Greenhouse Production Of Non-Polluted Vegetables In Zhejiang Province And Application Of Soil Solarization In Pest Control

Problems and possible solutions of vegetable production and greenhouse production of vegetable are studied through analysis of the current status in Zhejiang Province. Vegetable production has been developed quickly during last 20 years, many problems are now being main restriction factors in vegetable production in Zhejiang Province, among which product safety is a key factor. Insect pests and diseases on vegetable crops have been increased both in species and in occurrence frequency. Over-application of chemical pesticides for pest control has resulted in high level of pesticide-resistance in insect pests and pathogens, which in turn leads to significant increases in pest control. On the other hand, some secondary insect pests and diseases are now becoming new problems in vegetable production and efficient means for control of these pests and diseases are still lacking in practice. In the recent years, with development and extension of greenhouse and off-season vegetable production, ecological environments in vegetable production have been changed greatly. Heavy occurrence of insect pests and diseases results in over-use of pesticides in vegetable production, which greatly increases risk of pesticide residues in vegetable product.There are similar problems in greenhouse production of vegetable industry in Zhejiang Province. Greenhouse environments with high humidity, constant temperature and heavy continuous cropping provide favor conditions for growth and evolution of insect pest and pathogens, and thus result in high frequency of occurrence of insect pests and diseases in greenhouse vegetable production. Control of insect pests and diseases, especially soil-borne root diseases, is among the most important restriction factors in greenhouse vegetable production. In greenhouse vegetable production, use of resistant cultivars and healthy seedlings should be considered as first step in pest control. Meanwhile, application of combined different means with theory of integrated pest management is a reasonable way for pest controls.Soil solarization takes use of solar energy to kill harmful microbes in soil and thus protect crop plants from pathogen infection. Soil solarization has become one of the most important novel strategies for pest control in production of non-polluted vegetables. Studies have shown that soil solarization can efficiently kill pathogens, insect pests and weed seeds in soil and thus provide a safe, non-chemical, and environment-friendly and low-cost mean for pest and weed control. Application of soil solarization in greenhouse vegetable production can ultimately reduce input of chemical pesticides and therefore efficiently reduce pesticide residues in vegetable products. However, soil solarization needs a long time period and its efficiency is often affected by various factors, including environmental temperature, solar radiation, sunlight time and soil temperature.