Performance of Russian Primocane Fruiting Red Raspberry Cultivars in Latvia

The interest in growing of primocane fruiting raspberry cultivars is increasing in Latvia due to the possibility to extend the production season and diminished problems with pests and cane diseases. Many primocane fruiting cultivars with late production times are not appropriate for growing in Latvia in open fields because of climatic conditions where often early autumn frosts are observed. It is therefore essential to find well adapted cultivars with an early autumn production time. The evaluation of three primocane fruiting red raspberry cultivars of Russian origin - 'Babye Leto', 'Babye Leto-2' and 'Gerakl' - was performed at the Pure Horticultural Research Centre during 2006-2010. Raspberries were planted in October 2004, in rows 0.5x2.7 m apart. A split plot trial design was used, where 11 plants per plot were planted in 4 replicates. Each cultivar was cultivated for double production (summer and autumn crop) and for a single autumn crop. For double cropping, topping of production canes and removal of dead canes were done. For a single autumn crop, all canes were pruned at ground level every year after fruit harvesting. Vegetative growth, phenology, incidence of pests and diseases, productivity and fruit quality were evaluated. Results showed a good adaptability of all tested cultivars to climatic conditions of the region. The highest total yield was harvested from cultivars 'Babye Leto-2' and 'Gerakl'. However 'Babye Leto-2' had a high percentage of crumbly fruits, caused by infection with Raspberry Bushy Dwarf Virus (RBDV). 'Gerakl' had the highest marketable yield and the largest fruits between tested cultivars. Double production cultivation was not found as effective for the evaluated cultivars, as the obtained summer yield was low. Use of double production also increased the incidence of cane spot disease.