differences in cultivar maturity, but the voluminous data is difficult to analyze and summarize. In May 1994 yield trials were planted near Princeton, NC and Keiser, AR. In late September 12 consecutive plants in 3 reps of 25 entries were mapped for the presence of harvestable bolls. The percent of mapped bolls at each boll site was multiplied times a set maturity value and the product was then summed over sites to generate a plant map index (PMI). The maturity value of sites decreased by 3 each node up the stem and by 9 each position out a branch. Also, a 5 ft section of each plot was harvested on 3 dates. The interaction of entries and locations was not significant for PMI or % second pick, while locations and entries were significant for both variables. The over location means for PMI and % second pick returned approximately the same ranking of entries. The cultivar CB232 had the highest PMI (36.0) and % second pick (73.6), while DP90 had the lowest PMI (29.1) and DP5415 had the lowest % second pick (53.9). The higher R-square and lower C.V. of PMI suggest it may be more sensitive than sequential harvest. PMI was highly correlated (0.82) with % second pick and it was more quickly and easily obtained. These points indicate that PMI can be used to efficiently discern genetic differences in maturity of cotton germplasm.