Precision chemical control strategy for Spodoptera frugiperda on fresh maize

Author of the article:SU Xian-Yan1** HU Fei1 CHEN Yong-Tian2 HAN Hai-Liang3 NIE Xi-Man4 GU Kai-Xin1 SHI Xue-Yan5 W

Author's Workplace：1.Institute of Plant Protection and Agro-products Safety, Anhui Academy of Agricultural Sciences, Hefei 230031, China; 2. Wuwei Station of Plant Protection, Anhui Province, Wuwei 238300, China; 3. Institute of Maize and Featured Upland Crops, Zhejiang Academy of Agricultural Science, Dongyang 322100, China; 4. Hefei Agricultural Economic and Technical Service Management Station, Hefei 230041, China; 5. College of Plant Protection, China Agricultural University, Beijing 100083, China; 6. Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100081, China

Key Words：fresh maize; Spodoptera frugiperda; pesticide application period; precision pesticides control; control effect

Abstract：[Aim]  To develop an efficient and precise method of chemical control to control Spodoptera frugiperda in fresh maize crops, with the aim of reducing the frequency of chemical applications while improving control efficacy. [Methods]  The effectiveness of pesticide applications at different maize growth stages, including the pre-transplanting, seedling stage, late whorl stage, and tasseling stage, were measured and compared to determine the optimal chemical control strategy for S. frugiperda in fresh maize crops. [Results]  The efficacy of applying "sending-off" pesticide to fresh maize before transplanting was 60.90% ± 5.08% 14 days after application, remained at 60.02% ± 4.79 % after 23 days, then decreased to 16.04% ± 23.92% after 30 days. Combining an application of "sending-off" pesticide with one foliar spray at the seedling stage, achieved efficacies at 3, 7, and 14 days after application of 98.75% ± 2.80%, 95.14% ± 8.13%, respectively, and 79.20% ± 8.43%, after the final application, then declined to 22.00% ± 5.81% at the late whorl stage. A single application of granules at the whorl stage, achieved control efficacies at 3 and 7 days after application of 70.06% ± 2.47% and 34.93% ± 11.83%, respectively. A single spray at the tasseling stage, achieved control efficacy during the ear stage of from 71.90%± 27.06% to 85.83% ± 14.91%. No damaged ears were observed at harvest, and the proportion of marketable ears increased by 11.59% ± 6.93%. [Conclusion]  One pre-transplanting application of pre-planting pesticide, combined with one spray of highly effective, low-toxicity chemical pesticides at the seedling, late whorl, and tasseling stages, can effectively control S. frugiperda in fresh maize crops. Of these pesticide regimes, the pre-transplant pesticide application and the tasseling-stage application play key roles in managing S. frugiperda in summer-sown fresh maize.