Occurrence of sugarcane pokkah boeng in sugarcane planting areas in cities of Liuzhou and Laibin, Guangxi in 2016 and variety resistance analysis

ObjectiveThe present study investigated occurrence of sugarcane pokkah boeng in Liuzhou and Laibin of Guangxi and varieties resistance, in order to provide scientific reference for sugarcane variety distribution and disease con-trol. MethodA survey was conducted in six counties of Liuzhou and Laibin with methods of fixed-point and random selection. Pokkah boeng occurrence at initial stage was investgated. According to disease degree , pokkah boeng resistance of sugarcane varieties in field was comprehensively evaluated combing disease resistance standard and clustering analysis. Regional difference of sugarcane pokkah boeng occurrence was analyzed as well. ResultIncidence of sugarcane pokkah boeng in Liuzhou and Laibin was 0-6.11%. incidence of new-planting was 0.34%-1.87%and that of ratoon was 0-6.11%. Ratoons were more susceptible than new-plantings except for variety Liucheng 05-136. Disease incidence was the highest on variety Yuetang 93-159 in Xingbin district of Laibin city, and followed by variety Yuetang 00-236 in Wuxuan county of Laibin city. Based on the resistance performance of ratoon and new-planting in different areas, three varieties Liucheng 03-1137, ROC16 and GT40 were identified as high resistance, and the rest six varieties were identified as resistance. In terms of county sugarcane planting areas, there was obvious difference in disease incidence in the six investigated counties (districts). The incidence in Wuxuan county was the highest(2.85%) and that in Rong'an county was the lowest(1.52%). In terms of city sugarcane planting areas, there was no obvious difference in pokkah boeng incidence in the two areas (Li-uzhou and Laibin)(P>0.05). The incidence in Liuzhou(1.93%) was lower than that in Laibin(2.39%). ConclusionAt present, pokkah boeng is not a serious threat to sugarcane planting in Liuzhou and Laibin. There is no obvious difference in disease incidence regarding Liuzhou and Laibin, but there is obvious difference regarding county sugarcane planting areas. Sugarcane variety has a certain genetic stability concerning pokkah boeng disease resistance , but regional climate and eco-logical environment conditions are key factors affecting the occurrence and development of sugarcane pokkah boeng.