THE POSSIBILITY OF APPLYING REGULATED DEFICIT IRRIGATION TO PEACH ORCHARDS IN THE EMILIA-ROMAGNA REGION

Regulated deficit irrigation (RDI) is a technique which permits the control of peach tree growth and fructification in arid environments with considerable water saving and without any adverse effects on fruit size and yield. The RDI technique was simulated on the basis of daily climatic data covering a period of thirty years for the subhumid Emilia-Romagna Region. The daily water balance was calculated for three peach-growing areas and for three cultivars maturing in different periods and grown in different types of soil. Findings showed that affecting plant growth by limiting water availability in early-season cultivars was possible only in the post-harvest stage, while in late-season cultivars the effect was greater during the rapid growth stage (i.e. during F2), and less pronounced during the post-harvest stage. Medium-season peach cultivars were found to be affected by RDI in both pre - and post-harvest stages; this however only occurred in a limited number of years and especially in coarse and grass mulched soils. Water saving was potentially high under all conditions.