Compatibilidade de nanopartículas de micronutrientes com fungicidas no manejo da ferrugem do cafeeiro

Abstract

Brazil is the world's largest producer and exporter of coffee, with Minas Gerais state responsible for a large part of the national production of Coffea arabica. Despite the economic relevance and positive figures of Brazilian coffee farming, several factors can limit productivity, such as nutritional imbalances, water deficits, frosts, pests, and especially diseases. Among these, coffee rust (Hemileia vastatrix) is the main one, capable of causing significant losses in productivity and quality, in addition to increasing production costs due to the need for frequent spraying with copper-based fungicides, triazoles, and strobilurins. Sometimes, these fungicides are mixed directly in the tank shortly before application; however, this mixture can result in alterations in the physicochemical properties, influencing the efficiency of the products used, as well as interfering with the dissociation levels of the active ingredients. Therefore, the effectiveness of the products can be altered synergistically, additively, or antagonistically, potentially reducing the efficiency of rust control. Copper fungicides are recommended in high doses, from 1 to 2 kg of metallic copper per hectare per application. Therefore, the application of smaller quantities is necessary, in line with new legislation and the global demand for sustainable crops. To maintain the effectiveness of copper, a fungicide widely used in managing resistance to phytopathogens and in nutrition, the use of copper nanoparticles can contribute to improving new strategies for managing coffee diseases, as they have a high potential in suppressing fungal and bacterial pathogens. Therefore, it is necessary to intensify investigations into the effectiveness of copper nanoparticles and other micronutrients in managing coffee diseases and their compatibility with other phytosanitary products used in coffee cultivation, in mixtures made directly in the tank.