Plant-parasite nematodes in soils cultivated with pecans in Rio Grande do Sul, Brazil

Abstract

ABSTRACT Rio Grande do Sul State produces 70% of pecans in Brazil. There is a high density of phytopathogenic nematodes in orchards. This study characterises the populations of plant-parasitic nematodes and investigates their association with soil properties in pecan-cultivated areas. The genera Mesocriconema, Criconemoides, Discocriconemella, Xiphinema, Tylenchus, Pratylenchus, Helicotylenchus, and Aphelenchoides were all identified. Discocriconemella and Xiphinema were positively associated with soil organic matter, cation exchange capacity, clay content, copper, zinc, calcium, magnesium, and potassium. Conversely, Pratylenchus, Helicotylenchus, Tylenchus, Criconemoides, and Aphelenchoides were positively correlated with aluminium. Mesocriconema, the most commonly found nematode, negatively correlated with most soil chemical attributes. A significant correlation was observed between the genera Criconemoides, Mesocriconema, Aphelenchoides, and Tylenchus. Parasitic nematodes in pecan orchards have not previously been documented in this region of Brazil.