Hail Damage to Upland Cotton 1

There has been very little scientific data published on the effect of hail damage on Upland cotton (L.) because of the nature of the problem and difficulty in setting up an appropriate, experimentally sound investigation.A hailstorm on June 26, 1971 made it possible to collect data on the effect of differential damage to individual Upland cotton plants. Three injury classes were established: 1) slight — some stem and leaf damage; 2) moderate — terminal bud lost plus some leaf and stem damage; 3) severe — terminal bud lost plus extensive stem and leaf damage. Effects of hail damage were determined by tagging 5 plants per injury class within each of 10 replications of 5 cultivars. Data were obtained from each of the five plants per injury class for each of the characteristics reported.An application of 47 kg/ha additional N after the hailstorm did not increase the yield of cotton. The lack of response to N, however, may have been caused by the 78 kg/ha N applied before the hail damage occurred. This amount of N is usually adequate for cotton grown on Cecil sandy loam. The number of productive plants was significantly higher in the slight- and moderate-injury classes than in the severe class. As injury increased, individual plant yield decreased significantly in a ratio of 5:3:1 for the slight, moderate, and severe classes, respectively. Plants in the severe-injury class had a lower lint percentage than plants hi slight- or moderate-injury classes. There was no significant effect on fiber length or strength, but finer fibers were produced by plants in the severe-injury class.