The Influence of High-tunnel Production on Yield and Fruit Quality of Organically Grown Tomato

Despite the growing interest in high tunnel vegetable production among organic farmers for producing high-value crops, research-based information is rather limited with respect to crop performance in organic high tunnel systems in Florida, where sandy soils with poor retention of water and nutrients and high pressure of diseases, pests, and weeds often present great challenges to organic production. This experiment conducted in Citra, FL during the Spring 2015 season compared fruit yield and quality of tomatoes grown in organically managed high tunnel vs. open field plots. A split-split plot design with 3 replications was used, with production environment (high tunnel vs. open field) as the whole plot factor, cultivar as the subplot factor, and grafting as the subsubplot factor. Indeterminate tomato ‘Cherokee Purple’ and determinate tomato ‘Tribute’ were grafted onto an interspecific hybrid tomato rootstock ‘Multifort’, respectively, and non-grafted scions were used as controls. Although ‘Cherokee Purple’ had significantly higher average fruit weight, it produced significantly lower total marketable fruit weight and number as compared to ‘Tribute’. Regardless of the tomato cultivar, plants grown in the high tunnel system showed significantly increased total marketable fruit weight and number in contrast to the open field. Average fruit weight and percentage of unmarketable fruit weight and number did not differ between high tunnel vs. open field. Grafting with ‘Multifort’ resulted in significantly higher average fruit weight and total marketable fruit yield than non-grafted tomato plants, but did not affect total marketable fruit number. Root-knot nematode galling index ratings were found significantly lower in grafted tomato plants in both high tunnel and open field plots. With the main purpose of comparing organic tomato fruit quality between high tunnel vs. open field production, tomatoes harvested from grafted and non-grafted plants were combined for quality assessment. ‘Cherokee Purple’ fruit from the open field demonstrated a decrease in postharvest shelf life in comparison with tomato fruit produced in high tunnels. Fruit soluble solids content and titratable acidity of ‘Tribute’ tomato was not affected by the production environment. Interestingly, high tunnel production led to significantly higher levels of lycopene and beta-carotene in ‘Tribute’ fruit, while total phenolic content exhibited similar levels between high tunnel vs. open field.