Nematode community associated with commercial cropping of papaya in Paraíba, Brazil

Abstract

This work described the structure of plant nematode community associated with commercial cultivation of papaya in three areas infested with root-knot nematodes in Paraiba, based on community rates and ratios of trophic groups of nematodes. In parallel, it was evaluated stem diameter of plants to establish relationships between plant development and plant parasites in soil. In each area a square of 5,776 m² was split in 400 (20 × 20) squares of 14.44 m² (3.8 × 3.8m), containing three plants. In areas 1 and 3 there was predominance of plant parasitic nematodes, 43.85 and 39.95% respectively, especially Rotylenchulus. In area 2, Meloidogyne was the taxon of highest dominance among the plant parasitic nematodes. In the three areas the maturity index (MI) and the modified maturity index (MMI) were high (> 30 %) and the plant-parasite index (PPI) ranged from 32.88 to 20.95. None of the mathematical models tested described relationships between plant stem diameter and nematode population densities in soil.