Articles
EFFECTS OF DIFFERENT SULPHATE LEVELS AT THE ROOT ZONE ON THE CONCENTRATION OF MINERAL COMPOUNDS IN THE LEAVES OF GREENHOUSE TOMATO GROWN ON NFT
The plants were grown (2000 and 2001 year) in the rockwool slabs of three independent units of the NFT system, fertigated with the nutrient solutions containing three sulphate levels (mM): I-2.1, II-4.2, III-6.25. During the plant growth, the rate of accumulation of sulphates in the nutrient solutions were studied and at the end of experiment, the concentrations of sulphates were 8.3-10.4 and 9.4-14.6 mM in the I and II-III solutions, respectively.
There were no any toxic effects of high sulphate levels both on growth and yield of tomato.
The mineral composition of leaves and roots were determined at three stages of plant maturity, i.e. flowering of 1st and 2nd cluster, ripening of fruits on 1st cluster and fruits at full harvest.
There were significant treatment effects on mineral composition of leaves and roots of tomato.
The plants grown on the highest sulphate solution containing the highest levels of K, S and N and the lowest of Mg.
Aging of plants decreased N, P, K and Mg levels.
The highest K levels were shown at the first stage of maturity.
Then, the concentration of K decreased and Ca increased.
There were no treatment effects both on yield and quality of fruits.
