PRODUTO BIOLÓGICO APLICADOS VIA TRATAMENTOS DE SEMENTES NO MANEJO DE Pratylenchus brachyurus NA CULTURA DA SOJA

Abstract

Root-lesion nematode has caused high economic damage in soybean crop, presenting wide dissemination in Brazilian soils. Aiming at the management of this nematode, the present work was developed with the objective of evaluating the efficiency of different biological control agents in the management of Pratylenchus brachyurus in soybean crop. The assay was conducted in a field naturally infested with P. brachyurus, in a randomized block design, with four replications, using the soybean cultivar Desafio RR. The treatments of seeds evaluated were: T1 - Control (untreated); T2 – Purpureocillium lilacinus +Trichoderma harzianum 100kg seeds-1; T3 - Trichoderma harzianum 100kg seeds-1; T4 - Pochonia chlamydosporia.100kg seeds-1; T5 - Bacillus methilotrophicus100kg seeds-1; T6 - Bacillus subtilis + Bacillus licheniformis 100kg seeds-1, at doses recommended by manufacturers. The fresh root mass, the number of P. brachyurus/10g of root and in 100cm3 of soil at 45 and 70 days after sowing (DAS) and productivity at the end of the crop cycle were evaluated. No differences were observed between treatments and times for the number of nematodes per 10g of root and 100 cm3 of soil. The same behavior was observed for productivity, in which only T4 had an increase of 2.88% in relation to the control. Thus, the biological treatments evaluated in this study did not reduce the population of P. brachyurus in soybean and did not promote productivity increases.