Improving the performance of red and white currants in high latitude conditions by training methods

S. Karhu, C. Bles, K. Laine, P. Palonen
Red and white currants (Ribes rubrum group) are most often grown in a bush training system in the northern European countries. We studied fruit production of red and white currant cultivars in northern Europe in three different trials by training the plants on wires as cordons. When red currants grown before in bush form in open field were converted to cordon system, their yield was reduced to be in the first year on average 38% and in the second year 61% of the yield of bush-form plants. When, however, a biennial pruning system by retaining previous-year yielding branches in addition to new ones was used, the yield of cordon plants exceeded that of bush-form plants. Fruit size was also improved by 36% while the number of berries per raceme was unaffected. The cultivar 'Punahilkka' produced longest racemes with a high number of berries, making it the most suitable for fresh fruit marketing. The biennial pruning method was compared to annual-shoot pruning method in two red currant cultivars planted in a cordon training system in a high polytunnel. The biennial method resulted in the yield increase of 130% in one cultivar but only 31% in another cultivar. Berries of long side branches were larger than those developed on main trunks in shortened fruiting spurs. Two white currant cultivars were grown as cordons with different number of annual cropping side branches. A larger proportion of total crop was produced in long side shoots in 'Lepaan Valkea' than in 'Piikkiön Helmi'. Increasing the number of long annual side shoots higher than five per main trunk improved the yield of that cultivar.
Karhu, S., Bles, C., Laine, K. and Palonen, P. (2020). Improving the performance of red and white currants in high latitude conditions by training methods. Acta Hortic. 1277, 225-232
DOI: 10.17660/ActaHortic.2020.1277.32
fresh fruit, cordon, pruning, Ribes, trellising

Acta Horticulturae