2017 ASHS Annual Conference

In the Northeastern US, day-neutral strawberry cultivars fruit continuously from mid-summer until fall frost in the planting year. Preliminary studies indicate covering plants with plastic-covered low tunnels can increase marketable yield and berry size, and provide protection from potentially damaging weather events. The objective of this study was to compare yield, fruit quality, and runner production for strawberry cv. Albion grown on raised beds with three mulch treatments: black plastic, white plastic, and unmulched; and under five cover treatments: KoolLite Plus (KL+) Tufflite IV (TIV), Experimental UV-Blocking (UV-B), Experimental UV-Transparent (UV-T), and no low tunnel. Experiments were conducted in Durham, NH and at Rock Springs, PA in 2016. A replicated split plot design with four replicates was used, with mulch type serving as the main plot and cover type the sub-plot. In both locations, the presence of low tunnels significantly increased the percent of marketable fruit produced (p < 0.001). Under low tunnels, the percent marketable fruit averaged 83% in NH and 60% in PA. Without low tunnels, the percent marketable fruit decreased to 71% in NH and 40% in PA. Cover treatment also affected total marketable yield (g/plant) in NH (p < 0.05) and PA (p < 0.001). In NH, yields were higher under UV-T than TIV (p ≤ 0.05). In PA, plants under low tunnels (regardless of cover type) producing higher yields than those without low tunnels (p ≤ 0.05). Yield was also strongly influenced by mulch in PA (p < 0.001), where percent marketable yield was highest on unmulched (63%) and lowest on white plastic mulch (50%). However, in PA total marketable yield by weight (g/plant) was significantly higher on black and white plastic mulches than for unmulched treatments, at 231 and 250 g/plant, versus 150 g/plant, respectively (p ≤ 0.05). Total yield was not affected by mulch in NH, and averaged 354 g/plant. Mulch and cover treatments did not affect fruit soluble solid content at either site for a single mid-September sample date. However, sequential sampling in NH showed that sampling date did significantly affect berry soluble solid content (p < 0.0001). We conclude that fruit yields and quality may be maximized by producing day-neutral strawberries under low tunnels.