Blueberry water loss is related to both cuticular wax composition and stem scar size

The contributions of the cuticle and stem scar to blueberry water loss were evaluated in four cultivars. Among the cultivars, 55–69% of the water loss occurred through the cuticle, indicating the key role of the cuticle and cuticular waxes in restricting water loss. Cuticular wax content at harvest ranged from 38.12 to 67.00 μg cm−2 across the four cultivars and increased during four-week postharvest storage by an average of 49.5%. Oleanolic and ursolic acid were the most abundant wax compounds. The amount and proportion of oleanolic acid were negatively related to water loss. Wax esters were at low levels in all cultivars, but their content and proportion were directly related to water loss. The stem scar size was directly related to water loss, but only within a given cultivar and not across cultivars. This study provided new knowledge on the role of the cuticular waxes and stem scar in determining water loss in blueberries.