Abstract
This study was conducted to clarify the changes in nutrient uptake and its transport to plant organs during the developmental stage in tomato plants grown in the nutrient solution culture under the different seasonal conditions. Results are as follows. 1. The growth stage of tomato plant during the 110-day-culture period was divided into three growth stages. In the first 20 days after sowing, giving ‘leafy’ vegetative growth stage, the SGRs (Specific Growth Rate) of leaves were greater than those of stems. In the second stage from 30 to 70 days after sowing, giving ‘stemy’ vegetative growth stage, the SCRs of stem was greater than those of leaves. In the third stage during the period after 70 days from the sowing, giving fruit growth stage, the SGRs of fruits had the highest value as compared with those of leaves and stems. 2. The SARs (Specific Absorption Rate) of inorganic nutrients in plant were declined with age. Their SARs gave the maximum value in the order of N, K, P during the vegetative growth stage. In the fruit growth stage, the SARs of Ca in leaves were increased with age. The SARs of N and K in fruit were maintained at higher values during the period of fruits development. Inorganic nutrients required were N and K during the first and third (fruiting) stages, being P and Mg during the second stage. 3. The SARs of P and K in leaf, stem, and fruit were high in summer, whereas those of Ca were low in summer or high temperature season, although the SARs of Ca in aged leaves in summer were greater than those in winter. The uptake of Ca in an early stage of fruit growth was inhibited at high temperature.
