WATER STRESS DETECTION IN GRAFTED AND NON-GRAFTED GREENHOUSE TOMATO PLANTS BY CHLOROPHYLL FLUORESCENCE PARAMETERS

In order to study the effect of water stress on chlorophyll (Chl.) fluorescence parameters in greenhouse tomato (Lycopersicon esculentum Mill.), three types of cv.
Trust plants (T, non grafted plants; TE, plants grafted on Eldorado rootstock; Tm, plants grafted on Maxifort rootstock), and three growing systems (1- rockwool slab, 2- sawdust bucket, 3- sawdust bucket equipped with a capillary system) were compared within a greenhouse split plot design with three replicates of 180 plants.
Suboptimal water supply decreased the matric potential of growing media and could to some extent be detected by the determination of chlorophyll fluorescence parameters.
Increasing water stress resulted in increasing F₀ and reducing of F_m in all growing systems, and then reduced F_v and F_v/F_m ratio.
The use of capillary system resulted in an increase in water retention of sawdust and in plant water use.
Tomato plants grown in the capillary growing system showed less fluctuation in Chl fluorescence parameters such as F_v/F_m ratio than those grown in sawdust without a capillary system.
Under suboptimal water supply, grafted plants showed better Chl fluorescence parameters, such as higher F_v/F_m ratio, than none grafted plants.
On the other hand, under moderate water stress, the use of F_v/F_m as a stress indicator was less valuable and other Chl fluorescence parameters should be used together.
The possibility of using Chl fluorescence parameters for evaluating water stress status of greenhouse tomato plants and managing irrigation is discussed.

International Symposium on Strategies Towards Sustainability of Protected Cultivation in Mild Winter Climate

M. Delshad, A.K. Kashi, M. Babalar, M. Dorais, A. Gosselin

water deficiency, rootstock, grafting, matric potential, growing medium

https://doi.org/10.17660/ActaHortic.2009.807.96