Browsing by Author "Vennelä, Tanja"

Strawberry (Fragaria × ananassa Duch.) is both quantitative and economically most important cultivated berry in Finland. The problem in Finland is low crop yield and short harvest season. During the main season the high supply lower radically the price. The price is highest before and after the main season. Production with everbearing strawberries would give long and even harvest season with more stable price. Everbearing strawberries suit well for table-top production in polythene tunnels with drip irrigation and fertilization. Everbearing strawberries produce flowers and berries during the whole season which affects the nutrient demand. Three different electrical conductivities in the nutrient solution, 1,5 mS/cm, 2,3mS/cm and 3,0 mS/cm, with N:K –ratio 1:1,5 during the ripening, was investigated. The fourth electrical conductivity was 2,3 mS/cm with N:K –ratio 1:2 during the ripening. The vegetative growth, crop yield and quality was evaluated. The amount of drainage water was measures and the amounts of leached nitrogen and phosphorus was analysed. The varieties in the study were ‘Malling Opal’ and ‘Rondo’. Like in previous studies the nutrient demand of strawberry is relatively low. Strongest vegetative growth, highest yield and largest berries was observed with the lowest (1,5 mS/cm) nutrient level. The nutrient level had very little effect on the fruit quality or starting time of the harvest season. The change in the N:K -ratio during ripening did not affect the fruit quality. The uptake of water was highest in the nutrient solution with lowest electrical conductivity. The problem with the water uptake with high electrical conductivity was probably caused by the high ion content in the nutrient solution. The amounts of nitrogen and phosphorus increased significantly in the leaching water with increasing electrical conductivity in the nutrient slution.