柑橘溃疡病田间消长规律及药剂防治技术

DYNAMIC REGULATION IN FIELD AND THE CHEMICAL CONTROL TECHNIQUES OF CITRUS CANKER

多年田间系统观察表明 ,柑橘溃疡病的消长 ,在春梢期 ,主要影响因子为气温。 4月下旬平均气温 2 0℃持续 1 0～ 1 5d ,田间始病 ;平均气温 2 5℃连续 3d ,田间进入病情激增期。在夏、秋梢期 ,主要影响因子为湿度和降雨。相对湿度低于 70 % ,不利于发病 ;持续阴雨或短时大雨极有利于流行。溃疡病的药剂防治应掌握在春梢展叶后 7d用药 ,夏、秋梢则萌芽后即用药。药剂品种以可杀得和百菌清最理想 ,喷药次数以 3次为好。

The systemic observation in the field for many years showed that temperature was the main factor affecting the dynamics of citrus canker in the stage of spring sprouting. The disease appeared when the average temperature of the last 10 days of April was 20℃ for 10 to 15 days. It developed rapidly when the average temperature was up to 25℃ for 3 days. Humidity and precipitation were the main factor affecting the disease in the stage of summer and fall sprouting. It was not favorable for the development of the disease if the relative humidity was lower than 70%. Long period of overcast and rainy or short time rainstorm was conducive to the epidemic of the disease. Apply chemicals such as copper hydroxide and chlorothalonil three times after 7 days of the leaves fully development in spring sprouting stage and just after germination of heads and leaves in summer and fall sprouting stages can control the disease effectively.