Abstract
Plant-parasitic nematodes Meloidogyne incognita and Pratylenchus zeae are commonly associated to sugarcane in Brazil causing serious problems. Thus, the objectives of this study were to determine the reproductive rate of M. incognita and M. enterolobii in sugarcane when inoculated in isolation and together with P. zeae and the effects of this interaction on the early development of two varieties of sugarcane. Two experiments were performed. In the first experiment, three different population densities of M. incognita and M. enterolobii were inoculated in both sugarcane varieties. In the second experiment, inoculation of P. zeae followed by inoculation with M. incognita or M. enterolobii was carried out. Meloidogyne enterolobii did not show good development in both sugarcane varieties after 120 days of infestation; contrary to M. incognita, which reached high population levels. Fresh and dry shoot biomasses were lower under joint infestation of P. zeae and Meloidogyne. In mixed infections, P. zeae suppressed the development of M. incognita and increased the multiplication of M. enterolobii in the variety RB867515 whereas the contrary was observed in the variety RB92579, demonstrating once more the resistance reaction of this variety to M. enterolobii.