乐亭县是一个蔬菜生产大县,春棚甜瓜年种植面积在7万亩以上,随着种植规模的扩大、种植年限的延长,重茬面积加大,各种土传病害呈加重发生趋势,尤其是甜瓜蔓枯病发生比较严重,一般病株率10-15%,严重的可达30%以上,对甜瓜的产量和质量构成了严重威胁。 Laoting County is a vegetable production county, Spring Squash melon planting area in more than 70000 acres, with the expansion of planting, planting years, crop area increases, all kinds of soil-borne diseases is increasing trend, especially Melon is more serious occurrence of ginkgo blight, the general plant strain rate of 10-15%, severe up to 30% or more, the melon production and quality pose a serious threat.