First, the symptoms of bitter gourd blight in the early spring when the nursery easy to occur, the main damage stem base or underground roots. At the beginning of the disease, oval or irregular dark brown lesions appeared at the base of the stem, gradually sinking to the inside, the edge is more obvious, spread around the stem after a week, causing the stem to shrink and dry after the melon seedlings die, but not collapsed. Most of the roots were infected near the surface roots, and the cortex turned brown or rot. In the seedbed, only the individual guajava seedlings began to wilt during the day and recovered at night. After repeated days, the diseased plants wilted and died, and it was not easy to distinguish between the early stage and the damping-off disease. However, after the disease has spread, the diseased plant does not trip over, and the diseased area has a rosy or slightly obscure spidery filamentous mold, which is the mycelium or sclerotia of the pathogen, and the disease progresses slowly, which is different from damping off.
Second, control methods
1, select suitable varieties to reduce the incidence. Jiangmen big top bitter gourd, Penang bitter gourd, Suixin No. 2, Xiafeng No. 2, Xiang bitter gourd, Biqing No. 2 bitter gourd and other heat-resistant varieties were selected.
2, seed treatment to cultivate strong seedlings. The bitter gourd seed coat is thick and hard, and it is difficult to emerge in early spring when it is under low temperature conditions. It is poor in uniformity and stays in the soil for a long time. Therefore, the mechanical breakage method should be used before sowing and the clamps should be used to clamp the seed shells, but the seed shells cannot be removed and the germination potential can be significantly enhanced. Before sowing, the seeds were soaked in warm water of 56°C and allowed to cool down to room temperature. The seeds were then soaked for 24 hours and then germinated under the conditions of 30-32°C. The seeds were sown when they were 3 mm long. In order to cultivate strong seedlings to prevent cataplexy, a layer of nutritive soil should be covered after sowing. After the water is filled with water, the cover film should be kept moist and moist, and 0.2% to 0.3% of potassium dihydrogen phosphate should be sprayed for 2 to 3 times after emergence to enhance the disease resistance.
3, appropriate sowing to increase resistance. Bitter gourd thermophilic, the temperature is higher than 10 °C to normal fertility, so the sowing date should not be too early, open field cultivation, the north in early April sowing in the shed indoors, seedling 20 to 30 days.
4, pharmaceutical control. When necessary, it can be sprayed with 69% ank manganese water dispersible granules or wettable powders 1000-1200 times, or more than 80% Zn (Green Hunter No. 2) wettable powder 600-800 times, or 95% Greenhenge No. 1 boutique 4000 times liquid.
Interventional Accessories,Introducer Sheath Kit,Hydrophilic introducer sheath,PTFE coated guide wire,Y-Valve set
Anesthesia Medical Co., Ltd. , https://www.medicaldiverse.com