Effect of Crown Restriction on the Growth and Productivity of Sweet Cherries

The canopy of sweet cherry trees grown under cover has to be adapted to this growing system by canopy lowering, narrowing and renewing. Tree growth and productivity parameters were compared three years before and three years after canopy restriction (2006-2011) for cultivars ‘Iputj’ and ‘Krupnoplodnaya’ on rootstocks Gisela 4 and 5, Weiroot 154 and F 12/1 during the full production period. The largest trees with wider canopy both before and after canopy restriction were observed on rootstock F 12/1. Limiting pruning of trees on Weiroot 154 did not cause stronger shoot growth. On Weiroot 154 the canopy was slightly bigger than for trees on Gisela 4 and 5. Canopy volume was bigger for ‘Iputj’ before adaptation to the cover system than for ‘Krupnoplodnaya’. After canopy reduction the fruiting wood renewed slowly, and therefore, yield per tree even in the third year after pruning was almost three times less than before pruning. As cultivar ‘Krupnoplodnaya’ renewed fruiting wood faster, it was 5-37% more productive than ‘Iputj’. Productivity renewed more rapidly for trees on dwarfing rootstocks, especially on Gisela 5. The fruits of cultivar ‘Krupnoplodnaya’ were bigger both before and after pruning compared with ‘Iputj’. Of the tested rootstocks, F 12/1 was found to be not suitable for plantations under cover.