Systematic measurements to damage and yieldloss due to yellow stem borer (YSB) weremade in the single crop and double crop areasof Hangzhou, Jiaxing, and Huzhou cities,northern Zhejiang Province in 1987-1994. YSBeggma...Systematic measurements to damage and yieldloss due to yellow stem borer (YSB) weremade in the single crop and double crop areasof Hangzhou, Jiaxing, and Huzhou cities,northern Zhejiang Province in 1987-1994. YSBeggmasses were released on rice plants at 0,1, 3, 6, 9, 12 eggmasses per plot (equal to0, 495, 1 500, 3 000, 4 500, and 6 000eggmasses per hectare) from tillering to head-ing. The plot size was 20 m~2. There were 3replications randomly lined. The results in 6locations during 4-6 years of 1987-1994showed that the grain losses caused by eacheggmass at tillering stage was 59.11±2.99 g,elongating 63.18±1.51 g, and heading 74.58展开更多
Background The evolution of Bacillus thuringiensis(Bt)resistance in cotton pink bollworm(Pectinophora gossypiella)has renewed reliance on insecticides,making precise application timing vital due to the pest’s interna...Background The evolution of Bacillus thuringiensis(Bt)resistance in cotton pink bollworm(Pectinophora gossypiella)has renewed reliance on insecticides,making precise application timing vital due to the pest’s internal feeding habit.This study refines the economic injury level(EIL)for pink bollworm using pest-infestation gradients and yield loss-damage functions.The EILs were estimated and converted to action thresholds(75%of EIL).The sensitivity to control costs,cotton prices,and control efficacy was considered in calculating the EIL.Additionally,the relationship between national pheromone-trap data(2015-2023)and green boll infestation was examined.Results Based on the average cotton prices,optimum control cost,and desirable control efficacy,EILs ranged from 7.1%to 8.6%of boll infestation,with corresponding action thresholds of 5.3%and 6.4%for<120 days after sowing(DAS)and>120 DAS crop stages,respectively.Control efficacy emerged as the most influential factor on EILs.Corresponding pheromone trap catch-based action thresholds were revised to 4.5 and 5.7 moths per trap per night,lower than the existing 8.0 moths per trap per night tied to a 10%boll infestation threshold.Validation using multi-location data supported refined estimates.Conclusions The study demonstrates that maintaining high control efficacy is central to keeping EILs low and enabling timely intervention against pink bollworm.Effective control reduces the pest’s damage potential,lowers the onset of economic loss,and supports earlier,more reliable ET-based actions.These results collectively ensure better suppression of pests and promote economically efficient,agronomically robust pest management.展开更多
文摘Systematic measurements to damage and yieldloss due to yellow stem borer (YSB) weremade in the single crop and double crop areasof Hangzhou, Jiaxing, and Huzhou cities,northern Zhejiang Province in 1987-1994. YSBeggmasses were released on rice plants at 0,1, 3, 6, 9, 12 eggmasses per plot (equal to0, 495, 1 500, 3 000, 4 500, and 6 000eggmasses per hectare) from tillering to head-ing. The plot size was 20 m~2. There were 3replications randomly lined. The results in 6locations during 4-6 years of 1987-1994showed that the grain losses caused by eacheggmass at tillering stage was 59.11±2.99 g,elongating 63.18±1.51 g, and heading 74.58
基金funded by the Indian Council of Agricultural Research(ICAR),Department of Agricultural Research and Education,Government of India to ICAR-Central Institute for Cotton Research(ICAR-CICR),Nagpur,Maharashtra,for the in-house research project titled“Revisiting the ETLs and yield loss assessment due to pink bollworm and boll rot in cotton”(Institute project code:IXX15662).
文摘Background The evolution of Bacillus thuringiensis(Bt)resistance in cotton pink bollworm(Pectinophora gossypiella)has renewed reliance on insecticides,making precise application timing vital due to the pest’s internal feeding habit.This study refines the economic injury level(EIL)for pink bollworm using pest-infestation gradients and yield loss-damage functions.The EILs were estimated and converted to action thresholds(75%of EIL).The sensitivity to control costs,cotton prices,and control efficacy was considered in calculating the EIL.Additionally,the relationship between national pheromone-trap data(2015-2023)and green boll infestation was examined.Results Based on the average cotton prices,optimum control cost,and desirable control efficacy,EILs ranged from 7.1%to 8.6%of boll infestation,with corresponding action thresholds of 5.3%and 6.4%for<120 days after sowing(DAS)and>120 DAS crop stages,respectively.Control efficacy emerged as the most influential factor on EILs.Corresponding pheromone trap catch-based action thresholds were revised to 4.5 and 5.7 moths per trap per night,lower than the existing 8.0 moths per trap per night tied to a 10%boll infestation threshold.Validation using multi-location data supported refined estimates.Conclusions The study demonstrates that maintaining high control efficacy is central to keeping EILs low and enabling timely intervention against pink bollworm.Effective control reduces the pest’s damage potential,lowers the onset of economic loss,and supports earlier,more reliable ET-based actions.These results collectively ensure better suppression of pests and promote economically efficient,agronomically robust pest management.
