How to treat corn small spot disease?

How to treat corn leaf spot? Please guide the prevention and control of maize leaf spot disease can refer to the following methods: first, the symptoms of maize leaf spot disease can occur in the whole growing period of maize, mainly damage leaves, leaf sheaths, bracts and ears can also be damaged. The disease occurs first from the lower leaves of the plant, and spreads upward and expands. Due to the different resistance of varieties, there are three types of leaf disease spots: (1) irregular oval disease spots, or nearly rectangular due to the limitation of leaf veins, with obvious purplish brown or dark brown edges. This is the most common type of susceptible plaque. (2) Oval or spindle-shaped disease spot, the expansion is not limited by the vein, the disease spot is larger, grayish brown or yellowish brown, there is no obvious, dark edge, and sometimes there are wheel lines on the disease spot. It also belongs to the susceptible plaque type. (3) the small yellow-brown necrotic spot is basically not enlarged, and there is an obvious yellowish-green halo around it, which is a resistant spot. Second, spread epidemic conditional germs through airflow and Rain Water. In general, the disease spot can appear in the 2-3 leaf stage of summer maize, the disease spot is dense at 5-6 leaf, the leaf is scorched and scorched, and the incubation period of the disease is short, the number of re-infection in the growing season is more, and the damage is serious, and the corn overwinters with the diseased remains after harvest. The key to the climatic condition of the occurrence of bacteria is temperature and humidity. On the basis of having certain bacterial sources and susceptible varieties, the occurrence degree of the disease is determined by temperature and humidity. For small spot disease, for example, the temperature is stable above 25 ℃ for a long time from July to August, and the disease is serious when it is rainy and dewy. In addition, the disease of corn continuous cropping is serious, the disease is serious near the village, and the disease of straw returning to the field is serious. Third, control methods due to the large planting area of corn, and the incidence of leaf spot is wide, the disease period is concentrated, so once epidemic, it is more difficult to adopt local small measures to control. Therefore, we should focus on a wide range of prevention-based measures. 1. Remove the diseased leaves. At the initial stage of the disease, when the incidence of the lower two leaves is about 20%, the diseased leaves should be removed immediately, the diseased leaves should be taken out of the field and buried or burned, and then 3-5 leaves should be removed every 7-10 days, which has an obvious effect on controlling the spread of the disease. But it must be carried out in a large area, and the effect is obvious in a short time. Fertilize and water immediately after removing the diseased leaves to promote growth and enhance disease resistance. two。 Ploughing and hoeing. Reduce soil moisture and improve field environmental conditions. 3. Increase the application of phosphorus and potassium fertilizer, strengthen field management, and enhance plant disease resistance. 4. Chemical control. At the initial stage of the disease, 70% thiophanate-methyl wettable powder 600 times, or 25% carbendazim EC 800 times, or 10% high water dispersible granules 2500 times 3000 times, or 50% carbendazim wettable powder 600 times, once every 7 to 10 days, even 2 times for 3 times. Click to get more corn planting techniques click to get more food crop planting techniques