Pruning strategy affects fruit size, yield and biennial bearing of 'Gala' and 'Honeycrisp' apples
Field studies were conducted at Geneva, NY, USA over three years using mature 'Gala' and 'Honeycrisp' apple trees on M.9 rootstock. We compared three styles of pruning. The most aggressive pruning treatment consisted of the elimination of 1-3 branches completely and then cutting back all of the remaining fruiting branches or shoots on the tree by 1/3 (stubbing back). A second treatment consisted of the elimination of 1-3 branches completely and then the elimination of 1/3 of all fruiting spurs (spur pruning or spur extinction). A third treatment consisted of the elimination of 1-3 branches completely but no detail pruning (minimal pruning). The stubbing back treatment and the spur extinction pruning reduced flower bud load, fruit number and yield the most but increased fruit size and crop value compared to minimal pruning. The effects of pruning were largely related to their effects on crop load. Return bloom of 'Honeycrisp' was not largely affected by pruning method however, pruning treatments that allowed for resting buds had better return bloom than either spur extinction or stubbing back.
Robinson, T.L., Dominguez, L.I. and Acosta, F. (2016). Pruning strategy affects fruit size, yield and biennial bearing of 'Gala' and 'Honeycrisp' apples. Acta Hortic. 1130, 257-264
Malus × domestica, spur extinction pruning, stubbing back pruning, renewal pruning, crop value, return bloom