Inoculation Methods and Doses and Relationship with the Vegetative and Reproductive Development of Soybeans
David Peres da Rosa *
Soil and Agricultural Machinery Group (NESMA), Instituto Federal do Rio Grande do Sul (IFRS), Campus Sertão, Rodovia RS 135, Km 25, 99170-000, Sertão, RS, Brazil.
Junior Verardi
Soil and Agricultural Machinery Group (NESMA), Instituto Federal do Rio Grande do Sul (IFRS), Campus Sertão, Rodovia RS 135, Km 25, 99170-000, Sertão, RS, Brazil.
Junior Santana Girardi
Soil and Agricultural Machinery Group (NESMA), Instituto Federal do Rio Grande do Sul (IFRS), Campus Sertão, Rodovia RS 135, Km 25, 99170-000, Sertão, RS, Brazil.
Paulo Henrique Conte
Soil and Agricultural Machinery Group (NESMA), Instituto Federal do Rio Grande do Sul (IFRS), Campus Sertão, Rodovia RS 135, Km 25, 99170-000, Sertão, RS, Brazil.
Roger Toscan Spagnolo
Universidade Federal de Pelotas, R. Benjamin Constant - Simões Lopes, 96010-020, Pelotas - RS, Brazil.
*Author to whom correspondence should be addressed.
Abstract
This study aimed to evaluate and compare the method of in-furrow inoculant application with the other existing methods, as well as, in different doses in the development of soybean culture. The experimental design was randomized blocks in a two-factorial scheme (4 x 3), with four inoculation methods, without inoculation (control), by seed, in-furrow and leaf spray, with three doses, 100, 200 and 400%. Leaf and root dry mass, number of nodules, pods per plant, number of seeds per vegetables, height, knots per plant, productivity, root resistance and average chlorophyll content were measured. The combination of factors did not affect plant height, leaf dry matter, root resistance, grains and pods per plant, plant per knot and weight of 100 seeds, affecting only other parameters, in which the largest root dry matter occurred in in-furrow inoculation in the dose of 400%, with 3.82 g plant-1, against 3.43 g plant-1 in the by seed method in the same dose. In the in-furrow application at the 100% dose, the highest number of grains pod-1 occurred, with 3.42 grains pod-1, combined with an increase in pods plants-1, and a 19% increase in productivity relative to the control, and 9.5% at the third increase, in the spray. Co-inoculation methods affect the development of soybeans, and the method that provided the greatest of soybean development was by in-furrow.
Keywords: Biological nitrogen fixation, yield, root development, in-furrow inoculation, sprayer inoculation