Four cotton varieties were treated with the 0.5 lb/ac rate of vanadium at five locations in South Texas. Applications were made individually at two weeks following early squaring and two weeks post-bloom. All tests were replicated and arranged in RCB designs. Lint increases up to 10.5 percent were achieved in 50 percent of the tests. At Port Lavaca, Tx, only the post-flower treatment was significant at the 5 percent probability level with 83 additional lint pounds. The post-square application provided 72 (NS) additional lint pounds. Increases were observed due to a greater number of bolls produced rather than heavier boll weights. No changes occurred in fiber quality.