Reaction of common bean genotypes to the reproduction of Meloidogyne javanica and Meloidogyne incognita

Abstract

The production of common bean (Phaseolus vulgaris L.) may be compromised by a variety of pests and diseases, with root-knot nematodes standing out among the soil-borne pathogens that cause significant losses. It was assessed the reaction of common bean genotypes to the reproduction of these nematodes, with emphasis on the two species most frequently found parasitizing the crop: Meloidogyne javanica and Meloidogne incognita. The experiments were conducted in a greenhouse, using a completely randomized design, with 26 treatments (genotypes), ten replications and plot consisting of a pot containing one plant. Each plot was inoculated with 1,000 eggs and second-stage juveniles and assessed at 62 days after the inoculation, when the final populations were estimated. The genotypic resistance was determined based on two criteria: reproduction factor and index. All the genotypes were susceptible to M. incognita according to both assessment criteria. The IAC Alvorada, IAC Imperador, BRS Esplendor and BRS Esteio cultivars, although may be classified as resistant to M. javanica by the reproduction factor, are classified only as moderately resistant if the assessment criterion is the reproduction index.