In North Carolina, double cropping cotton (Gossypium hirsutum L.) and wheat (Triticum aestivum L.) often results in sub-optimal cotton yield and minimal investment return, most often due to lack of sufficient stand as a result of moisture limitations and a short growing season. Relay intercropping of cotton in wheat prior to harvest may be an alternative to traditional double cropping. A relay intercropping system was tested at five locations over three years in North Carolina to determine thrips infestation, cotton yield, and economic return following relay intercropping of cotton and wheat. Relay intercropped wheat yield ranged from 65% to 85% of conventional wheat plantings. Cotton yields were not affected by the presence of relay-intercropped wheat, but plant maturity was delayed in some experiments. Intercropped cotton plants exhibited similar morphology to cotton planted in a traditional strip tillage system with wheat terminated two wks prior to planting with increased nodes above cracked boll, suggesting delayed plant development. In four of five locations, thrips (Thysanoptera: Thripidae) populations were lower in the intercropped cotton, most likely due to interference of the ability of thrips to locate cotton seedlings. Thrips levels when seed was treated with abamectin plus thiamethoxam plus azoxystrobin and an additional in-furrow application of aldicarb or acephate applied to foliage were less than that of seed treated with azoxystrobin alone. Estimated economic return of intercropped cotton and wheat equaled that of conventional cotton planting and exceeded double cropping of wheat followed by soybean [Glycine max (L.) Merr.] most years when cotton, soybean, and wheat prices were set at $1.98 kg-1 lint, $0.44 kg-1, and $0.25 kg-1, respectively.
