Transpiration and leaf growth of gladiolus in response to soil water deficit

Abstract

The objective of this study was to evaluate the response of transpiration and leaf growth of gladiolus cultivars to a drying soil represented by the FTSW. Three experiments (E1, E2 and E3) were individually carried out in 20 pots, with four gladiolus cultivars. Plants did not experienced water deficit until they had less than seven leaves in E1, four leaves in E2 and, four and seven leaves in E3. At these stages, water deficit was imposed in 10 pots of each experiment, while the other 10 pots remained without water deficit. The FTSW, transpiration and leaf growth were measured daily, during the period of water deficit. Results indicated that the threshold FTSW for transpiration is higher when water deficit occur during the reproductive phase. We concluded that the FTSW threshold for NTR in gladiolus varies depending on the developmental stage at which the water deficit is applied, being higher when it occurs during the reproductive phase and lower when it occurs during the vegetative phase. Water deficit reduces leaf appearance rate in gladiolus, delaying the harvesting point of the flower stems.