Effects of Salinity Treatment Duration and Planting Density on Size and Sugar Content of Hydroponically Grown Tomato Fruits

摘要

Tomato plants were grown using a nutrient film technique in a hydroponic system to evaluate the effects of starting time and duration of salinity treatment and the interaction between salinity and planting density on fruit yield and quality. The electrical conductivity (EC) of the nutrient solution was maintained until the anthesis of plants. Sodium chloride was added to the standard nutrient solution until EC 8.0 dS-m"' and this level was maintained from the anthesis of the first flower truss until the fruit harvest (whole treatment); 8.0dS-nr' solution was applied from anthesis of the first truss until 20 days after anthesis (DAA) (early treatment) and from 20 DAA until the fruit harvest (late treatment). The average fruit weights in the whole, early, and late treatments were 46, 71, and 58% of the control weight, respectively. Fruit radius and cell size were also reduced under each salinity treatment; however, the estimated number of cells per fruit was not significantly affected by the salinity treatment. The levels of total soluble solids (Brix%) were 6.2 in the control and 9.9, 7.7, and 9.1 in the whole, early, and late treatments, respectively. Incidences of blossom-end rot were 0, 33, 25, and 16% in the control, whole, early, and late treatments, respectively. The influence of planting density (8.5-9.5 plants/m2) under saline conditions on fruit size and sugar content was not considerable unremarkable. The fruit yield at high planting density increased more than that at a low plating density under salinity treatment.