ISHS Acta Horticulturae 648: South Pacific Soilless Culture Conference - SPSCC
CONTROL OF FRUIT SIZE IN HYDROPONIC GREENHOUSE TOMATOES |
| Authors: | S. Field, M.A. Nichols |
| Abstract:
Control of individual tomato (Lycopersicon esculentum Mill.) fruit weight during a crop cycle is of commercial benefit to improve marketable yield. Fruit thinning effects on the variability in tomato fruit size was evaluated, with individual fruit weight with in the truss being examined. Three fresh market tomato cultivars, Alboran (Standard), Ophir (Beefsteak) and Cherita (Cherry) were grown, in New Zealand during winter and spring months of 2001, in a greenhouse with NFT at a plant density of 2.76 plants per m2. Each tomato cultivar was fruit thinned to three different levels (3, 4 and 5 fruit per truss for Alboran; 1,2 and 3 fruit per truss for Ophir; 4, 8 and 12 fruit per truss for Cherita). Individual fruit weights within each truss were taken for all fruit thinning treatments. Individual fruit weight down the truss, of all three cultivars, reduced in size by a constant factor or slope. A slope of -13 g / fruit position was observed for Alboran, which was flatter than that of Ophir (-17 g / fruit position) and steeper than that of Cherita (-0.25 to -0.60 g / fruit position). The number of fruit on the truss did not affect the slope of Alboran and Ophir cultivars, while thinning Cherita to 4 fruit per truss produced a significantly steeper slope (-0.60 g / fruit position) than 8 and 12 fruit per truss (-0.25 g / fruit position). More fruit present on a truss, in all cultivars, produced smaller proximal (first) fruit, thus reducing the size of the remaining fruit on the truss proportionately. Individual trusses within Cherita were also shown to have a constant slope of fruit size down the truss. These results suggest that fruit thinning can be used to produce more fruit within the desired marketable fruit size range all year round. However a greater understanding of fruit thinning interactions during different plant densities and growing seasons must first be achieved. | |
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