Thick shoots of 6-8 buds long are selected during winter pruning for carrying fruit in the coming season. These shoots tend to have better flower bud development than weaker or stronger shoots. Winter pruning is required to reduce shoot competition for resources and light during the growing season. The size of the flower or calyx at flowering can influence fruit weight at harvest. The calyx is a source of natural growth hormones which promote fruit development and serves as a gas exchange organ for the developing fruit.
Small calyces can result in reduced fruit size at harvest.
However, in seasons with poor pollination and environmental stresses during the post-flowering period, fruit drop can interfere with the expected yields from early thinning. This is due to shading causing fruit temperatures to be lower than optimum for fruit growth. Exposing fruit to light can increase fruit temperature by 5-7 o C and subsequently improve fruit size. An open canopy is important to ensure adequate light exposure to the fruit. The presence of chlorophyll at harvest can mask the full colour of the carotenoids.