Efficacy of chemical and biological nematicides in the management of Meloidogyne paranaensis in Coffea arabica

Abstract

Coffee crop is of high importance to the Brazilian agriculture, but plant-parasitic nematodes, especially the root-knot nematode Meloidogyne paranaensis, can reduce the productivities of coffee plants. The management of nematodes in coffee is done mainly with the use of resistant plants and chemical and biological nematicides, mainly in large-scale farms. Nevertheless, there is scarce information about the efficacy of available nematicides and new molecules in the control of root-knot nematodes in coffee. Thus, the objective of the present work was to evaluate the efficacy, under greenhouse conditions, of four chemical (cadusafos, carbofuran, fluopyram, and fluensulfone) and two biological (Purpureocillium lilacinum and Trichoderma harzianum) nematicides and one organo-mineral compost in the control of M. paranaensis, the main nematode species for Paraná coffee production. For this, coffee plants of the cultivar Mundo Novo with four to five pairs of leaves were transplanted to 3.6 L-capacity plastic pots and inoculated with 1,000 eggs of M. paranaensis; noninoculated plants were used as control. Nematicide treatments at the recommended dosages by manufacturers were done soon after the transplant and inoculation or 60 days after. Evaluations were done 120 days after the inoculation on the basis of nematode reproduction factor (RF) and number of nematodes per gram of root (Nema/g). Additionally, the development of plants was measured by the variables plant height, fresh top weight, and fresh root weight. The results showed that the best nematicides to reduce nematode population were fluensulfone and fluopyram, with 99% and 100% reduction of the nematode RF, respectively. Carbofuran and cadusafos, although controlled the nematode, caused phytotoxicity to coffee plants. Biological nematicides were not effective in the reduction of the nematode population, but the application of P. lilacinum provided better development of plants. These results have high relevance, as they demonstrated the effect of chemical molecules and biological agents, both in M. paranaensis-infected plants and in noninfected plants; with this information, growers can choose products with a higher nematicidal effect and that allow better plant development for use in infested fields.