Common Watermelon Diseases and the Latest Control Methods
Watermelon is one of the fruits many people love to eat most, but the watermelon itself is very fragile. It is not only highly sensitive to the surrounding environment, but also encounters many diseases during its growth, and a single careless moment may endanger an entire watermelon field. So what diseases harm watermelon? Below, the editor will explain several common watermelon diseases.
1. Watermelon blight
Watermelon blight usually occurs during the hot, rainy season; poor drainage in the watermelon field and planting too densely can both trigger it. It harms the roots and stems of watermelon, and in severe cases also affects the leaves, fruit and vines. When it develops at the root crown, dark green patches appear, and the patches spread around the stem, causing the stem to rot, and finally leading to the death of the entire plant. The symptoms on leaves, fruit and vines are similar. Before sowing, disease-resistant varieties can be selected, such as Qiongxue. Never rotate with melon and fruit vegetables after the watermelon field is harvested, and diseased melons should be removed promptly to prevent transmission. When melons are affected, sprays can be applied for control, such as cymoxanil mancozeb, sprayed once a week for about one month.
2. Watermelon leaf blight
Watermelon leaf blight is a relatively common disease of watermelon, with a higher incidence in spring and autumn, mainly due to more rainy weather. Leaf blight mainly harms the leaves, and secondarily the vines and fruit. It mostly develops on young leaves, producing irregular brown patches on the young leaves, and continued growth causes the leaves to wither; when it develops on fruit and vines, the fruit and vines rot. There are special disease-resistant varieties on the market, such as Zhengza No. 7. After harvest, care should be taken to clean up diseased melons and burn them in a centralized manner. Establish a good drainage system for the watermelon field, and pay attention to rain protection during rainy weather. Before patches appear, procymidone wettable powder can be used for spray control, also once a week, sprayed for about one month.
3. Watermelon Fusarium wilt
⟦NL>Fusarium wilt generally occurs at the fruiting stage. Seedlings stand upright in a wilted state, causing all the leaves to wither, and the base of the vines rots and turns brown. This is mainly because the pathogen enters through wounds on the roots, grows inside the cells, and secretes substances such as pectinase that destroy the cells, causing the vessels to become blocked so that water and nutrients cannot be transported. The best way to control Fusarium wilt is to graft watermelon onto crops that are not prone to Fusarium wilt, such as gourds. Disease-resistant varieties on the market include Xinong No. 8. To prevent Fusarium wilt, water-loving crops can be rotated in the watermelon field, because the Fusarium wilt pathogen survives in water for only just over 100 days. Finally, choose soil rich in nutrients, and do not use fertilizer containing diseased residues.4. Watermelon gray mold
Gray mold is caused by the invasion of Botrytis cinerea and is especially severe during the rainy season in the south. It mainly harms leaves, fruit and stems; on the leaves it produces gray irregular patches, which eventually cause withering. Gray patches also appear on the fruit and stems, preventing the fruit and stems from growing normally and producing deformed fruit. Gray mold is the most serious disease of watermelon, and in the most severe cases it can cause all the watermelons in an entire field to become deformed and unsellable. Wuyi mycin aqueous solution and Fanmeibao wettable powder can be used for spraying, once a week, sprayed for about one month. Rotation should be at least more than 4 years, and abundant organic fertilizer should be used.
5. Watermelon powdery mildew
Powdery mildew mainly occurs more severely in autumn in the south, mainly harming the leaves, and generally has little effect on the fruit. Many small white particles are produced on the leaves, and these particles rob the leaves of nutrients, so that the leaves cannot grow normally and turn black. The causes of powdery mildew are mainly related to temperature, humidity and density, so attention should be paid to the temperature and humidity of the watermelon. Reasonably arrange the drainage system and planting density in the watermelon field, pay attention to drainage after rainfall, and base fertilization mainly on organic fertilizer. Powdery mildew is still mainly controlled through prevention.
The above five are several common diseases of watermelon, among which special attention should be paid to gray mold, because gray mold is difficult to control and prevent, and if it is not dealt with in time it can lead to total crop failure and no harvest at all. In fact, diseases are all closely related to temperature, humidity and density; as long as these are reasonably controlled, the probability of disease will basically be much lower.