Effect of irrigation and fertilization methods on red raspberry winter survival

Factors increasing vegetative growth in the autumn have a negative effect on raspberry winter survival. Therefore, a closer study was initiated examining three different drip irrigation treatments, with irrigation thresholds - 150 hPa, - 300 hPa and - 600 hPa, and two fertilization methods, fertigation and fertilization with granular fertilizers, in the years 2001 - 2003 at MTT Horticulture, southwest Finland. Excessive irrigation weakened the winter survival of raspberry ( cv. `Jatsi') and the optimal irrigation threshold was - 600 hPa. Fertilization method had no remarkable effect on winter survival. On the basis of earlier research and the present study, it is recommended that heavy irrigation late in the growing season should be avoided.