Water requirements in traditional plum producing regions of Serbia

Plum water requirements are relatively large. European plum cultivars (Prunus domestica L.) produce best yields in regions with annual precipitation above 700 mm and vegetation seasonal rainfall above 350 mm. Increased climate variability, as a consequence of climate change, has brought interannual redistribution of precipitation, more frequents droughts and intensive precipitation. Main goal of this research was to analyse water requirements of plums in order to support producers in decision-making towards achieving high quality yields. Plum water requirements were analysed in nine administrative regions across western, southern and central Serbia, where more than 90% of its production is situated. Based on observed meteorological data for the period 2000-2019 mean seasonal evapotranspiration and water deficit for the plum orchards with and without grass cover were calculated. The smallest mean seasonal deficit is found in the Zlatibor region (285.3 mm with, and 131 mm without grass cover) and the largest in Pomoravlje region (615.4 mm with, and 411.3 mm without grass cover). The largest monthly deficit in all studied regions is found in July, a month of peak water consumption in the Serbia's climate conditions. Although both evapotranspiration and water deficit are larger in case of orchards with grass cover, grassing in regions with sufficient precipitation creates favourable microclimatic conditions in orchards, which has positive effect on the quality of fruits, as well as protects the soil from erosion (degradation).