戊唑醇与嘧菌酯复配对稻瘟病和水稻纹枯病的联合毒力及田间防效

为了筛选防治稻瘟病和水稻纹枯病的高效药剂,采用菌丝生长抑制法测定戊唑醇、嘧菌酯单剂及其5种配比对稻瘟病菌和水稻纹枯病菌的毒力,通过田间药效试验评价增效剂的田间防效。室内毒力测定结果表明:戊唑醇与嘧菌酯质量比2:1时,对水稻稻瘟病菌和水稻纹枯病菌的生长抑制具有增效作用,增效系数(SR)分别为1.5777、1.5941。田间试验结果表明:戊唑醇与嘧菌酯复配质量比2:1使用剂量90～135 g a.i./hm²时,对稻瘟病防效达76.68%～91.12%,对水稻纹枯病防效达81.28%～90.32%,与单剂和对照药剂相比防治效果相当或更好,并且用药量更低。本研究结果表明,戊唑醇与嘧菌酯质量比2:1复配用于防治水稻稻瘟病和水稻纹枯病,可以达到农药减量增效的目的。

Mixtures of Tebuconazole and Azoxystrobin: Indoor Toxicity and Field Control Effects on Rice Blast and Rice Sheath Blight

To select efficient fungicides to control rice blast and rice sheath blight, the mycelium growth inhibitory method was used to determine the virulence of tebuconazole and azoxystrobin and their 5 matching ratios to Pyricularia oryzae and Rhizoctonia solani, a field test was also used to determine the control efficacy of the synergist. The results of indoor toxicity determination showed that when the ratio of tebuconazole to azoxystrobin was 2:1, it had synergistic effect on Pyricularia oryzae and Rhizoctonia solani, and the synergistic ratio was 1.5777 and 1.5941, respectively. The results of field tests showed that the control efficacy against rice blast and rice sheath blight was 76.68%-91.12% and 81.28%-90.32% respectively when the ratio of tebuconazole and azoxystrobin was 2:1 at the dosage of 90-135 g a.i./hm². The synergist had equivalent or better control efficacy and the dosage was lower compared with single and control fungicides. The results indicate that the ratio of tebuconazole and azoxystrobin 2:1 as an effective agent for controlling rice blast and rice sheath blight could reduce the use of fungicides application and increase efficiency.