Effect of a Rapid Water Stress and a Slow Water Stress on the Growth of ‘Redhaven’ Peach Trees 1

Abstract

A rapid water stress (RWS) and recovery treatment and two levels of a slow water stress (SWS) treatment (rewatering at 50 and 25% of control water use) were applied to one-year-old peach trees ( Prunus persica, L., Batsch, cv. ‘Redhaven’/‘Halford’) under greenhouse conditions. Growth, growth rates, leaf water potential components, and stomatal conductance were observed. Occurrence of statistical differences between treatments was used to determine sensitivity to stress. Total leaf water potential was 0.18MPa less than control for the stress trees after one week of RWS. Leaf emergence was more sensitive than leaf or shoot growth; however, leaf growth rates recovered first after rewatering. Leaf emergence, leaf length, and shoot length were reduced by 80, 77, and 65% respectively. Available soil water declined to 40 and 20% of the control for the 50 and 25% SWS treatments. Leaf emergence, leaf growth, shoot extension, and trunk diameter were reduced by 58, 82, 56, 76, and 64% for the 50% treatment, and 50, 75, 36, 57, and 39% for the 25% treatment, respectively. Significant reductions in stomatal conductance followed with the reductions in growth within 2-7 days for the SWS experiment.