassel disease. This disease mainly harms the corn cob and male flowers, once the disease, usually the whole plant grain. Therefore, the incidence of the disease is equal to the loss rate of the disease, the harm is quite serious.
Symptom recognition: This disease is a systemic disease that invades from the maize bud sheath during the seedling stage, and the symptoms are mainly manifested after the male pumping. Diseased cob appearance is shorter than normal cob, the base is large and pointed at the end, the top of no filament extraction. Sometimes one side of the bracts split, revealing black powder, the sick cob all turned into a black-brown spore pile, the spores are not easy to disperse, which is mixed with the residue of the vascular bundles of the corn plant.
Factors affecting the onset of the disease: the pathogen to fall into the soil, mixed with manure or seed carried by a kind of resistance to the adverse environment of the special spores - thick wall spores overwintering, the following year in the appropriate conditions, thick wall spores sprout and invade the host seedlings through the bud sheath. After the invasion, the mycelium enters the growing point of the plant, grows with the plant, spreads to the fruiting spike and male flowers, forms a spore mound, and then disperses spores after maturity, completing the cycle of infestation once a year, without reinfestation.
The amount of bacteria in the soil and manure, as well as the temperature and humidity conditions of the soil are the most important factors affecting the occurrence of this disease.
Prevention methods: ① Selection of disease-resistant varieties. There are obvious differences in resistance to the disease between varieties. At present, the production of commonly used disease-resistant varieties are Zhongdan 2, Zhongdan 14, Zhongdan 12, Liao single 18, Dan Yu 13, Shaanxi single 9, Yu Yu 2, Yu Yu 11 and so on. ② Crop rotation, deep plowing. Continuous cropping for many years is easy to make the soil bacteria increase, the disease is heavy. The implementation of more than 3 years of crop rotation, basically eliminating the damage of soil pathogenic bacteria. In addition, deep turning of the soil, the spores of the disease will be overwhelmed below the seeding layer, in order to reduce the source of bacteria, reduce the onset of disease. ③ Early pulling out of diseased plants. Pull out the diseased plant before the white membrane of the diseased spike is not broken, and take out the diseased plant out of the ground and bury it y or burn it, so as to avoid the pathogens falling into the soil.
(5) Asian corn borer. The corn borer, also known as the driller, belongs to the Lepidoptera. Mainly harm the corn heart and leaves and ears, stalks.
Methods of control: ① Seedling per mu available 3% furadan 1 ~ 2 kg added 1 times the fine soil or fine sand, evenly sprinkled into the heart leaves. ② before pumping male with high efficiency biological insecticide Su Wei Shi or 18% of the vast A pecking net 1500 times plus the vast special effect king spray.
(6) sticky insects. Also known as night robbers, five-colored bugs and so on. Lepidoptera, mainly harmful to corn leaves. If not prevented at a low age, the larvae entering the 6th age stage can eat the whole corn seedling and leaves in 3 to 5 days, causing serious losses. The insect comes out day and night, starts its activities in the evening, and feeds at dusk. It is pseudo-dead and afraid of light.
Prevention methods: field 100 corn pests up to about 30 head, should be immediately for control, per mu available 50% phoxim 1500 times night spray; the older age available 0.1% Suwis or 18% A peck net 1500 times liquid plus with the vast number of special effects king spray.
(7) corn aphid. The aphid is also known as the putty bug. Homoptera, Aphididae. To prick suck leaf juice harm, secretion of honeydew and produce mold, seriously affect the photosynthesis of the leaf. At the same time, the corn aphid can also spread corn virus disease.
Prevention methods: corn trumpet period, with 10% Boom aphid 1000 times liquid spray or 10% imidacloprid wettable powder 2000 times liquid spray, or 8% of the big Gongshen 1500 times plus a wide range of special effects of the king spray.
Corn tons of Tianbao is not an insecticide and fungicide, but foliar spraying corn tons of Tianbao can enhance the resistance of corn to pests and diseases. Foliar spraying corn tons of Tianbao can resist large spot disease, small spot disease, green blight, and can reduce the damage of corn borers, aphids and stick insects.