Latest Control Methods for Clubroot Disease in Continuous Vegetable Cropping
Vegetables are highly prone to clubroot disease when grown in continuous cropping. After infection, vegetable seedlings appear stunted, and their leaves wilt as soon as they are exposed to the sun. When the seedlings are pulled out, clusters of galls are often seen growing on the root system, and in severe cases the roots have completely rotted. So how should clubroot disease be controlled in continuous vegetable cropping? Let's take a look together.
I. Main Symptoms of Clubroot Disease
The leaves of diseased plants become pale, wilt and droop, and the roots swell into galls. Once clubroot disease reaches the late stage, there is no cure. The main cause of clubroot disease is the presence of pathogenic bacteria in the soil. Especially in fields where rapeseed and cabbage-type vegetables have been planted year after year, large numbers of resting sporangia of Plasmodiophora brassicae (the clubroot pathogen) exist in the soil. Under suitable conditions, they will revive, causing clubroot disease in vegetable seedlings.
II. Triggering Factors
1. A high-humidity environment favors the reproduction and development of the pathogen, so clubroot disease is highly likely to occur in soils with high moisture, in low-lying waterlogged fields, and in fields converted from paddy to dryland;
2. The occurrence of clubroot disease is also related to the soil. According to research findings, when the soil is acidic, the probability of clubroot disease is relatively high, while when the pH value is higher than 7.2, the disease rarely occurs.
3. The outbreak of clubroot disease is also related to trace elements. When the soil is deficient in calcium, the disease can also be triggered;
4. The pathogen spores of clubroot disease can cause disease at temperatures of 9-30 degrees, and the most suitable temperature for reproduction is 23 degrees.
III. Control Measures
1. Carry out crop rotation for more than 3 years; paddy-upland rotation is even better. In areas where clubroot disease occurs severely, it is best not to use glyphosate-type herbicides for weed control. For the seedbed, use a 400-fold dilution of 50% dexon for sterilization treatment.
2. Adjust soil acidity and alkalinity. When the soil is relatively acidic, evenly broadcast 100-150 kg of lime per mu onto the soil surface, and mix it thoroughly into the soil through land preparation.
3. When diseased plants are found, they should be pulled out promptly, and after boiling at high temperature or drying, they should be burned uniformly. Diseased plants must never be left in the field or thrown into other areas, to prevent the pathogen from spreading over a larger area. Afterward, use 1% lime solution or 1% lime solution + 1000-fold dilution of 75% chlorothalonil wettable powder to drench the planting holes for control.
The above is an introduction to how to control clubroot disease in continuous vegetable cropping. We hope it can help you. For more related knowledge, please stay tuned to us.