2017 ASHS Annual Conference

Crop production within high tunnels in the central U.S. has greatly expanded. High tunnels are used primarily to protect intensive, specialty crops like strawberries from harsh environmental changes. Spring-planted, day-neutral strawberry (Fragaria x ananassa) production within high tunnels could provide growers with enhanced yields and marketability, improved storage quality, and late-season prices. High Tunnel, day-neutral strawberry production in the central U.S. may be limited by high summer temperatures. Evaporative cooling (EC) within a high tunnel is a novel method meant to cool the plant temperature. Currently, EC is implemented during plant initation. This study identifies the most successful cultivars in a plasticulture, high tunnel system with or without EC in regards to yield, marketability, feasibility, and quality. The trial was conducted at Kansas State University Olathe Horticulture Research and Extension Center (OHREC) during 2014 and 2015. Mature fruit (90-100% red) of six commercially-available cultivars (‘Albion’, ‘Evie 2’, ‘Monterey’, ‘Portola’, ‘San Andreas’, and ‘Seascape’) were harvested twice per week to monitor total and marketable yield, while four harvests were evaluated for at-harvest and postharvest quality each year. Physical and organoleptic measurements (texture and color, and soluble solids content (SSC) and titratable acidity) were evaluated every other day, while nutritional quality (total phenolic and antioxidant capacity) was evaluated at-harvest. Additionally, respiration rate, moisture content and overall visual quality, using a scale from 5 (excellent) to 1 (very poor), was monitored every 24 hours. Our results indicated that ‘Portola’ had the highest total yields in 2014 and 2015 at 1.33 lbs/plant and 1.12 lbs/plant, respectively. At-harvest and postharvest quality results show ‘San Andreas’, ‘Monterey’, ‘Portola’, and ‘Albion’ had firm texture (P < 0.0001). SSC was highest for ‘Monterey’ and ‘Albion’ (P < 0.0001). All present cultivars met desired ORAC, FRAP, and total phenolic levels, although ‘Evie 2’ had higher nutritional capacity by ORAC (P < 0.0001) and total phenolic (P < 0.001). ‘Albion’, ‘Monterey’, ‘Portola’, and ‘San Andreas’ maintained overall visual quality until day 8, had lower respiration rates, and less moisture content loss (P < 0.001, P < 0.0001, P < 0.05). ‘Seascape’ respired at a greater rate (P < 0.0001) and had low overall visual quality (P < 0.01). EC did not affect yield and changes in quality were inconsistent; this requires further study. Our results indicated that day-neutral strawberries in a high tunnel in the central U.S. can be feasible based on yield and quality of the present study.