Comparing early season fruit retention across different physiogeographic regions of Texas

摘要

A comparison of early season fruit retention among cotton cultivars was examined from 1997 to 2000 for three dryland cotton growing regions of Texas: Coastal Bend, Southern Blacklands, and Northern Blacklands. All regions were tested due to their similar cotton production practices, similar soil structure (clay) and similar weather patterns. All fruit retention data were captured from Delta and Pine Land Company's Agronomic Systems Trials (AST) in conjunction with variety testing that were conducted with producers in commercial cotton fields. Fruit retention data showed that the Coastal Bend had the highest level of early season retention for every year tested and each year the data were significant. The Southern Blacklands was second in early season fruit retention in every year and the Northern Blacklands was third in each year tested. All data were also significant for the Southern and Northern Blacklands for each year tested. There was no interaction among varieties tested on fruit retention.All varieties within a region had similar fruit retention patterns so to be region specific and not variety specific. Examination of causes of fruit retention differences found no environmental explanation as to why differences in early season fruit retention occur between regions. Analyzing differences in early season insect pressure found that cotton fleahopper, Pseudatomoscelis seriatus (Reuter), densities have a negative effect on early season fruit retention. Linear regression analysis of fruit retention versus cotton fleahopper densities showed a significant negative relationship for the Northern and Southern Blacklands. This is to say that increasing cotton fleahopper densities subsequently lowered early season fruit retention. Lint yield was then regressed against early season fruit retention for each region for each year. This found that both the Coastal Bend and Southern Blacklands had negative relationship although not significant. This trend implies that lint yield increases were not dependent on early season fruit retention. The Northern Blacklands showed a positive yield response to increases in early season fruit retention although not significant which implies that increasing early season fruit retention increased lint yields. The Coastal Bend and Southern Blacklands regions showed a negative yield response to increases in early season fruit retention although the trend was not significant.