Research was conducted to determine the effect of planting pattern, plant density, and levels of weed management intensity on intercepted photosynthetically active radiation (IPAR), weed control, and cotton lint yield in glyphosate-resistant cotton. Twin-row planting pattern canopy IPAR was 55% 7 wk after emergence (WAE) and 76% 9 WAE compared to 48% for single-row planting pattern 7 WAE and 59% 9 WAE. Regardless of cotton density, row spacing, or weed management intensity, control of browntop millet and Florida beggarweed was at least 88% 18 WAE. Benghal dayflower, sicklepod, and smallflower morningglory control was greater in twin-rows compared to single-rows at a cotton density of 7 plants m−2. Control of Benghal dayflower and sicklepod increased when cotton density increased at low weed management intensities; however, cotton density had no effect on weed control at higher levels of weed management input. At a cotton plant density of 7 plants m−2, twin-row cotton yielded 220 kg ha−1 more than the single-row planting pattern. Data indicates twin-row cotton production is feasible and that control of various weeds was better in twin-row than single-row pattern at lower cotton density and weed management intensity.
Nomenclature: Glyphosate; MSMA; prometryn; S-metolachlor; Benghal dayflower, Commelina benghalensis L. COMBE; browntop millet, Urochloa ramosa (L.) Nguyan PANRA; Florida beggarweed, Desmodium tortuosum (Sw.) DC. DEDTO; sicklepod, Senna obtusifolia (L.) Irwin and Barneby CASOB; smallflower morningglory, Jacquemontia tamnifolia (L.) Griseb. IAQTA; cotton, Gossypium hirsutum L.