唑菌酯及其混剂防治黄瓜靶斑病室内及田间药效试验

Lab and Field Efficacy of Mixtures Containing Pyraoxystrobin against Corynespora cassiicola

[目的]探索唑菌酯及其混剂防治黄瓜靶斑病的效果及剂量。[方法]采用菌丝生长速率法测定唑菌酯与苯醚甲环唑对靶斑病菌的联合毒力,验证20%唑菌酯SC及24%唑菌酯·苯醚甲环唑SC对黄瓜靶斑病的田间防效。[结果]唑菌酯与苯醚甲环唑对靶斑病菌的EC50值为（11.49±1.19）、（0.82±0.06）mg/L;唑菌酯与苯醚甲环唑1颐1、1颐2、1颐3三个配比有增效作用。[结论]靶斑病发病初期间隔7 d连续喷施2～3次20%唑菌酯SC或24%唑菌酯·苯醚甲环唑SC有较好防效;20%唑菌酯SC推荐剂量为150～300 g a.i./hm^2,而24%唑菌酯·苯醚甲环唑SC推荐剂量为360～540 g a.i./hm^2。

[Aims] This paper aims to explore control efficacy and dosage of pyraoxystrobin and its mixtures against cucumber target spot through indoor and field trials. [Methods] The tests were carried out by methods of mycelial growth rate and field trials to confirm the efficacy of mixture containing pyraoxystrobin. [Results] The results showed that the EC50 of pyraoxystrobin and difenoconazole to Corynespora cassiicola were（11.49±1.19） and（0.82 ±0.06） mg/L respectively. The synergic toxicity tests to C. cassiicola Wei showed that the SR of pyraoxystrobin with difenoconazole was partly more than 1.5 and the mixed preparations had synergistic effect. Field trails results showed that C. cassiicola can be controlled well by spraying pyraoxystrobin 20% SC and mixed pyraoxystrobin and difenoconazole 24% SC once leaf spot occurs at the concentration of 150-300 and 360-540 g a.i./ha respectively. [Conclusions] Pyraoxystrobin 20% SC,mixed pyraoxystrobin and difenoconazole 24% SC can be applied to control cucumber leaf spot in practical production.