The Influence of Crop Density on Annual Trunk Growth of ‘Golden Delicious’ Apple Trees on Three Rootstocks at 11 Locations
Journal of the American Pomological Society
‘Golden Delicious’ apple trees [Malus x domestica (Borkh.) on three dwarfing rootstocks were grown at 11 locations in North America, and crops were adjusted to varying levels of crop density to determine if rootstock influenced the relationship between crop density and annual trunk growth over a 5-year period. Analysis of covariance was used to evaluate both separate and interactive effects of crop density and rootstock on annual trunk growth. In most cases there was a negative linear relationship between crop density and trunk enlargement. There was rarely a significant interaction between rootstock and crop density, indicating that the suppression of trunk growth by cropping was similar for all rootstocks. Regardless of crop density, trees on M.26 EMLA generally exhibited the most annual trunk enlargement, trees on G.16 exhibited the least trunk enlargement, and trees on M.9 NAKBT337 were intermediate.
Marini, R.P., W.R. Autio, B. Black, J. Cline, R.M. Crassweller, P.A. Domoto, C. Hampson, R. Moran, R.A. Quezada, M. Stasiak, T. Robinson, D. Wolfe. 2012. The Influence of Crop Density on Annual Trunk Growth of ‘Golden Delicious’ Apple Trees on Three Rootstocks at 11 Locations. Journal of the American Pomological Society. Journal of the American Pomological Society 66(4): 183-195.