A test was conducted on the same site from 1980 through 1984 to determine if continuous use of trifluralin would influence Cotton seedling survival (stands) and subsequent lint yields. Ten cotton cultivate were used throughout the test period; nine of the 10 cultivars used from 1980 to 1982 were replaced with nine other cultivars in 1983 and 1984. Coker 310 was used throughout the 5-year period. Individual plot size for the trifluralin versus no-trifluralin study was four 40" rows, 240 feet long. There were 6 replications in the study. Trifluralin rates were 1.0 lb/acre, and the soil type was a Beulah fine sandy loam.

No significant differences in emergence, seedling disease or final stand due to trifluralin was detected in this study; average final stands were 54 and 57% for the no-trifluralin and trifluralin treatments, respectively. Seed cotton was first harvested when the no-trifluralin plots were about 76% open. In 2 of the 5 years, first-harvest lint yields from the trifluralin treated plots were significantly lower than those in the notrifluralin plots; overall, the first-harvest lint yield was 608 lbs/acre in the no-trifluralin plots, but only 517 lbs/acre in plots treated with trifluralin, which indicates a delay in maturity due to trifluralin treatment. Total lint yields, however, were not significantly different between trifluralin treatments in any year. There was no significant interaction for trifluralin X years for lint yield, nor was there any yield trend due to residual soil effects of trifluralin treatment.