Absolute growth rate in soy varieties (Glycine max L. Merr) developed in the field with two water conditions

Abstract

In order to know the behavior of the Absolute Growth Rate of eight commercial soybean varieties [Glycine max (L.) Merrill.], experiments were carried out at INIFAT areas, on Red Ferralitic soil, using a randomized block design. In the experimental area, two hydric conditions of greater and lesser irrigation by flooding were established. The dry matter of the plants in different ontogenetic stages of the crop was determined 

(30, 51 and 79 days after sowing). As growth index was determined, the Absolute Growth Rate (AGR) and yield components were evaluated. The main results show that at 79 days after sowing, the plants reached the highest AGR in both water conditions, particularly ‘Flora’, ‘Jupiter’, ‘INIFAT-382’ and ‘Cubasoy-120’ varieties. The lowest percentages of TAC inhibition in the low humidity conditions were for the varieties ‘Flora’ with 7.22 %, followed by ‘INIFAT V-9’ with 11.25 % and ‘Jupiter’ with 22.99 %, the others are around 27.5- 50.0 % inhibition. ‘Cubasoy-120’ variety show the highest grains per plant dry weight in relation to the rest, followed by in decreasing ‘INIFAT-382’, ‘Flora’ and ‘Jupiter’, however the variety that had a minimum inhibition of the dry weight of the grains per plant in the conditions of lower humidity was ‘Flora’ with 1.18 %, followed by ‘INIFAT-382’ with 35.28 %, ‘Jupiter’’ with 39.14 % and Cubasoy-120’ variety with higher values of 55.6 %. The best adaptation of the ‘Flora’, ‘Jupiter’ and ‘INIFAT-382’ varieties to low humidity conditions is shown. This work allowed to know the productive potential of each of the varieties and their behavior under low humidity conditions, which allows a better use of the diversity of this species.