Summary:

A field experiment was conducted in 2003 and 2005 at the Experimental Station Lipnik on acid brown soil. The soil is classified as quality class IVb, good rye complex, and for cultivation of light soils with low water retention useful. Evaluated the use of water for plum grown under different water and fertilizer. The experiment was randomized block design in the system dependent (called a split-plot), in four replications in the experiment. The research was conducted on trees in the fourth year after planting, fall within the third year of fruiting. Maintained grass between the trees, and rows of trees - herbicide fallow. The factor first was watering under-crown: O-control (without irrigation),W-irrigated sites, where soil water potential fell below - 0.01 MPa. Irrigation system was used under-crown in which water was distributed by type of Hadar. Second factor was the mineral fertilization NPK 0 - control (without fertilization), 2 NPK - 260 kg NPK. ha-1 (80 +60 +120).Nitrogen fertilizers applied in early spring, before moving the vegetation, while phosphorus and potassium in the autumn according to the agrotechnical. Based on water intensity ratio of photosynthesis to transpiration and photosynthetic rate were determined using (WUE) and photosynthetic rate of the instantaneous water use (WUEI).
Factors used in the experiment - supplementary irrigation and mineral fertilization - differentiated the values of the studies traits. Both the coefficient of efficiency (WUE) and (WUEI) used depended on irrigation, fertilization and me-teorological conditions over the study period. The leaves of plants fertilized cha-racterized by greater efficiency of water use.