PRUNUS ROOTSTOCKS AFFECT LONG-TERM ORCHARD PERFORMANCE OF REDHAVEN PEACH ON BROOKSTON CLAY LOAM

Performance of 'Redhaven' peach [Prunus persica (L.) Batsch.] propagat ed on nine experimental Prunus rootstocks was evaluated over 8 years b eginning in 1984, in a randomized complete-block experiment with 10 re plications on a Brookston clay loam soil type near Harrow, Ont. This e xperiment was part of an interregional NC-140 peach rootstock experime nt. Significant rootstock-induced effects were noted for increase in t runk cross-sectional area, cumulative tree height and spread, cumulati ve number of root suckers, yield, average fruit weight, yield efficien cy, winter injury, cold hardiness, and tree survival. None of the clon ally propagated rootstocks gave satisfactory overall performance. All trees on GF655-2,80 % on GF677, 60 % Self-rooted, and 50 % on GF1869 w ere dead by the eighth year. In addition, suckering was a major proble m on GF1869 and a moderate problem on GF655-2. 'Citation' induced the most scion dwarfing but had the lowest yields and low yield efficiency . When yield, yield efficiency, fruit size, and tree mortality were co nsidered together, the four peach seedling rootstocks performed better than the other Prunus rootstocks and were ranked as follows: Siberian C, Halford, Bailey, and Lovell. Of these, the first three could be re commended with the most confidence to commercial growers who grow peac hes on fine-textured soils in northern regions.