Summer pruning of early-maturing Prunus persica: Water implications

Abstract

Summer pruning (SP) in fruit trees can be performed with the aim of improving fruit quality by permitting better light penetration and carbon allocation, reducing the needs for winter pruning (WP). This paper deals with the effects of SP on the plant water status, vegetative growth, yield and fruit quality of two Prunus persica fruit trees of different ages: mature (peach trees) and young (nectarine trees). Pruning provided a total of 8 and 12 kg dry matter tree−1, being the SP contribution of 56% and 34%, of young and mature Prunus trees, respectively. Tree cover (obtained with zenithal image analysis) was significantly lower in the SP treatment, which resulted in an improvement in the plant water status of about 0.30 MPa with respect to WP trees in summer, leading to a reduction in water consumption during periods of highest evaporative demand (postharvest), equivalent to 10% of annual requirements under WP conditions. No significant differences were detected between WP and SP in the yield components studied. Our findings highlight the importance of considering the tree age/size as a key factor for the application of SP in trees grown under commercial conditions. Summer pruning can be considered a sensible cultural practice to mitigate the drought effects in early-maturing Prunus persica, maintaining yield with no extra costs.