Control measures of Maize Leaf spot

Corn leaf spot is one of the main diseases of maize, which mainly harms leaves and also harms leaf sheaths and wrapped leaves in serious cases. After the plant is susceptible, it starts from the bottom leaf and gradually expands upward. In the same leaf, large and small spots can be mixed, or multiple disease spots are connected to each other. When the disease is serious, the leaves dry up, chlorophyll decreases, photosynthesis decreases, and grain filling is affected. The yield of general plots is reduced by 15%, and the serious yield reduction is more than 50%, which has a great impact on the yield of corn. Therefore, departments at all levels should attach great importance to maize leaf spot and introduce corresponding control measures to control the disease in the initial stage.

Corn leaf spot

Maize leaf blight, also known as maize leaf blight and maize leaf streak, is one of the most important diseases in maize, which mainly damages the leaves, leaf sheaths and bracts of maize, and the leaves suffer the most. In the field, the disease usually starts from the lower leaves and gradually spreads to the upper leaves. At the initial stage of the disease, water-stained bluish-gray spots first appeared on the leaves. After that, it gradually spread along the leaf veins to both ends, forming a large prism-shaped spot with a brown edge in the center, and longitudinal cracks often appeared in the later stage. After most of the disease spots were connected, the leaves turned yellow and withered, and in severe cases, the whole plant turned yellow and withered early. When the weather is wet, there are a large number of gray-black mold layers on both sides of the disease spot, and sometimes on the filaments or male flower glumes. The pathogen of corn leaf spot belongs to semi-known fungi, Alternaria, dark spore family. The general temperature is 20 ℃ ~ 25 ℃. The relative humidity above 90% is beneficial to the development of the disease. Control was carried out before and after the heading of corn and when the rate of diseased leaves reached 20%.

Corn leaf spot is commonly controlled by the following methods:

1. Spray 50% carbendazim wettable powder 500 times per mu.

2. Spray 50% thiophanate methyl wettable powder 600 times per mu.

3. Spray 500 times of 50% dimethrin wettable powder per mu.

4. Spray with 75% chlorothalonil wettable powder 800 times liquid per mu.

5. Spray with 25% carbendazim EC 800 times per mu.

6. Use 90% mancozeb wettable powder 500 times liquid spray per mu. Spray once every 7-10 days for a total of 2-3 times.

Maize leaf spot

Maize leaf spot, also known as maize spot disease, is one of the important diseases in maize, which mainly damages the leaves, leaf sheaths, bracts and ears of maize. The leaf damage is the most serious, and the disease occurs for a long time, and can be damaged from seedling to near maturity. The disease is usually serious before and after the heading stage and filling stage, and the leaf disease spot is smaller, but the number of disease spot is more than that of big spot disease. After the disease, the diseased leaves are easy to wilt and die. The pathogen of maize leaf spot is the same as that of maize leaf spot, the general temperature is 20 ℃ ~ 25 ℃ and the relative humidity is above 90% is beneficial to the development of the disease. Prevention and control was carried out when the rate of diseased leaves reached 20% before and after the heading of corn. The method of control is roughly the same as that of maize leaf spot.