Daylight greenhouse vegetable cultivation is the majority of farmers and friends of the important way to get rich. But in recent years, solarium veg in a variety of pests and diseases occur frequently, seriously affecting the yield of vegetables and farmers' economic income.
Early winter greenhouse, tomato often a large number of dead seedlings, mainly caused by wilt, root rot.
Prevention and control of wilt disease
Symptoms: slow growth in the flowering and fruiting period of the plant, the lower leaves turn yellow, gradually upward. The leaves wilt at noon and recover at night, and after several days of repetition, the whole plant wilts and dies.
Causes: The disease is transmitted by fungi. The fungus can survive in the soil for many years, and it occurs seriously in continuous cropping.
Prevention and control methods:
(1) varieties. Select varieties that are resistant to wilt.
(2) Crop rotation. Implement crop rotation with non-fruit crops for more than 3-5 years. Seedbeds should be transferred to a different place or changed to new soil in 2-3 years.
(3) Improve soil and apply no-deep-tillage soil conditioner. In heavy disease areas or heavy-crop land, combine with land preparation and apply 200-1500kg of cooked lime powder per hectare to inhibit the development of the disease. Apply no-deep ploughing soil conditioner to make the deep soil loose and permeable, and reduce the concentration of pathogens in the upper layer of the soil through rain or watering, so as to reduce the onset of disease.
(4) Seeds. Seed disinfection is carried out before seedling germination, and the commonly used methods include: soaking seeds in warm broth; dry heat treatment, in which dry seeds are placed in a constant temperature of 70℃-75℃ for 5-7 days.
(5) Soil disinfection. In the protected area, in the summer free time, after tilling the ground, ridge, cover the ground film, and then close the greenhouse, use the sunlight to raise the temperature in the protected area, so that the ground temperature of more than 20 cm reaches more than 45 ° C, which can eliminate most of the wilt germs.
(6) Pharmaceutical control. At the early stage of the disease, 50% carbendazim wettable powder 500 times liquid; or 50% metribuzin 400 times liquid; or 10% Shuangxin Ⅱ water 200-300 times liquid; or 100 times liquid of Nong's resistance to 120; or 48% Ruiku Mould water 800 times liquid, 0.25 kg of liquid per plant irrigation root, every 10 days 1 time, 2-3 times in a row.
Control of root rot
Symptoms: Slow growth during flowering and fruiting, lower leaves turn yellow and gradually develop upwards. Leaves wilt at noon, recover at night, repeated for several days, the whole plant withered and died.
Causes: The disease is transmitted by fungi. The fungus can survive in the soil for many years, and it occurs seriously in continuous cropping.
Prevention and control methods: Seed disinfection: take seeds from disease-free plants, or disinfect the seeds by soaking them in warm water at 50℃ for 20 minutes. Seedbed disinfection: choose disease-free soil as seedbed, or use 50% diclofenac ammonium 200-400 times solution to water the seedbed soil. Use no-deep-tillage soil conditioner to improve the soil before sowing or after planting to make the deep soil loose and permeable, and reduce the concentration of pathogens in the upper layer of the soil through raining or watering drenching to alleviate the disease. Soil disinfection: In the protected area, during the summer free time, after the land is prepared and the ridge is raised, the ground is covered with mulch, and then the greenhouse is closed, so that the sunlight is used to raise the temperature in the protected area, so that the ground temperature above 20 cm reaches more than 45 ℃, which can eliminate most of the pathogens. Pharmaceutical control: before the onset of the disease with 65% zinc 500-600 times liquid; or 50% ammonium diclofenac 1000 times liquid spray, every 5-7 days 1 time, even spray 2-3 times to prevent. At the beginning of the disease, we can use 50% carbendazim wettable powder 500 times liquid; or 50% metribuzin 400 times liquid; or 10% double-effect Ling II water 200-300 times liquid; or agricultural resistance 120 100 times liquid; or 48% Ruiku mould water 800 times liquid, each plant irrigation root 0.25 kg of liquid, every 10 days 1 time, 2-3 times in a row.
