2019 ASHS Annual Conference

Most winter squash consumed in Oregon from December through April is imported. Locally produced squash rots in storage before December due to a high incidence of blossom end rot (Fusarium culmorum). This project evaluated the impact of variety and irrigation on squash production and storage for January sales. Sixteen varieties of squash, including varieties from Cucurbita maxima, C. moschata, C. pepo and one C. maxima x C. moschata interspecific hybrid ‘Tetsukabuto’ were grown in three split-plot field trials (OSU 2016, OSU 2017, and WhiteOak 2017), with irrigation (overhead vs no irrigation) as the main plot and variety as the subplot. No irrigation is considered dry farming in this region as there is essentially no summer rainfall. All treatments were stored in a barn bay with fluctuating temperature (maintained above freezing) and relative humidity. Dryland yields were 43.0% (OSU 2016), 25.3% (OSU 2017), and 52.4% (WhiteOak 2017) of irrigated yields (P ≤ 0.001). The highest yielding OSU 2016 irrigated varieties were ‘North Georgia Candy Roaster’ (NGCR, 62.8 tha^-1) and ‘Tetsukabuto’ (62.4 tha^-1). In OSU 2017, ‘NCGR’ had the highest irrigated yield at 118 tha^-1 with ‘Small Wonder’, ‘Silver Bell’, ‘Tetsukabuto’, and ‘Early Remix’ coming in second. For dryland production, ‘Small Wonder’ was the highest yielding for OSU 2016 and WhiteOak 2017, at 73.5 and 36.1 tha^-1 respectively. ‘Small Wonder’, ‘NCGR, and ‘Silver Bell’ had the highest yields for OSU 2017 (26.6, 26.6 and 25.8 tha^-1 respectively). ‘NCGR, ‘Small Wonder’, ‘Tetsukabuto’ and ‘Early Remix’ were high yielding across all irrigated experiments. ‘Small Wonder’ and ‘NCGR’ were highest yielding across all dryland experiments. Dryland yields were lower in 2017 than in 2016 putatively due to higher daytime temperatures during fruit set and fill. Zero irrigation significantly reduced the incidence of storage rots. In January, the average percent loss in storage was applied to the average yield at harvest to determine the relative yield after four months of storage. Under barn bay conditions, the highest relative yielding varieties under irrigation were ‘Tetsukabuto’ (45.1 tha^-1), ‘Small Wonder’ (37.1 tha^-1), and ‘Winter Sweet’ (30.0 tha¹); for dryland production, the top performers were ‘Small Wonder’ (45.4 tha^-1), ‘NCGR (26.7 tha^-1), and ‘Silver Bell’ (24.3 tha^-1).