Effect of load regulation by winter pruning on fruit quality attributes of Duke and Legacy blueberry cultivars

Legacy and Duke are the main blueberry ( Vaccinium corymbosum L.) cultivars grown in Chile, with 32.8% of the total Chilean cultivated area with this fruit. The market demands fruit firmness, size, weight, and quality attributes, which are improved by some agronomic management practices such as winter pruning. The present study evaluated the effect on blueberry quality attributes and fruit yield of five fruit bud load levels, regulated by winter pruning during two consecutive seasons, on ʻLegacyʼ and ʻDukeʼ. The study was conducted in three commercial orchards under different soil conditions (Inceptisol, Andisol, and Entisol) in south-central Chile. Results indicated that there were differences in fruit load treatments between seasons, orchards, load levels, and week of harvest (first or second). Reducing the fruit bud load by winter pruning improved quality attributes of fruit firmness, size and weight, but negatively affected production per plant. We found in two seasons that pruning 60% of the fruit bud load level had the highest values for fruit firmness, size, and weight in both blueberry cultivars, but the production was 70% and 86% of the potential in ‘Duke’ and ‘Legacy’, respectively.