Crop Biotech Update

Study Shows that Nearby Crop Diversity Mediates the Effect of Bt Cotton on Insect Community

May 29, 2019

Researchers from Chinese Research Academy of Environmental Sciences and CSIRO Agriculture and Food conducted a comprehensive study to investigate the effect of large-scale cultivation of GM crops on agricultural biodiversity.

They compared the number of species, population abundance, community evenness and dominance of insects and weeds in Bt and non-Bt cotton fields in 27 locations in northern China. To verify the results of the study, they also conducted a three-year field experiment. Results showed that weed diversity in both fields was similar, but the number of species and diversity indices of insects were lower in Bt cotton fields, aligning with fewer leaf damage to broadleaf plant species including cotton as well as crops in nearby plots. The leaf damage in Bt and non-Bt cotton negatively links with the diversity of neighboring crops in cotton fields.

Based on the findings, the researchers concluded that the neighboring crop diversity mediates the effects of Bt crops on agricultural diversity in complex interactions among transgenic crops, in-field weed and insect communities, and neighboring crops.

More results are available in Transgenic Research.