Alteration of cotton source-sink relations with plant population density and mepiquat chloride

作者：Gwathmey C O^*; Clement J D

来源：Field Crops Research, 2010, 116(1-2): 101-107.

DOI：10.1016/j.fcr.2009.11.019

• Gossypium hirsutum
• Cotton
• Source-sink relations
• Plant population density
• Mepiquat chloride
• Starch reserves

Improvements in carbohydrate source-sink relations are needed to improve efficiency of yield formation in cotton (Gossypium hirstitum L.). Most source-sink research has focused on leaf-boll relationships, with little Study of vegetative storage reserves. Possible ways of altering the source-sink balance include increasing the plant population density (PPD) and using a plant growth regulator, mepiquat chloride (MC). We evaluated effects of PPD and MC on plant growth and development, stem starch reserves and lint yield in a 3-year field experiment at Milan, Tennessee. Row spacings of 25, 51, and 102 cm averaged 17.6. 13.2, and 8.3 plants m(-2), respectively. Mepiquat chloride rates were 0 and 86 g ha(-1). Higher PPD in narrower rows tended to reduce boll number more than leaf area per plant, reducing the number of bolls per unit leaf area. However, boll distribution was more concentrated, implying more synchronous demand for photosynthate in 25-cm rows than in wider rows. Stem starch concentrations during boll filling were similar to, or slightly lower, in 25-cm rows than in wider rows. Findings are consistent with the hypothesis that availability of photosynthate may limit boll load at higher PPD, despite more leaf area per boll. Application of MC tended to reduce leaf area per plant more than boll load, and to increase the number of bolls per unit leaf area. The MC treatment also concentrated the boll set on lower sympodia, increasing the synchrony of boll maturation and demand for photosynthate. Application of MC increased boll set percentage and decreased stem starch reserves slightly. Lint yields were increased by MC application in finger-stripped 25- and 51-cm rows in 2 of 3 years, by an average of 11%, but not in spindle-picked 51 - and 102-cm rows. Findings support the hypothesis that MC benefits boll set and yield formation in narrow-row systems by reducing LAI. Source-sink alteration with PPD and MC may be useful in future research to improve carbohydrate use and yield formation in cotton.

• 出版日期2010-3-3