Melons are also known as sweet melons, muskmelons, etc. With the adjustment of the planting industry structure and the rapid development of efficient agriculture, the area of ??watermelons and melons planted in small sheds, medium sheds, greenhouses, and greenhouses is increasing year by year. Due to repeated cropping year after year Planting, the sources of disease and insect pests accumulate year by year, resulting in an increase in the types of diseases and insect pests year by year, and the degree of damage is aggravated year by year. Let’s take a look at the pest control technology of melon!
Phytophthora disease
Damage characteristics Phytophthora disease is the main disease of watermelon and muskmelon from the seedling stage to the clump stage. The infected leaves initially develop dark green water-soaked irregular lesions, which later expand into soft rot. When dry, the lesions turn brown and easily break. The base of the stem is infected with the disease. The primary spindle-shaped dark green water-soaked sunken lesions then surround the stem base and shrink and rot, and finally die.
Prevention and control methods include disinfecting seeds before sowing, soaking seeds in warm water at 55°C for 15 minutes, and sterilizing the nutrient soil. Add 2 ounces of 50% carbendazim per cubic meter of nutrient soil and mix well. Use medication at the early stage of the disease, with 64% Spray with 500 times antiviral vitriol, 800 times 72.2% Precox or 500 times 58% Redomir, and spray again every 7-10 days.
Vine blight
Damage characteristics: Vine blight mainly occurs on leaves and stems. The leaves are infected with nearly round lesions or V-shaped light brown spots from the leaf edge inward. In the later stage, the lesions are broken, and many small black spots are formed on them, which are pycnidia. The diseased stems initially develop oval to spindle-shaped lesions. In the later stage, the lesions shrink and crack vertically, and yellow gelatinous material overflows. In severe cases, the leaves dry up. , stems and vines rot.
Prevention and control methods: Avoid watering on cloudy days, and try to keep the weather clear after watering. If it rains continuously after watering, pay attention to short-term dehumidification at noon. In the early stage of the disease, use 75% chlorothalonil 600 times, or 70 Spray % thiophanate methyl 800 times and 80% Dasheng (or Yuesheng) 800 times to remove diseased and dead bodies in time after harvest to reduce the source of bacteria.
Anthracnose
Damage characteristics: The disease can occur throughout the growth period. The infected leaves initially develop round to spindle-shaped or irregular water-soaked spots, sometimes with ring patterns, and the disease occurs when the leaves are dry. The spots are easy to break and perforate. When it is wet, a pink sticky substance appears on the leaf surface. The petioles or stem vines are initially infected with water-soaked round light yellow spots that are slightly sunken and then turn black. In severe cases, they surround the stems and vines and die. Fruits are infected and are initially water-soaked. The lesions appear as sunken brown lesions, and the depressions are often cracked. When the humidity is high, a pink sticky substance will appear in the middle of the lesions. In severe cases, the lesions will rot into pieces.
For prevention and treatment methods, choose disease-resistant seeds, scald the seeds and disinfect them. In the early stage of the disease, use 70% thiophanate methyl 800 times, 75% chlorothalonil 600 times, or 80% anthracnose 800 times spray, every 7 -Spray again in 10 days.
Bacterial angular spot
Damage characteristics Bacterial angular spot is a mid- to late-stage disease of melons. It mainly occurs on leaves. In greenhouse watermelon fields, the general disease rate is 25%. About 70%, up to 70%, and the diseased leaf rate is about 10%. After the leaves are infected, small transparent spots the size of pintips will appear initially, which will expand to form light yellow lesions with yellow halos. The center will turn brown or be grayish white with holes and ruptures. When the humidity is high, The diseased area produces milky white bacterial pus.
For prevention and treatment methods, disease-free seeds should be selected, and the seeds should be warmed and disinfected. In the early stage of the disease, use 13% copper ammonia solution 300 times, 50% dt (copper succinate) wettable powder 500 times, and 77% soluble Kill the powder 400 times, or spray 72% agricultural streptomycin wettable powder 400 times, and spray again every 7-10 days.
Powdery mildew
Damage characteristics Powdery mildew mainly damages leaves. In the early stage of the disease, small white nearly round star-shaped powdery spots appear on the front of the leaves, and then expand to form contiguous white powdery spots with unobvious edges. , in severe cases, the entire leaf will be covered, and later it will turn gray-black, and the diseased leaves will turn yellow and wither.
Prevention and control methods include watering in large and small ditches, timely ventilation on sunny days, pay attention to moisture removal on cloudy days, and remove old leaves in a timely manner to avoid blinding in the field. In the early stage of the disease, use 4 grams of 40% Dupont Fuxing EC per mu (1 bag) , or 0116 biological pesticide 150 times mixed with water spray.