What specific-effective pesticide works well for preventing and controlling muskmelon leaf blight
Muskmelon is a common fruit and was the earliest cucurbit used as a fruit in China; its leaves are thick and papery, rough on the upper surface, and covered with white stiff hairs. Muskmelon leaf blight is one of its main diseases. So, what is the specific-effective pesticide for muskmelon leaf blight?
1. What is the specific-effective pesticide for muskmelon leaf blight?
During the fruiting stage, before watering or when it first clears after rain, spray with 75% chlorothalonil wettable powder at 800 times dilution or 1:1:200 Bordeaux mixture to prevent the disease; after diseased plants are found, spray with 25% Kairun emulsifiable concentrate at 3000 times dilution, 80% Yunsheng wettable powder at 600 times dilution, 60% Baitai water-dispersible granules at 1000 times dilution, 72.5% Yunda Baisite wettable powder at 600 times dilution, or 50% iprodione at 1500 times dilution for control, spraying once every 6-8 days, for 3-5 consecutive sprays.
2. Symptoms of muskmelon leaf blight
It mainly occurs during the growing period. The disease mainly harms leaves and occasionally also harms leaf stalks. In the early stage of the disease, small yellow-green spots appear on the leaves, which then expand into round to oval brown lesions with a grayish-white center, dark brown to purplish-brown edges, slightly raised, and an oil-soaked-looking outer margin. Later, sparse mold develops in the center. The lesions are about 0.1-0.2 mm in size, and there are many spots on diseased leaves; a single leaf often has more than 300 lesions. In severe cases, the leaves curl and die, and the diseased plants turn reddish-brown. This disease begins to appear in the late fruit-setting stage and reaches its peak when sugar accumulates, usually occurring on the upper-middle leaves. When stems and vines are affected, diamond-shaped or oval slightly sunken lesions are produced. When fruit is affected, round brown sunken spots appear on the fruit surface, often with cracks, and the pathogen can gradually invade the flesh, causing the fruit to rot.
For muskmelon leaf blight, fellow farmers must not neglect early prevention. Before sowing, seeds can also be soaked for 2 hours in 75% chlorothalonil wettable powder or 50% iprodione wettable powder at 1000 times dilution.