Economic benefit of an optimized copper spray program for citrus canker and black spot control in Brazil

ABSTRACT Copper-based formulations are used extensively to manage two of the leading citrus diseases that affect the São Paulo (SP) citrus belt, Brazil, namely, citrus canker and citrus black spot. Since the early 2010s, studies have identified the critical period and ideal frequency of copper applications to control each disease. Consequently, results have led to an optimized joint spray program replacing the traditional one and an essential reduction in copper use without affecting control quality. These research studies have presented the benefits of copper use reduction, although the potential economic impact has not been calculated. The present study aimed to estimate the value of copper potentially saved by adopting the optimized spray program for citrus canker and citrus black spot control per hectare and in the entire SP citrus belt since 2017, when both diseases began to be managed concomitantly. The optimized program allowed for a ~56 % reduction in metallic copper usage (~10 kg ha–1 per season). This amount of copper saved corresponds to ~120 dollars per hectare per season. Moreover, if the optimized program were to be used throughout the SP citrus belt, the average saving is estimated at ~56 million dollars per season. These results showed that economic analysis reinforces the value of scientific research herein by adjusting disease management for the production chains’ maintenance, development, and sustainability.