Possibilities for Water Status Evaluation of Young Cherry Trees (Prunus avium L.) on Clonal Rootstock GM9 by Means of Some Physiological Markers

D. DOCHEV1, V. DJOUVINOV1, M. GOSPODINOVA1, K. KOLEV1, Ph. BOXUS2, V. KERIN3, Z. ZLATEV3, N. VICHEV4, I. KIRKOVA4 and G. STOIMENOV4
1 Research Institute of Fruit Growing , BG-4004 Plovdiv, Bulgaria
2 Centre of Agricultural Research, Dept. Biotechnology, B-5030 Gembloux, Belgium
3 Agrarian University, BG-4000 Plovdiv, Bulgaria
4 "N. Poushkarov" Institute of Soil Science, BG-1311 Sofia, Bulgaria

Abstract

DOCHEV, D., V. DJOUVINOV, M. GOSPODINOVA, K. KOLEV, Ph. BOXUS , V. KERIN, Z. ZLATEV, N. VICHEV, I. KIRKOVA and G. STOIMENOV, 2001. Possibilities for water status evaluation of young cherry trees (Prunus avium L.) on clonal rootstock GM9 by means of some physiological markers. Bulg. J. Agric. Sci., 7: 207-211

The relations between soil water potential (ψsoil), stem water potential (ψstem), photosynthesis (Phot), transpiration (Tr) and stomatal conductance(gs) in conditions of lysimeters on alluvial soil (Fluvisol) were studied. It was found that the physiological markers achieved their maximum values at ψsoil ≈ -10 kPa. At ψsoil = -15kPa a reduction of the respective quantitative parameters begun. At ψsoil under -20-25 kPa the inhibition of the studied physiological processes was appreciable.
A disturbance in the water balance of the plants occurred at a value of ψsoil under -15 kPa (ψstem = -1.25 MPa). At ψsoil under -20-25 kPa the trees suffered a moderate to pronounced water stress (ψstem ≥ -1.4-1.5 MPa). These values seem to be appropriate for a physiologically based management of the irrigation regime.

Key words: cherry, lysimeters, irrigation (RDI), water stress indicators