What symptoms does cauliflower leaf blight have? How to prevent and cure it?

Cauliflower, also known as Golden Needle, Lemon Hemerocallis, forgettable grass, is not only a kind of sun-dried cooking, but also can be used as a tonic medicine, with calming, hemostasis, digestion, vision and other functions. Cauliflower is mainly planted in Shanxi, Shandong, Anhui, Zhejiang, Hunan, Liangguang and other places in China, and leaf blight is easy to occur in the planting process. What are the symptoms of cauliflower leaf blight? How to prevent and cure it?

What are the symptoms of cauliflower leaf blight?

Leaf blight begins to occur from yellow flower seedlings, mainly harms leaves and flower moss, has an obvious disease center and can spread in all directions. First of all, there are small watery brown spots on the tip or edge of the leaves, and then become gray-white in the center, brown around, and small spots with yellowish-green halos. The disease spot expands longitudinally rapidly, forming brown stripes, and there is still a clear halo. The disease spots are connected, so that the leaves change from yellow to brown and die, and many small black spots can be seen in the dead part. At the same time, the new leaves were constantly infected so that the whole plant was seriously dead, and finally the whole plant withered, did not draw flower moss, even if sporadic bolting, it was extremely dwarfed, and the buds were few and small. The disease generally began in late April in the field, and accelerated from May to June, with heavy rain, high temperature and serious damage caused by spider mites, the harm of the disease will also be aggravated.

Second, how to control the leaf blight of cauliflower?

1. The planting fields were turned over to loosen the soil, fertilized and irrigated, and sprayed with new high-fat film to induce new roots, strengthen root function, improve soil physical and chemical properties, improve soil structure, keep warm and prevent cold, and ensure that cauliflower survived the winter safely.

two。 The improved varieties with high yield and disease resistance were cultivated and the disease and residues in the field were removed in time in the growing season of cauliflower in order to effectively reduce the infection source of rust in the field.

3. Renew the old plant cluster in time, dig the soil 30cm or so deeply, remove part of the old root, promote the autumn seedling ramet and renew the over-old seedling age in time to improve the plant resistance.

4. Strengthen the management of appropriate irrigation, pay attention to clear ditches and drainage, improve root activity, spray Zhuangjianling at the initial stage of bolting, can make cauliflower stalks stout, buds strong, plants luxuriant, and improve the rate of high-quality goods.

5. Reasonable ventilation to reduce the humidity in the greenhouse before 10:00 in the morning on a sunny day, the effect of new high lipid film combined with pesticides is the best, which can shield the sense of smell of pests and inhibit the replication of germs. reduce its drug resistance and dosage, but also control the volatilization of pesticides and improve the control effect many times.

6. In the growing season, spraying medicine every 10 days or so from the early days of the disease in late June to October can effectively prevent and cure the disease. The commonly used medicaments are 100 times Bordeaux solution, 50% topiramine 500800 times, 50% carbendazim wettable powder 1000 times (or 40% gel suspension 600,800 times), 50% benzoate 1000-1500 times, 65% Dysen zinc 500 times, etc., which can be used alternately or alternately.