ISHS Acta Horticulturae 761: XXVII International Horticultural Congress - IHC2006: International Symposium on Advances in Environmental Control, Automation and Cultivation Systems for Sustainable, High-Quality Crop Production under Protected Cultivation
EFFECT OF AMBIENT HUMIDITY ON PHYSIOLOGICAL ACTIVITIES AND FRUIT YIELD AND QUALITY OF GREENHOUSE TOMATO |
| Authors: | H.-L. Xu, D. Iraqi, A. Gosselin |
| Keywords: | fruit quality, greenhouse tomato, humidity, photosynthesis, rubisco |
| Abstract:
Air humidity is an important factor that affects greenhouse tomato growth and physiology in many aspects. We examined effects of different humidity regimes in greenhouse on tomato growth, photosynthesis, fruit yield and quality and other related physiological activities. Plants grown under high VPD (low air humidity) showed a higher photosynthetic capacity (PC) than plants grown under a low VPD (high air humidity). The differences in PC between humidity treatments were larger in early stage (winter time) than in later stage (spring time). Leaf turgor potential did not show differences between treatments although leaf water potential was slightly lower in plants grown under high VPD than that in plants grown under low VPD. Chlorophyll content, chlorophyll a/b ratio, soluble protein content and activities of rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) were higher in plants grown under high VPD than those grown under low VPD. These might be the accounts for high PC in plants grown under high VPD. Fruit yield was higher for plants grown under high VPD than for plants grown under low VPD. High VPD resulted in a better fruit quality shown by the texture, color, and sugar content. Osmotic potential was lower and the osmotic solute concentration was higher in low humidity, which is accountable for leaf turgor maintenance under low humidity conditions. Our results suggested that a relatively low humidity should be maintained to obtain high physiological activities and the consequent high fruit yield and quality. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
