Effects of nutrient stress by split-root system on the growth and K, Ca, and Mg contents at different stages of hydroponically-grown tomato seedlings

Abstract

Effects of nutrient stress by the split root system on the growth and major cation (K, Ca and Mg) contents were investigated at three stages of hydroponically grown tomato (Lycopersicon esculentum Mill. cv. House Momotaro) in spring and autumn. Nutrient stress was applied to tomato plant seedlings by halving their roots; one part was cultured in 1/2 strength Enshi standard nutrient solution (ESNS), whereas the other was immersed in tap water. Seedlings with intact roots, cultured in 1/2 strength ESNS, were used as non-stressed control. No significant difference was observed in major growth parameters between the stressed and non-stressed plants at three stages. Nutrient stress significantly increased the percentage of dry weight of the split roots cultured in 1/2 strength ESNS at three stages, and that of the shoot 10 days after treatment. The dry weight of the split roots, immersed in tap water, was significantly reduced at three stages. Nutrient stress significantly reduced K contents in leaves and roots at three stages, and also in stems except 20 days after the treatment. Nutrient stress significantly increased Ca content of the split roots, cultured in 1/2 strength ESNS, 10 and 20 days after treatment. A significantly high Mg content was found in the split roots, immersed in tap water, at three stages. Under nutrient stress, leaf and stem Mg contents were increased at three stages. Nutrient stress significantly decreased the EC value of the nutrient solution, and significantly increased the total amount of water absorbed.