１背景土传病害一直是蔬菜病虫害防治工作中的一个难点。近年来，由于保护地高密集型连作，有利于土传病害病原和地下害虫虫源的积累，其为害呈逐年上升的趋势，已经成为保护地蔬菜高产优质的一个重要制约因素。１９９９年，我们通过对辽宁、黑龙江、河北、河南、天津和江西等 1 Background Soil-borne diseases have always been a difficult point in the prevention and control of vegetable pests and diseases. In recent years, due to the high concentration of protected continuous cropping is conducive to the accumulation of soil-borne diseases and insect pest origin, the harm has been increasing year by year, and has become an important factor restricting the high yield and quality of protected vegetables. In 1999, we passed Liaoning, Heilongjiang, Hebei, Henan, Tianjin and Jiangxi