Influência da calagem no manejo de fitonematoides

Abstract

Brazil is a country that has the agricultural sector as its main pillar, more specifically the production of grains for export. However, its competitiveness and sustainability have been threatened by high population levels of phytonmatoids, making studies necessary to control these parasites necessary. The objective of this work was to evaluate the effect of limestone doses on the population of phytonmatoids in soil and soybean root in a naturally infested area. In the 2018/2019 harvest, the experiment was implemented at Fazenda Monte Alegre, located in the municipality of Nova Xavantina - MT. The area was divided into randomized blocks, with six treatments and four blocks, totaling twentyfour plots, with dimensions of 7m x 7m, where the treatments were carried out, being: treatment (1) without application of limestone, treatment (2) two tons ha-1 , treatment (3) four tons ha-1 , treatment (4) eight tons ha-1 , treatment (5) twelve tons ha-1 , treatment (6) sixteen tons ha-1 of limestone. To incorporate the limestone, a 34 inch plow harrow was used. Samples to assess population density and frequency of eggs, juveniles and adults of the various genera of phytomatomatoids were performed during the grain filling period, phenological stage R5.4. The samples analyzed in laboratories identified the presence of Pratylenchus penetrans, Heterodera glycines and Helicotylenchus dihystera, in the soil and root. Through increasing doses of limestone, it was noted a reduction in the population density of P. penetrans in the soil and H. glycines in the roots. Doses of up to 10.9 t ha-1 reduced the number of H. glycines eggs in the roots, tending to increase from this dose. The soybean yield was higher in the treatment of 4.99 t ha-1 of limestone.