Multiple measures to Control Cotton Seedling Disease

As the cotton sowing period and after the emergence of Rain Water has been continuous, resulting in the death of seedlings this year is more serious than in previous years, the most serious has begun to destroy seeds.

1. Main symptoms

After cotton seedlings are unearthed, yellow-brown disease spots appear at the base of the stem (where they meet the land), gradually protect large, sunken, rot, the color becomes black and brown, and the cotton seedlings die, which is a typical "blight disease", which is commonly known as "black neck" disease by cotton farmers.

Second, the cause of seedling death

1. The sowing date is early and the temperature is low. According to the forecast of the meteorological department, the temperature in April 2008 was 3-5 ℃ lower than that of previous years, but most cotton farmers did not postpone the sowing date according to the temperature, or even advanced the sowing date, resulting in slow emergence of cotton seedlings, long infection time and serious disease.

two。 Rain Water has a lot of humidity. The resistance of cotton seedlings was the weakest within 15 days after being unearthed, and the disease of low temperature and high wet seedlings occurred seriously. Since late April this year, Rain Water has been soaking cotton seedlings in Rain Water, and the roots can't breathe. Too much humidity causes the occurrence of seedling disease and the death of cotton seedlings, and the disease is the most serious in cotton fields with low-lying terrain, poor drainage and heavy soil.

3. The stubble is serious. As most of the cotton in our province is planted year after year, the number of pathogens in the field is too much, and the number of beneficial bacteria is too small, resulting in serious seedling disease.

4. The quality of cotton seed coating agent does not pass. Many seed coating agents are written to be insect-resistant and disease-resistant, but cotton seedlings are neither disease-resistant nor insect-resistant after they are unearthed, resulting in great occurrence of diseases and insect pests.

III. Prevention and control methods

1. Seed treatment. When replanting, destroying seeds, or sowing wheat and interplanting cotton or sowing cotton in summer, due to the current low ground temperature and high humidity, we must do a good job in the prevention of seedling disease. Before sowing, 1.5 kg cotton seeds can be mixed with Gaoqiao 10 ml and 50 grams of probiotics, and the seeds can be treated or coated twice, which can effectively control the continuous cropping disease, make the cotton seedlings sturdy, control the incidence of seedling disease below 10%, and do not produce aphids for 50-60 days.

two。 Agricultural prevention and control. After the rain, it is necessary to take measures to pull out the soil to dry the roots of cotton seedlings, reduce the humidity of the roots of cotton seedlings, increase the ground temperature and reduce the occurrence of diseases; in Rain Water's too large area, it is suggested to take measures such as removing film to reduce humidity and protect seedlings after sunny days.

3. Chemical control. It is necessary to spray the roots and stems in time for the cotton fields that have suffered from the disease and seriously affected. The effective agents are Ruimiaoqing 2000 times liquid + probiotics 2000 times liquid or Rimiaoqing 2000 times liquid + Bihuo 10000 times liquid, which can effectively control the phenomenon of dead seedlings.

4. Treat aphids in time. Choose agents with a long effective period to control aphids, such as using 600 times liquid this year or 3000 / 6000 Le, you can achieve a lasting period of more than 20 days.