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采用GPS和GIS定位、系统监测和普查等方法,首次明确了南充市稻瘟病的流行区划和精准勘界,探明了19年来稻瘟病始见期和始见地(初始侵染源)、流行高峰期和趋势等特点。明确了南充市水稻稻瘟病发生始见期与发生程度的关系,即始见期越早,重发可能性越大;稻瘟病在田间存在4个流行高峰期,其中第1个流行高峰期发生面积对当年病害流行起着决定作用,5月底的累计发生面积与年发生面积成正相关,相关系数为0.817 2。导致稻瘟病重发的内因是水稻品种抗稻瘟能力的降低或丧失、稻瘟病病菌致病力强的生理小种增加与更强致病力的小种出现;外因是温度适宜和阴雨寡照偏多。
The methods of GPS and GIS, system monitoring and census were used to identify the epidemic zonation and precise demarcation of rice blast in Nanchong for the first time. Period and trend and other characteristics. The relationship between the initial period and the occurrence degree of rice blast in Nanchong City was clarified, that is, the earlier the initial period was, the greater the possibility of re-transmission. The rice blast had 4 peak periods in the field, of which the first occurred at the peak period The area played a decisive role in the prevalence of the disease in the year. The cumulative area at the end of May was positively correlated with the annual area, with a correlation coefficient of 0.817 2. The internal factors that led to the relapse of rice blast were the reduction or loss of rice blast resistance, the increase of pathogenicity of races of rice blast and the emergence of races of stronger virulence. many.