Influence of Clomazone Herbicide on Postharvest Quality of Processing Squash and Pumpkin

Certain cultivars of processing pumpkins and squash, such as Golden Delicious and Butternut squash, are more sensitive to application of clomazone (Command herbicide) than others, resulting in paler coloration of fruit tissues-an undesirable condition for food processors. The objective of this research was to evaluate the influence of clomazone on fruit color retention over time in six processing squash and pumpkin cultivars that exhibited various degrees of clomazone sensitivity. Color retention was monitored by total carotenoid content after curing. Relative levels of fatty acids and peroxidase (POD) and lipoxygenase (LOX) enzyme activities, associated with membrane and pigment integrity in higher plants, were assayed. Total carotenoid content of treated tissue varied, with Golden Delicious and Butternut squash significantly affected by herbicide treatment. Treatments of clomazone resulted in increased POD activity in Turk’s Turban and Buttercup squash. No difference was observed for LOX activity in treated or control samples.