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Description:
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Ultra -narrow row (UNR ) cotton (Gossypium hirsutum L . ) is a production system using high plant populations in reduced row spacings . The responses of this production system to nitrogen fertilizer have not been fully investigated . Evaluations of yield and earliness of harvest are also important .
A three -year study was conducted at the Texas Agricultural Experiment Station farm , Burleson County , TX , on a Ships clay (very -fine , mixed , active , thermic Chromic Hapluderts ) and a Weswood silty clay loam (fine -silty , mixed , superactive , thermic Udifluventic Haplustepts ) . A split plot design was used . Nitrogen fertilizer rates of 0 , 50 , 101 , and 151 kg N ha -1 were applied as the whole plots and row spacings of 19 , 38 , and 76 cm were established as the split plots . Data included lint yield and yield components , as well as earliness of crop maturity and earliness -related parameters such as boll distribution .
Lint yield was increased by higher nitrogen rate . There was no nitrogen rate by row spacing interaction on lint yield , implying fertilizer rates do not need to be changed for UNR systems . Reductions in row spacing did not significantly affect lint yield in any year . Responses such as reduced bolls per plant , increased plant populations , increased ginout , and decreased boll size were often significant and combined to allow the crop to maintain equivalent yields as row spacings were reduced . The slight UNR earliness advantages were probably due to changes in boll distribution . Based on these results , increases in lint yield and earliness may not reliably contribute to the profitability of UNR cotton . |