Effects of Foliar Calcium Applications on Raspberry Fruit Quality and Shelf Life

Abstract—The current study investigates the effect of foliar calcium applications on fruit quality of 'Carmina' raspberry. The first product is a liquid fertilizer (CaO: 12%) applied in three doses: T1 (100 cc/hl), T2 (200 cc/hl) and T3 (400 cc/hl). The second product is Calcium Nitrate (CaO: 26.3%) used in a single dose T4 (230.8 g/hl). Data collected included fruit weight and caliber, rating of fruit colour, firmness, acidity, total soluble solids (TSS), and fruit weight loss during storage. Fruit and leaves were sampled to determine Ca concentration. Results show that foliar treatments had no significant effect on fruits average weight, nor their size. Treatments T2 and T3 significantly increased fruit firmness. Fruit TSS and acidity showed no significant differences from T0. Applications did not affect post-harvest fruit weight losses. Foliar application of calcium caused an increase in leaf calcium content of 46 and 42% respectively for T2 and T3, and an increase in fruit calcium content of 35 and 18% respectively for T2 and T3 compared to T0. There was no difference between the contents of leaves and fruits regarding the other elements (Mg, K, Fe, Mn, Zn and Cu). The right frequency of application is once every 8 days.