Apricot Vegetative Growth, Tree Mortality, Productivity, Fruit Quality and Leaf Nutrient Composition as Affected by Myrobalan Rootstock and Blackthorn Inter-Stem

Abstract

The behavior of five apricots grafted across Blackthorn inter-stem (BI) on Myrobalan stock and on Myrobalan rootstock (MR) was evaluated through vegetative growth, tree mortality, productivity, fruit quality and leaf nutrient composition from the 1st to the 6th leaf. The trial was performed in the Prislonica village (Cacak, Serbia), on a dry, shallow, sandy-loam and acidic soil. Results showed that MR improved tree vigor, yield per tree, cumulative yield, fruit weight, flesh rate, acidity, antioxidant power, leaf N, K, Ca and Mn contents and better balanced nutritional values for macronutrients. BI increased tree mortality, yield efficiency, yield per hectare, total phenolic and total flavonoid contents, and leaf P and Fe amounts. Wide variability among cultivars for evaluated traits was observed on both BI and MR. The more vigorous trees had 'Biljana' as compared with others on both BI and MR, whereas the most productive cultivar was 'Vera' on BI and 'Biljana' on MR. The highest and similar fruit weight had 'Roxana' and 'Harcot', whereas the highest stone weight and flesh rate was found in 'Vera' and 'Harcot', respectively, all in both BI and MR. Fruits harvested from 'Aleksandar' trees were rich in soluble solids content (SSC), titratable acidity (TA) and total flavonoid content (TFC), 'Harcot' in total phenolic content (TPC), and 'Roxana' in acidity and total antioxidant capacity (TAC), also on both BI and MR. The better balanced nutritional values were promoted by BI. Regarding cultivars, the best balanced nutritional values for macronutrients were exhibited by 'Vera' on BI, and by 'Harcot' on MR. For micronutrients, the wider imbalance among nutrients was found in 'Roxana' on BI, and in 'Vera' on MR.