Summary:

In the years of 2003–2005 two-factors field experiment was set up in ES Lipnik near Stargard Szczeciński on the sandy soil (good rye complex) and a small retencion of usefulness water. The aim of the study was to determine the ef-fect of irrigation and mineral fertilization on the photosynthetic activity the leaves of some species of stone fruit trees. All experiments were done on the trees 4 years after planting. The experiments were designer by split-plot method in 7 replications with cherry, 5 replications with peach, and 4 replications with plum. Among the trees was the lawn but in the rows the selective herbicide fallow was kept. Two factors were considered: irrigation (O – control, W –under – crown ir-rigation) and mineral fertilization for cherry and plum 0 NPK – control (without fertilization), 1 NPK – 130 kg NPK•ha-1, 2 NPK – 260 kg NPK•ha-1; and for peach 0 NPK – control (without fertilization), 1 NPK – 150 kg NPK•ha-1, 2 NPK – 300 kg NPK•ha-1. Measurements of cherry, peach and plum leaves photosynthesis were done on well developer leaves on one year old branches. On basic of obtained results was found that photosynthetic activity of cherry peach and plum leaves was higher in the leaves from irrigated plants. Supplemental irrigation also increased CO2 concentration in stomata cells and also diffusion conductivity of stomata. Yielding of tested species on the irrigated and fertilized fields were higher. Fertilization and irrigation factor higher photosynthesis processes in plants. On the fertilized plots intensity of CO2 assimilation in the leaves of plum and peach significantly increased and also transpiration in plum and cherry leaves. Yields of fruit on the irrigated and fertilized plots were significantly higher comparing to those cultivated in natural conditions.