Submitted to: Scholarly Research Exchange
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2009
Publication Date: 9/30/2009
Citation: Molin, W.T., Hugie, J. 2009. Effects of Plant Population and Nitrogen Rate in Ultra Narrow Row Transgenic Cotton. Scholarly Research Exchange, Vol. 2009, Article ID 868723. Published on line. DOI: 10.3814/2009. Interpretive Summary: Cotton yield potential has reached a plateau, thus growers are looking at alternative management systems to attain increased productivity. In this research, the effects of plant populations and nitrogen rates were evaluated on cotton grown in ultra narrow row cotton (UNR) production systems to determine optimal growth conditions. The results show that a lower plant population and a reduced nitrogen rate were sufficient to achieve maximum yields and reduce production costs. The research establishes conditions for UNR cotton production specific to the Mississippi Delta and can pave the way for future improvements in producing cotton in narrow row spacing.
Technical Abstract: A field study was conducted in 2000, 2001 and 2002 at Stoneville, MS, to investigate the effects of plant population and nitrogen rate on growth and yield responses of cotton grown under ultra narrow-row (UNR) conditions. Seedling establishment to the cotyledon stage was similar at all populations and nitrogen rates. At harvest, stand counts revealed that there was loss in stand as population increased in each year and reached 30 % in 2000. Seed cotton yields were similar between populations indicating that higher populations provide no yield advantage and this finding was reflected in the decrease in bolls plant-1 as population increased. Boll numbers paralleled yield response for population and nitrogen rate in this system. Increasing population resulted in decreased boll numbers for a ten plant sample. Increasing nitrogen rate resulted in an overall increased in bolls plant-1 however, at nodes 4 to 8 there was a loss of bolls. Increasing nitrogen rate increased plant height, number of nodes and the height-to-node ratio. Population had no effect on height but number of nodes decreased. These results indicate that populations greater than 22.2 plants m-2 and nitrogen rates of 56 kg ha-1 were sufficient to obtain maximum yields in UNR cotton under our conditions.