Managing pests after 15 years of Bt cotton: Farmers' practices, performance and opinions in northern China

Our results indicated that farmers used chemicals somewhat intensively, carrying out 11 insecticide sprayings on average, involving an average of 2 pest target-oriented insecticide controls. The pest complex shift phenomenon was confirmed as farmers aimed 60% of target-oriented insecticide controls at sucking pests, principally aphids even more than Lygus bugs. Three quarters of farmers were not content with Bt cotton profitability while providing a shorter protection time and most of them displayed a lack of proficiency in implementing chemical pest control. The remaining quarter of contented farmers carried out more pest target-oriented insecticide controls. Four spraying strategy factors were found and were associated notably with farmers' attitudes in controlling bollworms, aphids and Lygus bugs. The observed strategies were connected with distinct farming efficiency in a country where farming has lost its attractiveness. Sustainable use of Bt cotton calls for locally adapted actions to improve farmers' proficiency in pest control.