Pictures and treatment of corn leaf spot

Agricultural control: remove the diseased leaves in the lower part of the diseased plant and pay attention to drainage in low-lying plots. Timely fertilization: 10-20 kg chemical fertilizer was applied from jointing to heading stage of corn. Chemical control: 30% hexazolol suspension 15 g, 10% Bacillus subtilis 30 g, 50% carbendazim wettable powder 500-600 times. Increase application of phosphorus and potassium fertilizer: spray potassium dihydrogen phosphate.

I. Agricultural prevention and control

1. Corn leaf spot, large leaf spot and gray leaf spot are the main diseases in maize production, which are commonly referred to as leaf spot, often mixed, with moderate occurrence, mainly harmful leaves and bracts, irregular and transparent spots, grayish white in the center, brown on the edge, and upper black spots, that is, the ascomycetes of pathogens, mainly distributed in Jilin, Liaoning and Henan provinces.

2. If there are more Rain Water this year, the fertilizer damage will be a little more serious than in previous years, so it is necessary to actively do a good job in the prevention and control of maize leaf spot, which is helpful to improve the yield and quality of corn.

3. During this period, the diseased leaves in the lower part of the diseased plant need to be removed in time to strengthen the management of the middle and later stage of the corn field, which can be ploughed and weeded, and the low-lying land needs to pay attention to drainage, which is helpful to improve the microclimate environment of the corn field and enhance the disease resistance of the plant.

Second, timely fertilization

From jointing to heading stage, 10-20kg fertilizer can be applied properly to improve the resistance of maize varieties and control and reduce the harm of maize leaf spot.

III. Chemical control

1. Corn leaf spot disease needs to be prevented as soon as possible, and focus on prevention of susceptible varieties and diseased fields over the years. Usually if sporadic diseased plants are found in corn planting fields, it is necessary to carry out chemical control to control the disease center in order to reduce the spread of germs.

2. Medicaments can be taken to prevent and cure the disease in time in the early stage of the disease. during this period, 30% hexazolol suspension 15g, 10% Bacillus subtilis 30g, 50% carbendazim wettable powder 500-600 times, 75% chlorothalonil wettable powder 600-800 times, 65% Dysen zinc wettable powder 400-500 times, and methyl thiophanate (methyl thiophanate), propiconazole, oxyedazole (Shigao) and other agents can be sprayed with water.

3. Generally spray the medicine once every 7-10 days and prevent and cure it for 2-3 times successively. You can choose to apply it on a sunny day. After applying the medicine, it must ensure that it will not rain for more than 5 hours before it can be effective.

IV. Increase the application of phosphorus and potassium fertilizer

1. Generally speaking, for the corn plots with phosphorus deficiency symptoms, appropriate amount of potassium dihydrogen phosphate can be sprayed to supplement trace elements, which is beneficial to improve the resistance of corn.

2. For the seriously affected plots, after the disease is controlled, potassium dihydrogen phosphate or other foliar fertilizer can also be sprayed to promote the growth of corn as soon as possible, so as to improve the yield and quality of corn.