制种玉米黑束病在不同土壤生态环境下发病规律的研究

在甘肃张掖大规模制种过程,采用人工调控土壤生态环境和田间调查方法,针对不同土体温度、湿度、酸碱度、养分含量,研究了菌丝体的生长状况和对寄主侵染的规律,提出了抗病品种为主的栽培措施以外的以调控土壤环境为主的防治方法。结果表明:致病菌枝顶头孢霉Acrrmonium strictum W.Gams在土壤pH7.0-8.0时生长迅速;生长适温为28～32℃,较菌丝体在培养基上的适温高;当绝对含水量在10%或20%时生长迅速;肥力因子N、K、P素对该病的影响较大,养分有效N素含量高、有效P素含量低、有效K含量不足发病重;病菌对幼苗的侵染也具明显的规律性,高温高湿有利于病菌对幼苗的侵染,病情指数增高,感病品种较抗病品种病情指数低。

Effect of Different Edaphic Factors on Occurrence of Black Bundle Disease of Maize

By means of manpower control and the sample investigation on cosmically seeding preparation,the effect of different temperature,humidity,pH and nutrient condition on occurrence of the black bundle disease of maize were studied. Relevant regulation were tested on the growth of pathogen and invading on host. The result showed that the mycelia of Acremonium strictum W.Gams grew well in pH 7-8, and proper temperature was 28-32℃ which is higher than the culture medium. In addition, 10 or 20% of absolute moisture was better than the others. The combination of high available nitrogen low available phosphorus and low available potassium could cause the disease occurring severly. The pathogen invasion was easily found in high temperature and humidity.