PLANTAS DE COBERTURA NA PRODUTIVIDADE DE SOJA E POPULAÇÃO DE NEMATOIDES

Abstract

ULIANA, Irumuara Interaminense. Coverage plants in nematoid soy and population productivity. 2019. 36p. Dissertation (Postgraduate Program in Bioenergy and Grains). Goiano Federal Institute of Education, Science and Technology - Rio Verde Campus, Rio Verde, GO, 2019. Advisor: Dr. Adriano Perin.

The objective of this study was to verify the different cover crops responses on Monsoy 7110 IPRO soybean yield and its effects on the nematode population. The experiment was carried out at Fazenda Coqueiros do Rio Doce, located in Rio Verde, Goiás State, in the 2017/2018 agricultural year. The following five types of cover were implemented at this location: 1) Crotalaria spectabilis; 2) Corn with C. spectabilis; 3) corn with Urochloa ruziziensis; 4) corn; 5) U. ruziziensis. The soybean crop was established on four cover types, at follows: 1) C. spectabilis; 2) corn with C. spectabilis; 3) corn with U. ruziziensis; 4) Corn. At the beginning of October 2017, the areas were desiccated with the herbicide glyphosate at a dose of 1.1152 kg e.a.ha-1. The experimental design was randomized blocks with four replications. At pre-harvest, plant height, first pod insertion height, pods per plant number and grain yield (estimated yield in kg ha-1) were measured. To verify nematode dynamics, soil samples were taken from the five cultivated areas, following the following schedule: before planting (time zero) and 30, 60, 90 days after soybean emergence (DAE). The composite samples (300 cm3 of soil) were collected (0-20 cm deep) and separated by the float-sedimentation-sieving method, followed by centrifugation. Identification was based on taxonomic keys. The results were subjected to analysis of variance (F test), with means being compared by Tukey test at 5% probability. The soybean cultivated on corn straw with or without C. spectabilis showed higher yield. At 60 DAE of soybean, the Pratylenchus spp. population increased significantly, regardless of the coverage plant. Soils with U. ruziziensis covers do not change for lesion nematode population. However, when previously cultivated with corn, they tend to increase the Pratylenchus spp. population Keywords: Glycine max, productivity, nematodes, Crotalaria spectabilis, Urochloa ruziziensis.