How to prevent and control melon pests and diseases? Latest technical methods tutorial

Melon, also known as gan melon, xiang melon, etc., with the adjustment of the planting industry structure and the rapid development of high-efficiency agriculture, the area planted with small sheds, medium sheds, large sheds, and greenhouses for watermelons and melons has increased year by year. Due to continuous years of repeated cropping, disease sources and insect sources have accumulated year by year, causing the types of pests and diseases to increase year by year and the degree of damage to worsen year by year. Now let us take a look together at the pest and disease prevention and control techniques for melons!

Phytophthora blight

[Damage characteristics] Phytophthora blight is a major disease of watermelons and melons from the seedling stage to the vine-running stage. When leaves are infected, dark green water-soaked irregular lesions first appear, then expand into a soft rot form. When dry, the lesions turn brown and break easily. When the stem base is infected, spindle-shaped dark green water-soaked sunken lesions first appear, then constrict and rot around the stem base, and finally the plant dies.

[Prevention and control methods] Disinfect seeds before sowing by soaking them in 55°C warm water for 15 minutes. Sterilize the nutrient soil by adding 2 liang of 50% carbendazim per cubic meter of nutrient soil and mixing well. Apply chemicals in the early stage of disease onset: spray with 64% oxadixyl-mancozeb at 500 times, 72.2% propamocarb at 800 times, or 58% redomil (metalaxyl-mancozeb) at 500 times, and spray again after 7-10 days.

Gummy stem blight

[Damage characteristics] Gummy stem blight mainly occurs on leaves and stems. When leaves are infected, nearly circular lesions first appear, or light brown “V”-shaped lesions extend inward from the leaf margin. Later the lesions break apart, and many small black dots, namely pycnidia, form on them. When stems are infected, oval to spindle-shaped lesions first appear, then dry and shrink with longitudinal cracking and exude yellow gum. In severe cases, leaves dry up and stems rot.

[Prevention and control methods] Avoid watering on cloudy days and try to ensure continuous sunny days after watering. If continuous rainy days occur after watering, pay attention to short-term dehumidification at noon. In the early stage of disease onset, spray with 75% chlorothalonil at 600 times, or 70% thiophanate-methyl at 800 times + 80% dasen (or yuesheng) at 800 times. After harvest, promptly remove diseased residues to reduce inoculum sources.

Anthracnose

[Damage characteristics] The disease can occur throughout the entire growth period. When leaves are infected, circular to spindle-shaped or irregular water-soaked spots first appear, sometimes with concentric rings. When dry, the lesions break easily and perforate. When moist, pink sticky material appears on the leaf surface. When petioles or stems are infected, water-soaked pale yellow circular spots first appear, slightly sunken, then turn black. In severe cases, they encircle the stem and cause death. When fruits are infected, water-soaked sunken brown lesions first appear, and the sunken areas often crack. When humidity is high, pink sticky material forms in the center of the lesions. In severe cases, the lesions merge and the fruit rots.

[Prevention and control methods] Select disease-resistant seeds and disinfect seeds with warm water. In the early stage of disease onset, spray with 70% thiophanate-methyl at 800 times, 75% chlorothalonil at 600 times, or 80% anthracnose fumei at 800 times, and spray again after 7-10 days.

Bacterial angular leaf spot

[Damage characteristics] Bacterial angular leaf spot is a mid-to-late stage disease of cucurbits and mainly occurs on leaves. In greenhouse watermelon fields, the general diseased plant rate is about 25%, with the highest reaching 70%, and the diseased leaf rate is about 10%. After leaves are infected, tiny transparent pinpoint-sized spots first appear, and after expansion they form pale yellow lesions with yellow halos. The center turns brown or becomes grayish white and perforates and ruptures. When humidity is high, milky white bacterial ooze is produced on the diseased parts.

[Prevention and control methods] Select disease-free seeds and disinfect seeds with warm water. In the early stage of disease onset, spray with 13% copper ammonia complex aqueous solution at 300 times, 50% DT (copper succinate) wettable powder at 500 times, 77% keshade powder at 400 times, or 72% agricultural streptomycin wettable powder at 400 times, and spray again after 7-10 days.

Powdery mildew

[Damage characteristics] Powdery mildew mainly damages leaves. In the early stage of disease onset, white nearly circular star-shaped small powdery spots appear on the upper surface of leaves, then expand around to form continuous white powder with indistinct edges. In severe cases, it covers the entire leaf, later turns gray-black, and the diseased leaves turn yellow and dry up.

[Prevention and control methods] Implement alternate watering in large and small furrows, ventilate promptly on sunny days, pay attention to dehumidification on cloudy days, and promptly pinch off growing tips and remove old leaves to avoid field shading. In the early stage of disease onset, use 4 grams (1 bag) of 40% DuPont “Fuxing” emulsifiable concentrate per mu, or 0116 biological pesticide at 150 times diluted with water for spraying.