Effect of Foliar-Applied Salicylic Acid on Cotton Flowering, Boll Retention, and Yield

Salicylic acid (2-hydroxybenzoic acid) may help regulate several plant functions, including systemic acquired resistance to pathogens and the formation of flowers. The objective of this study was to characterize the effects of foliar-applied salicylic acid on cotton (Gossypium hirsutum L.) flowering, boll retention, and yield. Field experiments were conducted at two Mississippi locations in 1995 and at one location in 1997. In 1995, a single application of sodium salicylate (O,17.1,5 1.3, or 171 g ha-') was made two to three weeks prior to flowering. In 1997, nine sequential applications of sodium salicylate (51.3 g haF') or salicylic acid (44.3 g ha-') or a check solution (Tween 20, polyoxyethylene sorbitan monolaurate only) were made beginning when the first floral buds were present and ending at first flower. In one of the 1995 tests and in the 1997 test, the cotton was not treated with insecticides after planting. Although physiological responses to exogenously-applied salicylic acid on cotton have been reported elsewhere, in the present study, flower production, boll retention, and yield were not significantly affected.