Symptom Identification and Control Methods for Clubroot in Chinese Cabbage

Chinese cabbage is grown very widely; it tastes fairly sweet and is quite affordable. But don't let its low price fool you, as there are quite a few Chinese cabbage growing bases in our country. However, when growing Chinese cabbage, many pests and diseases can appear, and clubroot is one of them. Clubroot causes Chinese cabbage to become stunted with yellow leaves, and the roots become severely deformed, and the fungus can persist for more than ten years. So what are the symptoms of clubroot? How should it be controlled? Let's take a look!

1. Disease Characteristics

Clubroot is a fungal disease, and in the early stages of infection it cannot be observed normally. The fungus invades the roots of Chinese cabbage, causing tumors of various sizes to appear on the roots. About half a month after infection, the plants above ground gradually wilt, grow extremely slowly, and in the later stage simply stop growing. Then the leaves gradually turn yellow and show symptoms of water deficiency. This is the time when growers are most easily misled; many people think it is caused by a lack of water. In fact, it is because the root tumors are too large, making normal water uptake impossible, which produces the symptoms of water deficiency.

2. How to Diagnose

There are only two causes of tumors appearing on the roots of Chinese cabbage. The first is damage to the roots caused by root-knot nematodes, which bore into the roots of Chinese cabbage and gradually cause the roots to swell. If you pull up a diseased plant and find no root-knot nematodes, microscopy can be used. If 5-6 sided fungal bodies are found, it is highly likely to be Plasmodiophora brassicae, the pathogen that causes clubroot. Plasmodiophora brassicae mainly lurks in the soil and then spreads through diseased plants, water and various other media, causing clubroot to occur on a large scale in Chinese cabbage.

3. Patterns of Occurrence

Among pests and diseases, clubroot has a relatively low incidence, but experimental surveys show that in recent years there have been cases of clubroot in various places, and the number is still rising. Plasmodiophora brassicae can survive in the soil for a very long time, and whenever cruciferous vegetables are planted, it will cause disease at irregular intervals. It can also spread by means of the flow of water and fertilizer in the soil and by various insects. The disease is especially severe in rainy weather and when the field is relatively moist. Spring each year is the peak period for clubroot.

4. Control Methods

First, when selecting seeds, we need to choose varieties with strong disease resistance, and then disinfect and sterilize the seeds well; a dual powder seed dressing agent can be used for seed dressing. Continuous cropping must not be practiced, and planting should be avoided as much as possible if the previous crop in the soil was a cruciferous plant. For rotation, some melon and fruit vegetables and fruits can be planted. The planting plot must be disinfected; agents such as Fushuaide suspension concentrate can be mixed into the soil before sowing. Do a good job of preventive work, disinfect regularly and strengthen the management of the vegetable garden.

The above is an introduction to clubroot. You may not be very familiar with clubroot because its incidence is relatively low. But in recent years the incidence rate has gradually increased, and the level of harm from clubroot can be said to rank among the top few among diseases. The editor also hopes everyone can pay attention to it, which is why I specifically introduced clubroot. That is all for today's article. This article is for reference only, and I hope it is helpful to everyone.