ESTABLISHMENT, GROWTH, AND FOLIAR NUTRIENT CONTENT OF PLUM TREES ON VARIOUS ROOTSTOCKS

The dwarfing characteristics of St. Julien and Pixy rootstocks, measured by shoot growth, were evident with 'AU-Amber' and 'AU-Producer' plum (Prunus salicina Lindl.) scions. Dwarfing did not occur with 'AU-Rubrum'. Trunk cross-sectional area (TCA) was reduced with 'AU-Amber', 'AU-Producer', and 'AU-Rubrum' scions on St. Julien and Pixy rootstocks. After 3 years, tree survival was 94% for Lovell; 89%, Halford; 57%, Nemaguard; 75%, Nemared; 83%, St. Julien; and 47%, Pixy. Tree survivability was significantly lower on Nemaguard and Pixy rootstocks than on Lovell and Halford. Multiple regression of total shoot growth, TCA, and survivability against foliar nutrient content resulted in the following significant equations: 0,460Mg - 0.210Mn, 0,236B - 0,487Mn, and 0,359N + 0.398Ca - 0,267P - 0,360Fe for each, respectively. Growth, survivability, and foliar nutrient content are significantly affected by rootstock in plum production.