Níveis populacionais de Pratylenchus brachyurus e danos causados em soja

Magalhães, Wanderson BritoCampos, Hércules DinizReis, Camila Gama dosBatista, Priscila FerreiraRosa, Márcio

ABSTRACT: The root lesion nematode, Pratylenchus brachyurus, is frequently found in the root system of soybean plants, causing significant and increasing damage, in addition tosubstantial economic losses. As such, this study aimed to evaluate the damage caused by P. brachyurus in varying soil types and population levels and analyze the correlation between nematode population density and damage severity. The experiment was conducted under greenhouse conditions from November 2019 to March 2020, using a completely randomized experimental design with 10 treatments and 6 repetitions. Shoot (SFM) and root fresh mass (RFM) and root nematode population densities were evaluated. Higher P. brachyurus inoculum densities resulted in larger nematode populations in the soil and soybean roots, regardless of soil type (sandy or clay). Cultivar genetics increased nematode population growth linearly, irrespective of soil type. Thus, SFM and RFM accumulation served as indicators of a higher number of nematodes in the soil and roots of the M7739 cultivar, while the BMX FOCO cultivar showed tolerance to P. brachyurus parasitism, with less reduction in SFM and RFM. An increase in the inoculum density of P. brachyurus did not result in a linear decrease in SFM and RFM accumulation for most cultivars, regardless of susceptibility, in both clay and sandy soils.