ISHS Acta Horticulturae 649: Euro Berry Symposium - Cost 836 Final Workshop
SUMMER PRUNING EFFECT ON REPRODUCTIVE YIELD COMPONENTS OF 'TRIPLE CROWN' BLACKBERRY |
| Authors: | P.B. Oliveira, L. Lopes-da-Fonseca, D.L. Jennings |
| Keywords: | Rubus sp., out-of-season, non-heated greenhouse |
| Abstract:
Off-season fruit production in southern Europe is profitable when low-input production techniques are available. Late blackberry production in southern Britain is often achieved by spring pruning the laterals and summer pruning of the primocanes is commonly used to induce late production from primocane-fruiting raspberries in Portugal. In order to delay the production of 'Triple Crown' blackberry grown under plastic, experiments were done to determine the influence of the date of lateral pruning and its intensity. Laterals were cut back to two nodes on three dates (18 April, 2 May and 16 May) and to four nodes on one date (16 May) with a control treatment (not pruned). For each treatment the yields were recorded for two laterals each from the top, middle and bottom zones of four canes and compared to the yields of laterals from untreated canes. Cropping was delayed by more than two months for all pruning dates, but both yield per plant and per cane were reduced by the later pruning dates, because fruit numbers were lower. Lateral vigour in the top and middle zones was much reduced but the vigour and yield of the bottom laterals was not affected. Laterals pruned to four nodes on May 16 gave the lowest yield and the shortest harvest period. Although the technique was labour intensive, it considerably reduced yields and quality. Profitability for blackberries during September and October will depend on market prices. Other cultivars must be tested, especially those whose canes are productive in the lower zones and whose fruits ripen easily. | |
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