Resistance of Coffea canephora as a sustainable tool for Meloidogyne incognita control

Abstract

Many factors can affect coffee production, such as the root-knot nematode, a soil pathogen that can kill plants up to two years old. In infested areas, the cultivation of resistant genotypes is an economical and ecologically appropriate alternative. The present study aims to evaluate the resistance of Coffea canephora clones to Meloidogyne incognita. Evaluations were carried out in a greenhouse at Embrapa Rondônia (Porto Velho -RO) between September 2019 and November 2020. Genotypes were inoculated with M. incognita in four experiments with six replications with a completely randomized design. Root dry weight (RDW), the number of galls (NG) and the reproduction factor (RF) were evaluated. Eighty-six coffee clones were evaluated, with 50 clones showing resistance to Meloidogyne incognita and 36 clones showing susceptibility. Clones classified as resistant had an average reproduction factor of 0.33 with a range of 0.00 to 0.95, while clones classified as susceptible had an average reproduction factor of 3.48 with an amplitude ranging from 1.02 to14.46. The number of galls was also higher in susceptible clones than in resistant clones. Considering the ten most cultivated clones, the genotypes GJ8, GJ25, P50, SK80, AS2, P42 and LB10 were classified as resistant, and the genotypes GJ3, GJ5 and SK41 were classified as susceptible. Taken together, the results identify resistant C. canephora clones as an important and sustainable tool for controlling M. incognita. Key words: Genetic control; Plant resistance; Coffee.