INFLUENCE OF PRUNING SEVERITY ON FRUIT SIZE OF ‘SWEETHEART’, ‘LAPINS’ AND ‘HEDELFINGEN’ SWEET CHERRY GROWN ON GISELA ROOTSTOCKS

The effect of pruning as a crop regulation strategy to improve fruit size of the self fertile cherry cultivars, ‘Sweetheart’ and ‘Lapins’ or the non-self fertile cultivar ‘Hedelfingen’ was evaluated at Geneva, NY, USA in 2008 and 2009. Whole tree pruning treatments were applied to mature ‘Sweetheart’ in 2008 and to both ‘Sweetheart’ and ‘Lapins’ in 2009 on Gisela 5 and 6 rootstocks trained to either the Vertical Axis or Central Leader systems at bud swell in the spring.
Pruning treatments were applied to mature ‘Hedelfingen’ on 14 rootstocks in 2009. Treatments consisted of light pruning (control), removal of short shoots with less than 25cm growth, spur extinction (removal of 30% of the spurs), heading back of all fruiting branches by 30% and the combination of spur extinction pruning plus removal of short shoots with less than 25 cm growth.
The greatest increase in leaf to fruit ratio was with the spur extinction treatment and the combination of spur extinction plus removal of short shoots treatment.
Fruit size was increased most by spur extinction and the combina¬tion of spur extinction pruning plus the removal of short shoots.
Fruit size was highly dependant on crop load and leaf area per fruit.
With ‘Hedelfingen’ there were large differences in fruit size among rootstocks.
The relationship of leaf area:fruit ratio and fruit size was different for rootstocks which produce small fruit size than those that produce large fruits regardless of crop load indicating that the problem with small fruit size of some stocks cannot be solved solely by crop load adjustment.

VI International Cherry Symposium

T.L. Robinson, G. Bujdoso, G. Reginato

Prunus avium, yield, crop load, leaf:fruit ratio, fruit soluble solids, crop value

https://doi.org/10.17660/ActaHortic.2014.1020.61