THE AIRPLANE WAS BEING USED IN AN AERIAL APPLICATION FLIGHT TO SPRAY COTTON. DURING DESCENT FROM A TURN-AROUND MANEUVER, THE RIGHT WING OF THE AIRPLANE STRUCK THE GROUND AND SEPARATED FROM THE AIRFRAME. WITNESSES REPORTED THUNDERSTORMS IN THE AREA WITH WINDS GUSTING FROM 15 TO 30 KNOTS. NATIONAL WEATHER SURFACE RADAR SUMMARY REPORTS INDICATED RAINSHOWERS AND THUNDERSTORMS. EXAMINATION OF THE AIRPLANE DID NOT DISCLOSE ANY MAINTENANCE ANOMALIES.