CONTROLE BIOLÓGICO DE Helicotylenchus spp. EM SOJA VIA TRATAMENTO DE SEMENTES

Abstract

Soybean is the most important economic crop in Brazil. Many of the losses are caused by nematodes associated with incorrect management. The objective of this work was to test different biological products as seed treatments to determine population effects of nematodes of the genus Helicotylenchus. The experiment was carried out at Fazenda Planalto in the municipality of Planalto Verde, GO. The experimental design used was randomized blocks with 6 treatments, biological products (A. Trichoderma harzianum, B. Bacillus, Pseudomonas, Nitrosomonas and Nitrobacter, C. Pochonia chlamydosporia, D. Ecklonia maxima, E. Bacilus subitilis and B. amyloliquefaciens) and 5 repetitions. Soybean received treatment via seed of products A, B, C, D and E plus the control. The parameters evaluated were germination, number of nematodes before planting and 42 days after planting (DAP) and plot productivity. In the results, there was a 14% reduction in the number of germinated seeds for products A and B compared to the control. In addition, the number of nematodes between treatments did not differ, but there was a significant reduction in treatments that received products D and E of 67.6% and 93%, respectively. Among the treatments, there was no difference in plot yield, but there was a difference compared to the average productivity of the farm. The productivity of the farm was 4,800 kg.ha-1, not differing from the treatment with product B (3,969 kg.ha-1). In summary, the germination, with biopesticide, tested via seed was superior to the preexisting standard chemical treatment in the seed, however the product B had a standard control productivity compared to the other treatments, even presenting a lower germination of the seeds and the treatments with product D and E reduced the population of Helicotylenchus spp. on the ground.