Wheat cultivation is subject to many adverse factors, but many experts may focus on weeding, fertilization and, importantly, scab. In fact, there is a disease in the wheat field, as long as you miss the control period and choose the wrong control formula, the later wheat lodging and white ear yield reduction cannot be ignored!
1. What are the symptoms of wheat sheath blight?
Wheat sheath blight can occur in the whole growth period of wheat, wheat sheath blight generally begins to infect from the base of the wheat stalk, as the stem spreads to the leaves, the most significant symptom of sheath blight, the epidermis of the base of the stem is yellow-brown in the early stage, the epidermis of the stem in the middle stage is infected and penetrated through the brown spots on the stem, and the whole stem base has water-stained whorle-like spots in the later stage, similar to boiling water or patches like children's diapers! If the control is not timely, it will spread to the leaf sheath and leaf mold layer of wheat!
2. Why does sheath blight occur in wheat?
1. Straw returning to the field; With the full amount of straw returned to the field, the field fungus source was sufficient, and the straw provided a favorable hiding place for the fungus source. Wheat sheath blight is a soil-borne disease, the pathogen can overwinter on the soil and straw, as long as the temperature reaches 15 degrees, it will explode damage, the straw is not solved, and the disease is aggravated year by year!
2. The density is too large; Excessive sowing of wheat has become a common problem, and excessive sowing amount leads to too large groups, canopy in the field, and seedlings are crowded with seedlings, and normal ventilation and ventilation cannot be aggravated, which will aggravate the occurrence of sheath blight! This is a fatal problem for wheat in the northern arid and dry rotation areas!
3. Poor drainage: for rice stubble and wheat harvest, it depends on whether the three ditches are unblocked, whether the water in the field can be discharged, when the water in the field is too much, the air in the soil is reduced, and the wheat will enter anaerobic respiration, at this time, the resistance of wheat will decline, and the roots will begin to appear lesions. At the same time, the humidity is high and the source is sufficient, and wheat sheath blight occurs seriously! This is a problem that cannot be ignored in rice and wheat fields!
4. Partial nitrogen fertilizer: 50 60 kg of nitrogen fertilizer needs to be applied to the whole growth cycle of wheat. If too much nitrogen fertilizer is used, wheat will have poor resistance, poor stalk toughness, thin cell wall, easy to get sick and lodging, which will aggravate the occurrence of sheath blight!
5. Prevention and control is not right: the prevention and control of wheat sheath blight can not be done blindly in accordance with the theory of plant protection, but also combined with the current climate and field conditions to prevent and control, many farmers will prevent and control wheat sheath blight after jointing, in fact, this time sheath blight has occurred, this period can only be sheath blight, once the sheath blight will affect the growth of wheat!
3. Wheat sheath blight prevention and control program?
Prevention and control period: the prevention and control of wheat sheath blight is not after jointing, it must be in the early stage of regreening to jointing, at this time, the application of pesticides can prevent the occurrence of sheath blight, and can also inhibit the reduction of other overwintering pathogens in the field, which can reduce the occurrence of diseases in the later stage.
Prevention and control methods: the prevention and control of wheat sheath blight is to draw more water, the second is to add additives, and the third is to mix with herbicides, but can not use azoles and methoxyacrylate fungicides.
Prevention and control agents: use alone prevention and control formula: fluconazole, oxime strobin. Tebuconazole, tebuconazole. pyraclostrobin; Mix with herbicides: thiofuramide.