SCHEDULING PRIMOCANE FRUITING RASPBERRIES FOR YEAR-ROUND PRODUCTION IN GREENHOUSES
In Ontario, raspberries have the potential to be grown year-round in greenhouses. Initial research has shown that primocane-fruiting raspberries can fruit for several years without a cold period, although in the winter production ceased. Since primocane raspberries can also fruit on overwintered canes, two experiments, one in 1998 and one in 1999, were set up to schedule fruit production throughout the year. In the first experiment, potted plants of Autumn Britten, Heritage, Polana and Summit were grown in the greenhouse and in the first year, plants either had their canes cut to 30cm, cut to the surface or left uncut. In December the plants were either left in the greenhouse or subjected to 6 weeks below 7°C. In the second experiment the treatments were the similar except that only Autumn Britten, and Polana were used and the cut to the surface treatment omitted. In the first experiment, all the plants cut to the surface died and in the first year, and the other treatments had similar yields. In the second experiment, plants with canes cut to 30 cm yielded less than the uncut plants. In both experiments, the plants cut to 30cm produced about one month later. In the second year, in both experiments the plants that had been chilled, fruited sequentially on their floricanes and primocanes from late March onwards. Those plants that were not chilled fruited on their primocanes from May onwards and had lower annual yields than those that were chilled. These results indicate that primocane -fruiting cultivars can be manipulated to fruit throughout most of the year, so fewer plants are needed compared to production systems which use floricane cultivars.
Dale, A., Sample, A. and King, E.M. (2003). SCHEDULING PRIMOCANE FRUITING RASPBERRIES FOR YEAR-ROUND PRODUCTION IN GREENHOUSES. Acta Hortic. 626, 219-223
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