Evaluation of Brevis® as a thinning agent for ‘Fuji’

The present research deals with the evaluation of the thinning efficacy induced by Brevis® on Fuji apple. Brevis® was tested at different concentrations and times of application in order to establish the most appropriate treatment in terms of thinning efficacy and to avoid the risk of over-thinning. All tested chemical combinations induced similar or higher thinning values than the untreated control. Expected level of yield similar to hand thinned trees, were obtained with the highest concentration of Brevis® applied alone or in a repeated application. The thinning results were partially explained with the climatic conditions of the location where the trial was carried out and with the chlorophyll fluorescence value detected with an innovative device, the BPS-meter, used for evaluating the photosystem II inhibition caused by the chemical itself. These circumstances were considered in a model system created by a dedicated Working Group led by ADAMA that forecast the efficacy of the Brevis® a lication as related to climate and fruit size.