How to Treat Powdery Mildew on Melons? A Detailed Guide to Prevention and Control Methods

Melon is a common fruit in summer, and powdery mildew is one of the most common diseases. If you want to ensure the normal growth of melons, you need to prevent and control powdery mildew in time. So how do you treat powdery mildew on melons?

1. How to prevent and control powdery mildew on melons?

1. Choose resistant varieties. Disease resistance varies noticeably among different melon varieties, so choosing resistant varieties is the key to controlling the degree of disease occurrence.

2. Clean the field. After the crop is harvested, weeds and residues should be removed in time. During the melon growing period, weed in time, remove diseased leaves, and take weeds, residues, and diseased leaves outside the field to be burned in a centralized manner.

3. Manage scientifically to enhance plant disease resistance. Apply sufficient base fertilizer, especially heavily apply decomposed organic fertilizer, and plow deeply and harrow finely; prevent excessive vegetative growth and premature aging of plants, organize vines in time, and strengthen ventilation and light penetration; pay attention to applying phosphorus and potassium fertilizer as a top dressing during the mid-growth stage, and use foliar fertilizer well to cultivate robust vines and enhance population disease resistance.

4. Irrigate scientifically. Create environmental conditions suitable for melon growth and unfavorable for the occurrence and development of powdery mildew. Four principles should be mastered for irrigation: do not water on cloudy days but water on sunny days, do not water in the afternoon but water in the morning, do not water heavily but water lightly, and do not water openly but water in a concealed way (that is, concealed irrigation under the film).

5. Chemical control. Choose 15% triadimefon wettable powder 1000-1500 times solution, or 40% Daconil suspension concentrate 800-1000 times solution, or 40% Fuxing emulsifiable concentrate 6000 times solution, or 10% Shigao water-dispersible granules 2000 times solution, or 30% Tefuling wettable powder 5000 times solution, or 50% thiophanate-methyl wettable powder 1000 times solution, etc., and spray them alternately in rotation for control, spraying once every 7-10 days for 2-3 consecutive sprays. Medication is prohibited 7 days before melon harvest to allow safe harvesting.

2. Symptoms of powdery mildew

It mainly damages leaves, and also damages petioles and stems and vines. In the early stage of the disease, small powdery mildew spots appear on the upper surface of the leaves, then spread to the underside of the leaves, and quickly expand to form a powdery layer. In severe cases, it extends to the underside of the leaves, stems, and petioles. When stems and vines are infected, as with the leaves, small white powdery spots first appear on the stems and vines, and finally the entire stems and vines are covered with powdery mildew. In the late stage of the disease, the entire plant is covered by a powdery layer, after which the powdery layer turns grayish white, and scattered or clustered yellowish-brown small granular spots appear in the powdery layer, later turning black, which are the cleistothecia of the sexual generation of the pathogen. Diseased leaves become scorched, dry, and brittle, causing the fruit to grow slowly in the early stage. After healing, traces will also remain at the lesion sites.

Powdery mildew is a common disease. As long as prevention and control work is done well, the harm caused by powdery mildew can be greatly reduced, effectively ensuring melon yield.