ABSTRACT
A 5-6 year cropping-systems study was initiated in 1988 near Corpus Christi, Texas to determine the influence of reduced tillage vs. conventional tillage, and high level insect management vs. conventional insect management on insect pest numbers and damage, and yields on cotton. The plot design was randomized complete block with split-split plots within a block. The main effects were crop (sorghum, cotton, or corn), with a split for conventional tillage vs. reduced tillage, and second split for conventional insect management vs. high level insect management. Plots were sampled for insect pest numbers and damage when appropriate. Numbers of aphids were significantly greater under reduced tillage in 1988. High level management with insecticides significantly reduced numbers of aphids, boll weevil damaged buds, and cotton fleahoppers in 1989. There was a significant tillage x management interaction for boll weevil damaged buds in 1989. Yields at first harvest tended to be higher with high level management in 1989. The highest total yields for both years were in the conventional tillage under high level insect management, but they were not significant. Very droughty conditions in both years may have influenced the results of this dryland farming systems study.
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