辣椒疫病发生规律及防治研究

STUDY ON THE OCGURENGE OF PHYTOPHTHORA BLIGHT PEPPER AND ITS INTEGRATED CONTROL

辣椒疫病(Phytophthora capsici Leonina)近年逐渐加重,成为制约辣椒丰产的主要病害.重庆从五月中旬开始发病,五月下旬和六月下旬为高峰期,自贡五月中旬发病,六～七月为高峰期.同期气温20～30℃,相对湿度70%以上,发病后5～10天连绵阴雨有利于病害流行,五月下旬到六月上旬旬降水量与病害流行是正相关(r=0.8951).不同辣辣品种对疫病反应有差异,以朝天椒、七星椒较耐病.田间和室内试验表明:杀毒矾M8、瑞毒铜500～700倍喷雾4～5次防效81.6～86.9%,能有效地控制病害流行.防治上宜采用轮作,选用抗耐病良种,深沟、高畦、窄厢栽培以及配方施肥,适时施药等以及农艺措施为主体的综合防治措施.

In recent years phytophthora blight of pepper (Phytophthora capsici Leon) was a main disease to limit the yield and the epidemic became serious year by year. The disease occured from middle of May in Zigong and Chongqing. The occurence top stages were in the late May and the late June in Chongqing. But in Zigong the occurence top stage was from June to July. In these periods the temperature was 20-30°C and the relative humidity was more than 70%. Overcast and rainy favoured the epidemic of disease within five to ten days after the disease occured. From the late May to early June, rainfall was pasitive correlation with the epidemic of the disease (r=0.8951) . There were different reactions to Phytophthora capsici Leon among the different varieties. Chao Tian Jiao and Qi Xing Jiao were more tolerant. The effect of nine chemicals were tested in the laboratory and the fields, the effect was 81.6-86.9% by spraying Sandofan Mg and Rei Du Tong 1:500-700 for 4-5 times. It can control the epidemic of the disease effectively. The integrated control practice could control the diease as adopting crop relation, resistant-tolerant varieties, deep trench-high bed-paddy culture, rational manuring and spraying chemicals.