Effects of foliar applications of carbohydrates on the yield of cotton (Gossypium hirsutum) lint

Various plant growth hormones and bioregulators have been reported to increase the yield of cotton Gossypium hirsutum L. lint when applied foliarly in held tests. However, while positive effects with these compounds were often observed in individual years by us, multiyear results were not significant. Initial results with a commercial formulation, Foliar Triggrr, FT (Westbridge Agricultural Products, San Diego, CA), in which the stated active ingredient was cytokinin, led us to investigate the composition. Over a several year period (1989-1995), application of a succession of sugar-containing fractions to the cotton plants gave consistent small increases but not statistically significant lint yield increases. The composition of the active carbohydrate fraction upon acid hydrolysis was a mixture of mainly xylose, mannose, galactose, and glucose. Equal molar mixtures of sugars (man, gal, glc, suc) and iota-, kappa-, and lambda-carrageenans (linear sulfated polysaccharides) gave small consistent increases. The commercial application of this lead with carbohydrates may be in the utilization of an economical sugar-processing byproduct.