火龙果煤烟病发生动态及防治药剂筛选

Occurrence Dynamics and Control Agent Screening of Soot Disease of Pitaya

【目的】探究火龙果煤烟病发生动态并筛选防治药剂,为制定火龙果煤烟病有效防治策略提供参考依据。【方法】采用五点取样法,随机抽样调查2018-2019年火龙果植株不同发育时期嫩梢、花蕾、花萼及果实等部位的煤烟病发生情况,计算相应的病情指数,记录温、湿度数据,绘制植株各部位煤烟病发生动态曲线图;在发病较重的火龙果种植园开展5种药剂防治试验,筛选适宜防治火龙果煤烟病的药剂。【结果】火龙果嫩梢煤烟病病情高峰期发生于每年的4月下旬;花蕾煤烟病病情高峰期发生在每年的4月中旬、7月中旬和9月下旬;花萼煤烟病病情高峰期发生在每年的7月下旬、8月中旬和9月下旬;幼果煤烟病病情高峰期发生在每年的5月中旬、7月下旬和9月下旬;膨大期果实煤烟病病情高峰期发生在每年的5月中旬、8月中旬和10月中旬;成熟期果实煤烟病病情高峰期发生在每年的7月下旬、9月中旬和10月中旬。田间防治试验结果表明,40%嘧霉胺悬浮剂750倍液、500.0 g/L异菌脲悬浮剂750倍液、440.0 g/L甲霜灵·百菌清悬浮剂750倍液、75%百菌清可湿性粉剂600倍液和45%代森铵水剂750倍液对火龙果煤烟病的防治效果均在70.00%以上。【结论】在广西崇左市和南宁市,每年4-10月各月的上旬是防治火龙果煤烟病的适宜时期,40%嘧霉胺悬浮剂750倍液、500.0 g/L异菌脲悬浮剂750倍液、440.0 g/L甲霜灵·百菌清悬浮剂750倍液对火龙果煤烟病的防效均在70.00%以上,可推荐在生产上交替使用。

【Objective】To explore the occurrence dynamics of pitaya soot disease and screen the control agents,and to provide a reference for the development of effective control strategies for pitaya soot disease.【Method】The five sampling points method was used and random sampling survey in 2018-2019 pitaya plant in different developmental stages period was conducted on tender tip,the bud,calyx,and expands fruit,fruit maturation and the parts of the soot disease occurrence,calculated the corresponding disease index,and recorded the temperature and humidity data,drew each part of the 2018-2019 pitaya plant soot disease occurrence dynamic graph.In order to screen out the suitable insecticides for the prevention and control of pitaya soot disease,five kinds of insecticides were carried out in the serious pitaya planting zone.【Result】The peak of soot disease on the young shoot of pitaya occurred in late April every year.The peak of bud soot disease occurred in the middle of April,the middle of July and the end of September.The peak of calyx soot disease occurred in late July,mid-August and late September every year.The peak of young fruit soot disease occurred in the middle of May,late July and late September.The peak of soot disease occurred in the middle of May,the middle of August and the middle of October.The peak of soot disease in mature fruits occurred in late July,mid-September and mid-October.The results of field control experiments showed that the control effects of 40%pyrimethanil suspension 750 times,500.0 g/L isobarbazone suspension 750 times,440.0 g/L metharazone·chlorothalonil suspension 750 times,75%chlorothalonil wettable powder 600 times and 45%diazonium water 750 times were above 70.00%.【Conclusion】In Chongzuo and Nanning in Guangxi,from April to October in each year,early period in month is suitable for prevention and control of pitaya soot disease period,after repeated experiments,40%pyrimethanil suspension 750 times,500.0 g/L isobarbazone suspension 750 times,440.0 g/L metharazone·chlorothalonil suspension 750 times liquids have over 70.00%control effect on pitaya soot disease.These three agents are recommended for use in manufacturing.