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 (y_soil), stem water potential (y_stem), photosynthesis (Phot), transpiration (Tr) and stomatal conductance(g_s) in conditions of lysimeters on alluvial soil (Fluvisol) were studied. It was found that the physiological markers achieved their maximum values at y_soil » -10kPa. At y_soil = -15kPa a reduction of the respective quantitative parameters begun. At y_soil under -20-25kPa the inhibition of the studied physiological processes was appreciable.
A disturbance in the water balance of the plants occurred at a value of y_soil under -15kPa (y_stem = -1.25 MPa). At y_soil under -20-25 kPa the trees suffered a moderate to pronounced water stress (y_stem ³ -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