杀菌剂和杀虫剂使用对玉米病虫害防治及效益分析

玉米病虫害是影响玉米产量和品质的重要因素。本研究选择2种杀虫剂(40%氯虫苯甲酰胺·噻虫嗪WG和100 g/L顺式氯氰菊酯EC)和4种杀菌剂(18.7%丙环唑·嘧菌酯SE、250 g/L吡唑醚菌酯EC、125 g/L氟环唑SE和17%吡唑醚菌酯·氟环唑SE),通过单独或组合在玉米心叶期(V12)一次性施药,并在药后7 d接种玉米弯孢菌,随后对各处理的防治效果和经济效益进行比较分析。基于施药成本、施药后的增产效益和玉米价格,采用贝叶斯推断统计方法计算净利润的概率。在盈利平衡点(纯利润为0),通过施药获得净利润的概率变幅在0.328～0.998之间;如果要获得1 500元/hm~2的净利润,各施药处理概率的变幅为0.024～0.993,其中40%氯虫苯甲酰胺·噻虫嗪WG+18.7%丙环唑·嘧菌酯SE处理的盈利概率最高(0.986～0.993),其次18.7%丙环唑·嘧菌酯SE和40%氯虫苯甲酰胺·噻虫嗪WG+17%吡唑醚菌酯·氟环唑SE处理的盈利概率也超过0.947。本研究表明40%氯虫苯甲酰胺·噻虫嗪WG+18.7%丙环唑·嘧菌酯SE是防治当地玉米病虫害理想的杀虫剂杀菌剂施药组合。

Effects and profitability of insecticide and fungicide applications for pest management in maize

Maize disease and insect pests have a negative impact on yield and quality of maize. In this study, two insecticides (chlorantraniliprole·thiamethoxam 40% WG and alpha-cypermethrin 100 g/L EC) and four fungicides (propiconazole·azoxystrobin 18.7% SE, pyraclostrobin 250 g/L EC, epoxiconazole 125 g/L SE, and pyraclostrobin·epoxiconazole 17% SE) were applied alone or in insecticide-fungicide combinations to maize plants at growth stage V12, and then inoculated the pathogen Curvularia lunata seven days after spray. Their control effects and influence on yields and economic benefits were evaluated. Based on the mean yields and standard deviations for treated and untreated plots, the price of grain, and the costs of the pesticide applications, the probability of achieving a positive net return after pesticide application was calculated using Bayesian inference methods. Probabilities for achieving a net return of 0 (break-even point) ranged from 0.328 to 0.988 for ten pesticide applications. Under a net return of 1 500.0 yuan/hm2, probability of profit ranged from 0.024 to 0.993. The probabilities of profit by propiconazole·azoxystrobin 18.7% SE, chlorantraniliprole·thiamethoxam 40% WG+propiconazole·azoxystrobin 18.7% SE, and chlorantraniliprole·thiamethoxam 40% WG+pyraclostrobin·epoxiconazole 17% SE were all more than 0.947. Among them, the highest probabilities of profit occurred in application ofchlorantraniliprole·thiamethoxam 40% WG+propiconazole·azoxystrobin 18.7% SE, which was the effective insecticide-fungicide combination for maize disease and insect pests control.