Performance of soybean cultivars under drought stress and sowing seasons in Brazilian Savannah

Abstract

Objective: Evaluate the performance of two soybean cultivars submitted to water deficit in two sowing seasons (July 10, 2019, and October 27, 2020), in Tocantinense Savannah, Brazil.
 Methodology: The experiments were carried out in a greenhouse, in pots. The experimental design used in each experiment was completely randomized in a 4 x 2 factorial scheme with four replications, represented by four irrigation management systems (water deficit in the flowering, grain filling and maturation stages, and without water deficit) and two cultivars (TMG132RR™ and TMG1288RR™). The means were grouped by the Scott-Knott test at 5% significance. The characteristics evaluated were: number of seeds per plant, mass of one hundred seeds in grams, number of pods per plant, plant height and grain yield per hectare (GY) in kilograms.
 Results: In the two seasons, the water deficit during grain filling affected the number of pods and seeds per plant, the 100 seeds mass, and the grain yield of both cultivars.
 Implications: The water availability and sowing seasons are environmental factors with the greatest impact on cropping. Therefore, understanding how cultivars behave in adverse environmental situations is of great importance to management programs.
 Conclusions: The cultivar TMG132RR™ was less sensitive to water deficit, whereas the cultivar TMG1288RR™ was more productive under adequate conditions of temperature and water availability.