Effect of Liriomyza trifolii (Diptera: Agromyzidae) Larval Damage on Growth, Yield, and Cosmetic Quality of Celery in Florida

Abstract

An experiment done near Belle Glade, Fla. compared the growth and yield of celery protected from Liriomyza trifolii (Burgess) damage by weekly applications of cyromazine with celery that was unprotected from leafminer damage. In 15 plantings, leafminers had no significant effect on the growth or yield of celery. Our data show that a substantial amount of leafminer damage can be tolerated by celery plants in southern Florida without a significant reduction in growth rate or yield. In another experiment populations of L. trifolii were manipulated with cyromazine so that field plots of celery were made vulnerable to larval leafminer damage during the first, second and third month of the 3-mo growing season. Celery exposed to leafminers during the first or second month had cosmetic quality similar to celery receiving cryomazine applications weekly throughout the growing season. Celery exposed to leafminer feeding during the last month had quality losses similar to or greater than the untreated check. Therefore, celery apparently must be protected from leafminer damage only during the final month of the growing season in Florida to prevent losses in quality. Even low leafminer densities during the last month caused considerable quality loss, indicating that control must be extremely effective during that time to produce a marketable crop of celery.