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向日葵是我区的主要油料作物之一,1990年种植44.1万亩,占油料作物播种面积的40％左右。近几年来,向日葵病害发生种类多,危害重。生长期发生的有霜霉病、菌核病、黑斑病、褐斑病、叶斑病、锈病等。特别是霜霉病,它是世界公认的一种危险性病害,也是全国的植物检疫对象。我区1986年首次发现该病,当年发生范围只是个别乡村,平均发病株率不到1％。1987年在忻州市、繁峙县调查6个乡、6个村、7块地、3187株,其中有病株33株,发病率2.29％;1988年在
Sunflower is one of the main oil crops in our district. In 1990, it was planted with 441,000 mu, accounting for about 40% of the sown area of oil-bearing crops. In recent years, many types of sunflower diseases, endanger heavy. Downy mildew, sclerotinia, black spot, brown spot, leaf spot, rust and so on. In particular, downy mildew, which is recognized as a dangerous disease in the world, is also a national plant quarantine object. The district first discovered the disease in 1986, when it occurred only in a few villages, with an average rate of less than 1% of the plants. 1987 in Xinzhou City, Fanshi County survey 6 townships, 6 villages, 7 plots, 3187 strains, of which 33 strains of diseased, the incidence of 2.29%; in 1988 in