Improving Yield, Quality and Economic Potential of Strawberries Grown in High Tunnels for Kansas

Résumé du livre

Interest in spring day-neutral strawberry production in high tunnels is increasing in the Midwest. Although day-neutral cultivars have a much longer fruiting period than June-bearing cultivars, it is not clear if they will thrive in the summer climatic conditions in Kansas. High temperatures can reduce fruit yield and quality, potentially resulting in poorer fruit marketability and profitability for growers. A recent study at Kansas State University saw that heat-tolerant cultivars could be grown in high tunnels in Kansas when shade cloth was used. Different colored plastic mulches could also be used to change the soil temperature and light intensity, which can help to improve productivity and fruit quality. The goal of this thesis was to determine the best color for plastic mulch for a high tunnel system in regard to productivity, fruit quality, and profitability. A split-plot randomized complete block design was used in trials conducted at the Kansas State University Olathe Horticulture Research and Extension Center in 2020 and 2021. Six plastic mulches (black, white, black stripe, silver, red, and green) were employed, as well as two-day neutral cultivars, 'Albion' and 'Portola'. Throughout the season, soil temperature, UV-A, and UV-B were measured in each plastic plot. All input costs were recorded throughout the growing season to calculate the production budget and profitability of the production system based on crop price and marketability. Three harvests were analyzed for quality, and mature fruit (90% to 100% red) and fruit yield was measured by harvesting strawberry plants twice per week. At harvest and for up to four days of storage, visual quality, respiration, flesh firmness, color, soluble solids content (SSC), titratable acidity (TA), and SSC/TA ratio were measured as well as nutritional quality (total phenolic, antioxidant, and anthocyanin). In our study, total and marketable strawberry fruit yields were greater in 2020 than 2021. In comparison to the (standard) black mulch, the silver mulch had a higher fruit yield, likely due to a reduced temperature range and lower UV-B irradiation capacity (P