An innovative formulation to increase the thinning strategies’ efficacy

‘Fuji’ is considered a cultivar “difficult to thin” and difficult to manage. Often, the fruit thinning operation is performed using different active ingredients applied in sequence. This technique is called “strategy” and is frequently used in the practice on the “difficult to thin” cultivar to reach the desired yield and fruit quality at harvest. In this work, the following aspects were considered: i) the possibility of chemically inducing the corymb hierarchy; ii) evaluate the thinning efficacy of two chemical agents (6-BA and Metamitron) applied alone or in sequence on two apple cultivars considered “easy” and “difficult to thin”. The PS148DG did not significantly affect the hierarchy of the corymb but the trees treated subsequently sprayed with the different thinning agents always achieved higher fruit drop values as compared to the untreated control trees. The fruits of the trees treated with PS148DG alone also reached higher yield and fruit weight and color.