What are the plant diseases of watermelon? How can it be prevented?

Watermelons are susceptible to anthracnose, vine blight, leaf blight, root rot, etc. Once the plant is found to be sick, it should be sprayed evenly on the leaves of the plant with a special insecticide, and it should not be watered during the medication, otherwise it will have no effect.

There are five common diseases of watermelon: gray mold, powdery mildew, wilt, leaf blight, and watermelon blight. Botrytis is caused by the invasion of Botrytis cinerea, which can be sprayed with a drug.

Powdery mildew is more serious in autumn, pay attention to temperature and humidity, and reasonably arrange the drainage system and planting density to prevent it. The best way to do wilt is to graft onto crops that are less susceptible to wilting, such as gourds. There are special disease-resistant varieties in the market for leaf blight and watermelon blight, such as Zhengza No. 7, Qiongxue, etc.

The first is common, this aphid is very scary, so we must pay attention, the second point is that there is that kind of locust will make the whole watermelon rotten, so we must prevent the spraying of some related pesticides in time, the third point is that you can use some related sprays to prevent, the effect is very good.

Choose the best varieties. The selection of varieties should be correct, mainly according to the watermelon varieties cultivated over the years, and the watermelon varieties with the strongest adaptability, the highest yield and the best quality should be selected for the local climate, soil quality and fertilizer.

1. Sow seeds at the right time. Cultivate stout melon seedlings. The key to cultivating stout seedlings is to sow seeds in a timely manner, and use a new high-fat film to dress seeds (which can be mixed with seed coating agent) before sowing, which can repel underground pests and diseases, isolate virus infection, do not affect the germination and swelling function, strengthen respiratory intensity, and improve seed germination rate.

Take a hotbed agricultural film arch shed for seedlings raising. In the middle and late stages of seedlings, more exposure and less covering, day and night cover, 3-5 days before transplanting, can be unveiled and refined seedlings around the clock, so as to help cultivate healthy and thick melon seedlings.

2. Apply sufficient base fertilizer. Watermelon requires a large amount of fertilizer, therefore, applying enough high-quality base fertilizer is the basis for obtaining high-quality, stable and high-yield watermelon. 1500-2000 kg of rotting fertilizer needs to be applied per mu, and 25-30 kg of compound fertilizer (watermelon special compound fertilizer is better).

The fertilization method can be changed from the previous single furrow fertilization to double furrow fertilization, that is, on both sides of the middle of the compartment surface that are 30-40 cm apart, each open a deep and wide ditch of 20-30 cm, and then apply fertilizer into two furrows, cover the soil about 5 cm, and the melon seedlings are planted in the middle of the two fertilizer ditches. The advantages of this kind of fertilization are: do not burn seedlings, and prevent growth, timely spraying to promote Kao No. 3, can transform plant vegetative growth into reproductive nutrition, inhibit the crazy growth of the main shoot, promote flower bud differentiation, more flowering, improve the quality of pollen fertilization, more flowering, more fruit set, prevent fruit dropping, and promote development.

3. Scientific top dressing. Under the premise of applying plantar fertilizer, only 200 kg of human feces and urine need to be applied once during the vine extension period, and 3 kg of urea is added. Because the watermelon is very sensitive to water and fertilizer during the flowering and fruit-setting period, if the fertilizer and water are excessive at this time, the plant will have excess nutrition, which is easy to cause overgrowth, which is an obstacle to the melon.

Therefore, when the young fruit is as big as an egg, it can be topdressed appropriately, combined with the spraying of strong guati to thicken the guadi, strengthen the amount of nutrient directional delivery, promote the rapid development of the melon body, and the melon shape is beautiful and delicious; The growth cycle does not drop flowers, does not fall melons, does not crack melons, and does not deform melons. When the watermelon swells, the root system just extends to the two fertilization furrows, and the nutrients are sufficient, which is conducive to rapid growth into a large melon with a standard melon shape.

4. Pest control. Cataplexy, blight, and anthracnose are the three main diseases of watermelon. To prevent and control cataplexy at the seedling stage, pay attention to ventilation and control watering in the seedbed.

Fusarium wilt and anthracnose prevention and control methods: avoid continuous cropping, generally interval of 4-5 years, do a good job of ditch cleaning and drainage, and find that the diseased plants are uprooted in time. Pharmaceutical prevention and control:

Spraying with 75% chlorothalonil wettable powder, or 70% dixone, or 20% sparkling, or Bordeaux liquid, the control effect is very good. Watermelon insect pests mainly include: yellow gourd, ground tiger, aphid and red spider at the seedling stage.

The pesticide control method is to use dichlorvos, dimethoate, trichlorfon and carbofuran respectively, and the effect is better.

I couldn't say a few words clearly, I went to the bookstore to buy watermelon planting books, and Jindun Publishing House published more books on agricultural technology.

Watermelon diseases mainly include: watermelon soft rot, vine blight, watermelon umbilical rot, watermelon coal stain disease, watermelon flower rot, etc.

Watermelon soft rot and vine blight: mainly damage stems, vines, and fruits. The stem and vine infection is mostly caused by the wound, the lesion is irregularly shaped and water-stained, and the inward soft rot develops rapidly, which can cause the soft rot of the whole plant, and has a foul smell like stinky pickles, and the yellow-white bacterial pus flows out of the section of the diseased vine.

The fruit is damaged, and the water-stained dark green spots appear at the beginning, which are slightly concave after enlargement, and the diseased part is soft and gradually turns brown, and there is a water-stained halo around the lesion, which rots inward from the diseased part and exudes a foul odor. Spray 72 agricultural streptomycin sulfate soluble powder + new high-fat film 800 times liquid for control.

Watermelon umbilical rot: generally at the top of the fruit (umbilicus) initially water-soaked, dark green or dark gray, with the development of the disease soon changed to dark brown, the flesh loses water, the top is flat or concave, generally not rotten, when the air is humid, the diseased fruit is often saprophyte by some fungi. The soil has low salt content, acidification, insufficient calcium supply to the soil, and water imbalance is prone to disease.

Spray 0 1 0 3 calcium chloride or calcium nitrate water + 800 times of new high lipid film every 7 days, 2 3 times a week can be prevented; At the same time, before flowering, young fruit stage and expansion stage, Zhuang Gua Ti Ling was sprayed to increase the thickness of melon stem, increase the amount of nutrient delivery, coordinate the nutrient balance, and improve the yield of watermelon.

Watermelon coal stain disease: the pathogen mainly leaves mycelium and conidia on the ground with the disease residue for wintering, and the climatic conditions are suitable for re-infection by wind and rain propagation in the following year, and the leaves produce gray-black or carbon-black colonies in the early stage of the disease, which are coal-stained, and are sporadically distributed in the leaf surface or near the leaf veins at the beginning, and cover the entire leaf surface in severe cases; The disease is easily induced by the dense planting of the plants, the growth of the canopy between the plants, the high humidity in the field or the pests of whiteflies and aphids. Spray 50 carbendazim wettable powder + 800 times of new high-lipid film for prevention and control.

Watermelon flower rot: It mainly occurs in the watermelon cultivation areas in southern China, especially in the watermelon fruiting period in high temperature and rainy years, which has a great impact on watermelon production. It is mainly to damage the residual flowers of the umbilicus of the young fruits, causing flower rot, and often cause the disease of young fruits near the residual flowers when further expanding, which is water-stained soft rot, and seriously causes the whole fruit to rot, and when the humidity is high, the disease grows gray-white wool-like and gray-white to black-brown heads, which seriously affects the commodity value of watermelon.

In the area with severe disease, 80 allicin (antibacterial agent 402) emulsifiable concentrate + 800 times of new high-lipid film should be sprayed at the first flowering stage for prevention and control.

Intercropping, intercropping, no crop rotation (especially melons).

Strengthen management and chemical control, the main diseases are anthrax and wilt, which are not very difficult to treat.