Genetically diverse peach seedling rootstocks affect long-term performance of 'Redhaven' peach on fox sand

Ten genetically diverse peach [Prunus persica (L.) Batsch] seedling rootstocks were studied for 10 years on Fox sand using 'Redhaven' as the scion. The purpose of the experiment was to assess the performance of three Harrow Research Station (Ont.) hybrid selections (H7338013, H7338016, and H7338019) and two northern China introductions ('Chui Lum Tao' and 'Tzim Pee Tao') against five commercial standards, two of which were selected in Canada ('Harrow Blood' and 'Siberian C') and three in the United States ('Bailey', 'Halford', and 'Lovell'). Rootstock performance was assessed indirectly by measuring or subjectively rating various aspects of scion performance including annual trunk cross-sectional area (TCA); final tree height, spread, and TCA; bloom and fruit set intensity; yield and yield efficiency; canker (Leucostoma spp.) severity; defoliation rate; winter injury; cold hardiness of flower buds and shoot xylem; and tree survival. Rootstock effects on the above measurements and ratings were significant in some years and not in others. Year effects were always large and significant, while rootstock X year interactions were usually small and not significant. In the combined analyses over years, the largest rootstock effects were obtained for bloom, fruit set, and defoliation ratings and for TCA measurements. Three cumulative responses, including marketable yields, yield efficiency, and tree survival, were used for comparing the five experimental rootstocks with the five commercial standards and also for ranking the 10 rootstocks with respect to each other to assess their potential commercial value as peach rootstocks. 'Chui Lum Tao', H7338013, and 'Bailey' had the most commercial potential for southern Ontario because they typically promoted above average cumulative yield, yield efficiency, and tree survival. 'Tzim Pee Tao', 'Siberian C', and 'Harrow Blood' were less valuable, with low cumulative marketable yields.