论文部分内容阅读
在棉花栽培中病害种类多,防治是一个难度较大的问题,主要病害有立枯病、炭疽病、猝倒病和根腐病等。棉花苗期发病主要原因是种子、土壤带菌,一旦遇到合适发病的环境和气候条件,苗期病害就会在苗床及移栽初期大量发生,危害棉苗的正常生长,一般年份苗病的发病率为30%~50%左右,死苗率为3%~6%,严重年份病苗发病率高达80%以上,苗期感病成为移栽缺苗或移栽大田后接二连三出现死苗的主要原因。近十多年来随着转基因抗虫棉的推广,棉花苗病有逐年加重的趋势,直接影响棉花的一播全苗和壮发早苗。因
There are many kinds of diseases in cotton cultivation, prevention and control is a difficult problem, the main diseases are blight, anthracnose, damping off and root rot. Cotton seedling incidence is mainly due to seed, soil-borne, in the event of a suitable incidence of environmental and climatic conditions, seedling disease will occur in large numbers during seedling and transplanting, endanger the normal growth of cotton seedlings, the general year of the incidence of Miao disease The rate is about 30% ~ 50%, the rate of dead seedlings is 3% ~ 6%, the incidence of the disease is as high as 80% in severe years, and the seedling susceptibility becomes the main one after another the reason. In the recent ten years, with the popularization of transgenic insect-resistant cotton, cotton seedling disease has a tendency of increasing year by year, which has a direct impact on the seedling emergence and seedling emergence of cotton. because