Evaluation of Winter Wheat as a Potential Relay Crop for Enhancing Biological Control of Cotton Aphids in Seedling Cotton

Abstract

A 2-year study was conducted to evaluate the role of winter wheat, Triticum aestivum L., as a potential relay crop to conserve arthropod natural enemies and suppress cotton aphids, Aphis gossypii Glover, in seedling cotton. The results suggested that the natural enemies that moved from the adjacent wheat fields to cotton fields with the maturity and harvest of wheat could keep the cotton aphid population at the edges (0-4 m) of cotton fields under the action threshold of 100 aphidS/m(2). Data also suggested that the wheat strip served as a reservoir to conserve arthropod predators and "relayed" its predators to cotton when wheat matured and senesced.