Effects of Population Density and Nitrogen Rate in Ultra Narrow Row Cotton

Abstract

A field study was conducted to investigate the effects of population density and nitrogen rate on yield, growth, and fiber response of ultra narrow row (UNR) cotton. Stand loss occurred at densities greater than 22 plants m − 2 and nitrogen rates greater than 56 kg  ha − 1 and stand loss exceeded 20% at harvest. Seed cotton yields were similar across populations and rates of 56, 112, and 168 kg  ha − 1 . Nitrogen rates greater than 56 kg  ha − 1 resulted in greater vegetative growth based on increased plant height and number of nodes. These results indicate that populations of 22 plants m − 2 and nitrogen rates of 56 kg  ha − 1 were sufficient for maximum yields in UNR cotton under our conditions. However, at higher nitrogen rates, boll formation increased at lower nodes with no corresponding change in yield. Higher nitrogen rates may promote earliness and distribute yield across more fruiting sites.