2020年广西象州县柑橘木虱爆发的原因分析及柑橘黄龙病菌检测

Cause Analysis of Diaphorina citri Outbreak in Xiangzhou County of Guangxi in 2020 and Detection of Candidatus Liberibacter asiaticus

田间调查发现,2020年广西象州县百丈乡砂糖橘上柑橘木虱的发生有2个高峰期,第1高峰期在夏梢嫩梢期,最高虫口密度为1330头/百梢;第2高峰期在秋梢嫩梢期,最高虫口密度为1050头/百梢。定期喷施化学药剂不能显著降低柑橘木虱的虫口密度。2020年柑橘木虱的大发生与2019年暖冬、2020年暖春及少雨有关。在3个乡镇的9个砂糖橘果园中均有柑橘黄龙病菌阳性样品,其中失管果园的阳性率最高达到90%,但3个黄皮果园的样品均呈阴性。可见,砂糖橘生育期和气象条件是柑橘木虱爆发的重要因素,在田间存在砂糖橘黄龙病的情况下,应根据气象条件,加强柑橘木虱的发生预测与防治,减缓砂糖橘黄龙病的蔓延。

Field investigation showed that there were two occurrence peaks of Diaphorina citri on Citrus reticulata‘Shatangju’in Baizhang Township,Xiangzhou County,Guangxi Zhuang Autonomous Region in 2020.The first peak was at the tender summer shoots stage,with the highest population density of 1330 Diaphorina citri per hundred shoots;the second peak was at the tender autumn shoots stage,with the highest population density of 1050 Diaphorina citri per hundred shoots.Regular spraying of chemicals could not significantly reduce the population density of Diaphorina citri.The outbreak of Diaphorina citri in 2020 was related to warm winter in 2019,warm spring and less rain in 2020.The positive samples of Candidatus Liberibacter asiaticus were found in 9 Shatangju orchards in 3 towns,and the highest positive rate was up to 90%in orchards without management,but all samples from 3 orchards of Clausena lansium were negative.Growth period of Shatangju and meteorological conditions contributed to the outbreak of Diaphorina citri.Aiming at the Candidatus Liberibacter asiaticus in the field,the occurrence prediction and control strategy of Diaphorina citri should be strengthened according to the meteorological conditions to slow the spread of the disease.