Phytopathogenic nematofauna of commercial seeds of tropical forages

Abstract

The objective of this work was to identify and quantify the phytopathogenic nematofauna of forage seeds destined for internal and external markets. Seeds of Brachiaria brizantha (cvs. Marandu and Xaraés), B. decumbens cv. Basilisk, Panicum maximum (cvs. Massai, Mombaça and Tanzania), and Stylosanthes capitata and S. macrocephala, components of cv. Estilosantes Campo Grande, were examined. The extractions were made by centrifugal flotation in solution of sucrose with kaolin. Aphelenchoides and Ditylenchus genera were detected in forage grasses. The highest number of Aphelenchoides spp. specimens was observed in seeds of cv. Marandu, followed by seeds of cvs. Xaraés, Basilisk, and Tanzania. Regarding Ditylenchus spp. population density, higher values were detected in seeds of cvs. Marandu, Xaraés, and Basilisk. The results suggest that two or more species of Aphelenchoides and Ditylenchus are associated to forage grass seeds destined for Brazilian market. Phytopathogenic nematodes are not detected in Estilosantes Campo Grande seeds, neither in seeds of cvs. Marandu, Mombaça and Tanzania destined for exportation.