ALTERNATIVE METHOD OF OPTIMIZING YIELD OF TOMATOES IN A CLOSED HYDROPONIC SYSTEM
A study was conducted in a shade-net structure to evaluate the effect of early decapitation combined with high density plantings on tomato yield and quality in a hydroponic system. Plants were grown in a closed hydroponic (gravel-film technique) system using granite rocks as a substrate. The growing points of all plants were removed between the second and third inflorescence at 30-35 days after transplanting with two leaves remaining above the second inflorescence. In the first experiment (Exp. 1), plants were subjected to four plant densities i.e., 8, 16, 20 and 25 plants/m2 using tomato cultivar FA593. In the second experiment (Exp. 2), two tomato cultivars, i.e., FA593 and Rodade were used at four plant densities i.e., 10, 16, 20 and 25 plants/m2. For each experiment a randomised complete block design was used with five replicates. Total, marketable and unmarketable yields, as well as physiological disorders were recorded. In Exp. 1, results showed highest total yield and number of marketable fruits per unit area at a spacing of 25 plants/m2 although not significantly different to 20 plants/m2. Results in Exp. 2 showed similar results with significantly higher values of all variables at the highest density (25 plants/m2). The incidence of fruit cracking decreased with an increase in plant density. Cultivar FA593 produced significantly higher total yield, marketable yield, number of marketable fruits, fruit exhibiting cracking and blossom-end rot as compared to cultivar Rodade. Results demonstrate that tomatoes pruned back to two trusses, combined with high density planting in a closed hydroponic system can achieve high yield of good quality with a shortened growth season.
Maboko, M.M. and Du Plooy, C.P. (2013). ALTERNATIVE METHOD OF OPTIMIZING YIELD OF TOMATOES IN A CLOSED HYDROPONIC SYSTEM. Acta Hortic. 1007, 579-585
fruit cracking, cultivars, gravel-film technique, plant density, pruning, trusses, yield