不同药剂对山西省苹果树腐烂病优势种群的室内毒力及田间防效测定

Toxicity to Dominant Species and Field Efficacy of Several Fungicides on Apple Tree Canker in Shanxi Province

通过菌丝生长速率法检测了吡唑醚菌酯、辛菌胺、甲基硫菌灵3种药剂对山西省苹果树腐烂病优势种群Valsa mali var．mali的室内毒力，并应用整树喷淋法连续2a测定了4种常用药剂对苹果树腐烂病的田间防效。室内毒力测定结果表明，吡唑醚菌酯对苹果树腐烂病菌生长的抑制作用最佳，甲基硫菌灵次之，辛菌胺抑制作用最低，3种药剂的Ec。平均值均低于5．0μg／mL；田间防效测定结果表明，3％辛菌胺醋酸盐水剂30-40倍液和25％吡唑醚菌酯乳油1000～1500倍液的2个高浓度处理对苹果树腐烂病病疤复发和新病疤产生的防效均在75％以上，可作为喷淋法防治苹果树腐烂病的选择药剂及适用浓度。

The toxicity of 3 fungicides to Valsa mali var. mali, including pyraclostrobin, xinjunan and thiophanate-methyl, was tested by mycelium growth rate method. The field efficacy of the 4 fungicides were detected also by spraying to the whole tree after apple tree bark was scraped. The toxicity test results indicated that pyraclostrobin had the best inhibition effect, thiophanate-methyl took secend place, xinjunan was the lowest one, but their average EC50 was lower than 5.0 μg/mL. The results of field efficacy showed that the control effect of pyraclostrobin 25% EC 1 000-1 500 times and xinjunan 3% AS 30-40 times were more than 75% on the recurrence of apple tree canker scar and new scar production, and the two fungicides with the tested concentration could be selected to control apple tree canker by spraying to the whole tree.