APPLICATIONS OF XEROPHYTOPHYSIOLOGY IN PLANT PRODUCTION - TOMATO FRUIT YIELD AND QUALITY IMPROVED BY RESTRICTED IRRIGATIONS IN SOIL-BASED GREENHOUSES

Autor: F.F. Qin, R. Wang, C.M. Tian, Q.C. Xu, H.L. Xu
Rok vydání: 2011
Předmět:
Zdroj: Acta Horticulturae. :987-996
ISSN: 2406-6168
0567-7572
Popis: Plant can perceive environment changes and adjust itself internally to get ready to resist the coming adverse conditions. In the present research, drip infiltration, a kind of deficit irrigation, was imposed to tomato plants. This deficit irrigation was perceived by the tomato plants as a false stimulus of drought and made the plants stronger by internal physiological adaptation, such as osmotic adjustment and symplastic water compartmenting. Tomato plants under infiltration irrigation showed a higher osmotic concentration or lower osmotic potential in symplasm at fully turgid status and a consequent higher leaf turgor potential. Leaf symplastic water fraction was larger or apoplastic water fraction was smaller in tomato leaves under infiltration irrigation. Both osmotic potential and relative water content at the point of incipient plasmolysis were lower in tomato leaves under infiltration irrigation, suggesting a higher resistance to water stress. The higher leaf turgor potential and the larger symplastic water fraction might have supported the higher leaf photosynthesis in the treated plants. Soil microbial activities were also improved by infiltration irrigation. In conclusion, horizontal infiltration irrigation can improve plant physiology and consequently increase tomato fruit yield. The higher physiological activities might be resulted from xerophytophysiological responses under unwet or modest dry conditions. INTRODUCTION Irrigation has developed from basin and furrow, through sprinkler, to drip and trickle irrigation (Masse, 1981). Drip or trickle irrigation has come into favor because it conserves water and plastic tubing makes the installation convenient (Adamsen, 1992). Efficient irrigation means applying enough water to prevent plant water deficits without surplus that drains below the root zone, in addition to improvements in crop yield and product quality. Sometimes irrigation must be controlled at a minimum sufficient level even if the water resource is plenty. For example, greenhouse production requires a dry air condition to prevent infection from fungus diseases and a modest drought in soil to obtain a good fruit quality (Xu at al., 2007). This kind of controlled irrigation is also called regulated deficit irrigation (RDI). As reported by Goodwin and Jerie (1992), RDI for fruit trees has increased water use efficiency by approximately 60% with no loss in yield. It is also useful for reducing excessive vegetative vigor and for minimizing nutrient loss through leaching. Chalmers et al. (1986) have reported higher yield and better quality a huilian@janis.or.jp b jialing_300@163.com Proc. IS on High Technology for Greenhouse Systems GreenSys2009
Databáze: OpenAIRE
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