Effects of 19 rootstocks on the performance of 'Imperial Gala' grown in the V System.

摘要

Intensive orchard management systems utilizing dwarfing rootstocks has now become common place as a standard practice in North America for apple production. Growers in North America are increasingly becoming aware of the relationship between plant density and production. Growing trees in a V shape can achieve the goal of increased plant density with minimum inhibition to light penetration into the canopy. A trial was established in 1993 at the Clarksville Horticultural Experiment Station, Clarksville, Michigan, USA with cultivar Imperial Gala planted on 19 rootstocks in a split plot design with main plots established and grown in the Guttingen V and V trellis wire system. All trees were planted at 0.75 x 4.0 m, representing a density of 3320 treesper ha. Trees were trained as slender spindle and leaned to 20 degrees from the vertical, alternating direction along the row. The sub-plots within the system were tested and compared with the performance of 19 rootstocks, including Mark, Bud.9, M.9, M.9 EMLA, Vineland 605-1, Vineland 605-3, P.2, P.22, M.9 NAKB 337, M.9 NAKB 338, M.9 NAKB 339*, M.9 NAKB 340, M.9 Janssen NAKB 337, RN 29, MAC 39, CG 10, Burgmer 751, Burgmer 756 and Burgmer 984. There were no significant differences in most performance characteristics between the two orchard systems. Cropping over the trial period was not significantly different among the top 14 rootstocks. The rootstocks that ranked among the top 5 in production include M.9 NAKB 340 (sister clone of NAKB 337), Burgmer 984 (M.9 clone from Germany), Mark, Bud.9 and Burgmer 751. The bottom 4 rootstocks in cumulative yield since 1993 include V.1, P.22, CG.10 and Mac 39.