Symptoms: In the October-December period of wintering greenhouse cultivation, the first and second ear fruits of the indefinitely growing variety expanded at noon on sunny days, especially at noon on the first day of sunny days, and the upper leaves and growing points began to appear wilting and recover sooner or later. normal. No obvious lesions on the leaves are different from the disease. The disease continues to develop, spread and spread, and the entire shed is sluggish. Serious whole plant death. No abnormalities were found in the roots of the diseased plants. Only some of the lateral roots were yellow-brown and distinct from root rot. As the disease progresses, all roots turn yellow and rot. There is a hollow phenomenon in the upper part of the stem, and there is no abnormal phenomenon in the middle and lower parts, which is different from the wilt disease and bacterial wilt. The occurrence of the disease was not related to watering the head and head, and no infection occurred. Incidence of conditions and regularity 1 The incidence of land masses that continued for more than three years was severe. 2 The soil is heavy and heavy, especially in the former rice field. 3 When using a rotary plough to turn the floor and the depth is less than 10 centimeters, the overly compacted land on the bottom of the plough has serious disease. 4 There are too many nitrogen fertilizers at the seedling stage, the seedlings are too long, and the disease is severe when the seedlings grow. 5 The colonization density is high, nitrogen fertilizer is too much, stems and leaves grow too vigorously, and when the leaf area is too large, the incidence is serious. 6 After planting, the cultivator was too deep and the roots were severely damaged; whitefly and Other insect pests were serious; long-term and sunny days; excessive turbulence and other factors could cause severe disease. Prevention method 1 rotation: Do not repeat for more than 3 years. 2 Deep turning: Before the cultivation, the soil turned over 25 cm deep. 3 application of plough-free soil conditioner: 200 grams per acre, plus 100 kg of water sprayed on the ground, can make loose 50-100 cm of soil permeability, reduce the incidence of the disease. 4 appropriate sowing and planting, avoiding the high temperature period. 5 seedlings to prevent leggy, seedling age to 7-8 leaves, the first flower bud is now appropriate. 6 The density of colonization is appropriate and not too dense. 7 When cultivating, attention should be paid to avoiding injury and rooting. Insect pests and diseases should be promptly prevented and 10,000-fold liquid of sapogenin-Shuofeng 481 should be used once to promote photosynthesis and produce more nutrients to ensure root growth and development. 8 In the early winter greenhouses, greenhouses are mainly used for top winds, and less ground wind is used. When going out of the air, from small to large, step by step. 9 Topdressing should be combined with nitrogen, phosphorus and potassium. Avoid using more nitrogen fertilizer. 10 If physiological wilting occurs, cover grasshoppers at low noon for strong sunlight and reduce light; timely topping, inhibit growth, and reduce the consumption of water and fertilizer in the shoot; and spray 0.2% potassium dihydrogen phosphate once. The above measures can alleviate the occurrence of wilting.
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