夏橙绿斑病病原鉴定及其化学防治

The pathogen identification of Citrus sinensis green spot disease and its chemical control

对重庆夏橙基地夏橙发生的绿斑病症状和病原藻形态进行了观察,并进行了病原藻分离及致病性测定。结果表明,该病是由绿藻门虚幻球藻属虚幻球藻Apatococcus lobatus所致。室内毒力测定表明,50%新灵(多菌灵+代森锰锌)WP、62.25%仙生(腈菌唑+代森锰锌)WP、10%世高WG、25%炭特灵WP与53.8%可杀得DF对病原藻的生长都具有一定的抑制作用,其EC50分别为2.3531、2.6234、9.3815、13.8816、28.9808mg/kg。田间小区试验结果表明,50%新灵WP600倍和62.25%仙生WP600倍液的防治效果较好,其次为10%世高WG1000倍和53.8%可杀得DF1000倍液,而25%炭特灵WP600倍液的防治效果较低。经方差分析,处理间存在显著差异。

In view of the prevalence of green spot disease in Citrus sinensis Osbeck base in Chongqing, its symptoms and the shapes of its pathogens were observed. The separation of its pathogens and the determination of its pathogenicity were also conducted. The results showed that Citrus sinensis green spot disease was a new disease caused by Apatococcus lobatus of Chlorophyta. Effective concentration （EC5o） of 50% carbendazim ＋ mancozeb WP, 62.25% myclobutanil ＋ mancozeb WP, 10% difenoconazole WG, 25% bromothalonil WP and 53.8% copper hydroxide DF to inhibit the growth of Apatococcus lobatus was 2. 3531,2. 6234, 9. 3815, 13. 8816 and 28. 9808 mg/kg by toxicity tests in the laboratory, respectively. The control effect of 600 times 50% carbendazim ＋ mancozeb WP, 600 times 62.25% myclobutanil ＋ mancozeb WP to the growth of Apatococcus lobatus by field tests was higher than that of 1000 times 10% difenoconazole WG, 1000 times 53.8% copper hydroxide DF and 600 times 25% bromothalonil WP. There was significant differences between treatments by Duncan＇s test.