ISHS Acta Horticulturae 458: International Symposium on Water Quality & Quantity-Greenhouse
EFFECTS OF VARYING SULFATE CONCENTRATIONS AND VAPOR PRESSURE DEFICITS (VPD) ON GREENHOUSE TOMATO FRUIT QUALITY, FOLIAR NUTRIENT CONCENTRATION AND AMINO ACID COMPONENTS |
| Authors: | J. Lopez, M. Dorais, N. Tremblay, A. Gosselin |
| Keywords: | Lycopersicon esculentum, sulfate ions, vapor deficit presure regime, nutrient film technique, foliar composition, amino-acids |
| Abstract:
Nutrient solution recirculation is often used to improve the use efficiency of mineral nutrients and to reduce the contamination of soils and ground water. Nevertheless, in soilless culture systems, sulfate ions may accumulate in the nutrient solution recirculating resulting in nutrient imbalances affecting both crop yield and quality. This study focused the long-term effects of sulfate concentration and VPD regime on plant growth, fruit quality, foliar mineral concentration and amino acid contents. From day 10 after transplanting, young tomato plants (Lycopersicon esculentum Mill. cv Trust) grown in NFT system were subjected to three sulfate concentrations in the nutrient solution (in mM; S1=5.2, S2=10.4, and S4=20.8), and two VPD treatments (in kPa; H1= 0.5 day/0.4 night, H2= 0.3 day/0.2 night). In the short run and for both VPD, tomato plants appeared to be tolerant to a large spectrum of SO4 concentrations. After 7 months of sulfate treatments, however, high levels of SO4 in the nutrient solution resulted in reduced foliar and fruit Ca content. Over the long run, Ca-S interactions and blossom-end rot were found. Correlations between sulfate treatments and foliar accumulation of amino acid content were established. Osmotic adjustment and anion-cation balance of tomato plants grown under high sulfate supply and various VPD regime is discussed. | |
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