2017 ASHS Annual Conference

While numerous studies have investigated the effect of biodegradable mulches on crop yield, few studies have evaluated their effect on post-harvest crop quality. This study compared five biodegradable mulches (BioAgri^®, Exp PLA/PHA, Organix, and Naturecycle, WeedGuardPlus), with polyethene (PE) mulch and a bare ground treatment for pumpkin (Cucurbita pepo cv. Cinnamon Girl) fruit quality at harvest and over 8 weeks of storage at two diverse locations in the U.S., Mount Vernon, WA and Knoxville, TN, across two years (2015 and 2016). Pumpkins were stored at ambient conditions at each location for 8 weeks postharvest, and fruit quality was measured at harvest and every 2 weeks thereafter: fruit size (length and diameter measured only at harvest), total soluble solids (TSS), and percent dry matter. Pumpkin fruit size did not differ due to mulch treatment. While TSS in 2015 did not differ due to treatment, in 2016 TSS was highest for all plastic mulches (7.96 °Brix on average), intermediate for WeedGuardPlus (7.78) and lowest for bare ground (7.49) (P = 0.02). Overall, TSS increased from harvest to 2 weeks of storage and then declined over storage. Percent dry matter did not differ due to mulch treatment either year, and did not differ over 8 weeks of storage. Thus biodegradable mulches were comparable with PE mulch in pumpkin fruit size, TSS and dry matter.