ISHS Acta Horticulturae 294: II Symposium on Horticultural Substrates and their Analysis, XXIII IHC
AIR HUMIDITY AND NUTRIENT CONCENTRATION AFFECT NUTRIENT UPTAKE AND GROWTH OF SOME GREENHOUSE PLANTS |
| Authors: | Hans R. Gislerød, Leiv M. Mortensen |
| Abstract:
Young plants of different species were grown at 60, 75 and 90% relative humidity in growth rooms. The dry weight increased significantly by increasing RH from low to high for Begonia (47%), Saintpaulia (17–36%), Euphorbia (31%), Chrysanthemum (31%), Nephrolepis (68%) and Lycopersicon (20%). The dry weight of Campanula, roses, cucumber and lettuce was not affected by RH. The shoot length and leaf area increased for most of the species by increasing air humidity. For some species the number of flowers was increased and time to flowering reduced. The transpiration rate decreased with around 50% by increasing the RH from 60 to 90%. The content of macro nutrient elements in the plant leaves decreased by raising RH. This decrease was significant for K, Ca and Mg in tomato, N in Nephrolepis, P in Begonia and K and Ca in Chrysanthemum. By increasing the concentration of the nutrient solution (1, 2 and 4 mS/cm) some reduction were found in B. x hiemalis in dry weight and elongation at both low and high RH. It was also a significant decrease in the leaves and stems for N, P and K with increasing RH. With increasing concentration of the nutrient solution given to the plants the content of N, P and K increased. It was also a significant interaction between RH and nutrient concentration. | |
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