ABSTRACT
Predator abundances were quantified in six cover crops to examine their potential as relay strip crops for predator enhancement in cotton in 1995-96 in Munday, TX. Strip crop treatments included 3 fall crops [fall canola, vetch, and wheat], 3 spring crops [spring canola, forage sorghum, and grain sorghum], a relay system comprising canola planted in the fall and grain sorghum in the spring. Cotton planted adjacent to cotton served as a check. Potential of each strip crop for enhancing predator abundance in cotton was evaluated by quantifying the predator abundances in cotton adjacent to each strip crop treatment. Also, the efficacy of each strip crop in suppressing pest populations in cotton was assessed by quantifying the abundances of cotton aphids and bollworms in cotton planted adjacent to each strip crop.<B> </B> Among fall crops, vetch had higher predator numbers than canola or wheat. Spring crops did not differ in their ability to support predators, and they had lower abundances compared with the fall strip crops. Predator abundance in cotton was significantly affected by strip crops, with the highest predator numbers adjacent to grain sorghum, canola-sorghum relay, and vetch. Predator numbers in cotton were not significantly impacted by canola, wheat, or forage sorghum. The canola-sorghum relay system resulted in the lowest aphid abundance in cotton; strip crops did not significantly impact bollworm abundance in cotton.
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