Ernest L. Clawson1, Jack. E. Jones2, and Joshua S. Price1. (1) LSU AgCenter, P.O. Box 438, St. Joseph, LA 71366, (2) JAJO Genetics, 246 Maxine Dr., Baton Rouge, LA 70808
The dwarf red cotton (Gossypium hirsutum L.) variety CSA0107 B2RF (Monsanto Cotton States) has a growth habit that generally prevents canopy closure in conventional row (CR) spacings, suggesting that ultra-narrow row (UNR) systems would be advantageous to yield in this variety. The study objectives were to compare lint yield of both a red dwarf and a normally-statured cotton variety in a UNR and a CR system. The location was the LSU Agricultural Center's Northeast Research Station, Saint Joseph, LA. Each system was planted on a wide raised bed, with 4 rows (averaging 20 inches wide) per bed in the UNR treatments and 2 rows (40 inches wide) per bed in the CR treatments. Plant populations were elevated by approximately 50 percent in UNR treatments. Few treatment effects were observed on lint percentage and fiber quality. Lint yield was significantly decreased by the UNR system relative to the CR, although the difference between means was small. Lint yield was significantly and substantially lower for the dwarf red variety than for Stoneville 4554 B2RF. Despite the benefits of the UNR system to canopy closure in the dwarf red variety, the lint yield of each variety responded similarly to row spacing and the interaction between these factors was not significant. The data suggest that reduced lint yields of the dwarf red variety in CR systems may originate at least partially with factors other than a lack of canopy closure. The UNR system was not beneficial to yield in any variety.
