Impacto dos atributos químicos do solo e das culturas na distribuição de nematoides entomopatogênicos

Abstract

The presence of entomopathogenic nematodes (EPNs) in the soil is directly related to edaphic conditions and agricultural management, influencing their distribution and persistence. This exploratory study aimed to map the natural distribution of EPNs in areas with different crops and investigate possible correlations between their presence, the types of plants cultivated in the sampled regions, and the soil chemical properties. To this end, the occurrence of EPNs was assessed at 82 sampling points collected between January and May 2024 across five crops (atemoya, pitahaya (dragon fruit), avocado, passion fruit, and coffee) in the Monte Carmelo region, Minas Gerais, in a Dystrophic Red Latossol. Samples discarded the superficial layer (035 cm) and targeted a depth of 5315 cm, with coordinates recorded via GPS. Isolation involved bioassays using six Tenebrio molitor L. larvae in soil samples, disinfection with 0.1% sodium hypochlorite, the use of White traps to obtain infective juveniles confirmed by Koch’s postulates, and subsequent incubation in a B.O.D. chamber at 16 ± 2 °C. For spatial evaluation, ArcGIS Desktop 10.0 with the Spatial Analyst extension was used to generate situation maps (Kernel Density), continuous surfaces of soil chemical attributes (Top to Raster and isolines), and correlation maps through layer overlay. Results indicated variation in EPN occurrence among crops and different edaphic attributes. Geospatial analysis allowed inference of EPN distribution patterns based on soil chemical characteristics; however, no specific causality was attributed given the preliminary nature of the study. The findings contribute to understanding the spatial dynamics of EPNs in relation to soil chemistry and crop type, providing a basis for future, more detailed investigations.