Submitted to: ASAE Annual International Meeting
Publication Type: Abstract only
Publication Acceptance Date: 7/26/2003
Publication Date: 9/1/2003
Citation: Fleisher, D.H., Both, A., Logendra, L., Moraru, C., Gianfagna, T., Lee, T.C., Cavazzoni, J., Janes, H. 2003. Manipulation of tomato fruit quality through temperature perturbations in controlled environments [abstract]. ASAE Annual International Meeting. Paper No. 34102. Interpretive Summary:
Technical Abstract: Quality factors such as size, color, taste, and nutritional content are important criteria for marketing of greenhouse tomato fruit. Most research studies focused on post-harvesting and storage effects on several of these factors. Environmental conditions under which the tomato plant was grown and the time for which the fruit is allowed to ripen on the vine also influence the quality of the fruit. Controlled environment studies demonstrated that air temperatures effect developmental rate of tomato plants and size of the tomato fruit. The rate of starch biosynthesis (which effects fruit sink strength and thus the final sucrose content at maturity) is at its highest between 10 and 35 days after fruit-set. This period will likely be a point where other biochemical changes in the fruit occurs that influence fruit quality. Growth chamber experiments were initiated with tomato (cv. Laura) to study effects of a two-week air temperature perturbation applied during fruit-set on fruit quality, time to harvest, and harvest window. Plants were grown in 6" pots and pruned to the first fruit cluster. Nutrients were provided through a drip irrigation system. All plants were grown under the same environmental conditions except for a two week period beginning ten days after fruit-set, during which plants were assigned to one of three treatments, 28/23°C, 23/18°C, and 18/13°C. Five tomato fruits were harvested from each plant at three distinct physiological ages defined by the breaker stage (the point at which 25% of the fruit begins to turn red), breaker stage plus three days, and breaker stage plus six days. Harvested fruits were analyzed for mass, size, color, soluble solids content, pH, acidity, viscosity, and other quality parameters. Initial results show significant temperature effects on individual fruit size, mass, developmental rate, and fruit processing characteristics. The results are applicable towards the development of more efficient plant production strategies for greenhouse growers.