Adaptability and stability of soybean cultivars in four sowing seasons

Abstract

In recent decades, the expansion of soybean production in Brazil has been observed. This advance was motivated by the search of environments with better cultivation conditions, as well as the development of genotypes with wide adaptation. The diversity of "environments" hinders the process of selection and recommendation of cultivars, since the productive potential of a cultivar is given as a function of the sum of the genotype effect, the environment and the interaction between the latter two (G x E). In the case of this G x E interaction, regional studies are necessary in order to detail the differential behavior of the cultivars. Thus, the objective of this work was to evaluate the genotype interaction by environments, adaptability and phenotypic stability for grain yield, of fifteen soybean cultivars, in four sowing seasons, in order to identify cultivars that combine high productive potential, predictability of behavior and adaptation to the edaphoclimatic conditions of Uberlândia-MG. The trials were conducted at the Experimental Farm Capim Branco, in Uberlândia-MG. Fifteen soybean cultivars were evaluated in four sowing seasons (October 23, 2016, November 19, 2016, December 10, 2016 and January 14, 2017), in relation to grain yield. The experimental design was of randomized complete blocks, with three replications, in each season. Data were submitted to individual and joint analyzes. The G x E interaction was decomposed by the method proposed by Cruz and Castoldi (1991). The differential behavior of the genotypes was detailed by the adaptability and phenotypic stability by the methods of Eberhart and Russell (1966), Lin and Binns (1988) modified by Carneiro (1998), AMMI and Centroid. By the analysis of joint variance, it was observed the existence of the cultivar interaction by sowing times (C x E), for the grain yield trait, at the 5 % probability level by the F test. The C x E was predominantly complex in nature. The cultivar CD 2737 RR presented satisfactory results for the four sowing seasons in Uberlândia-MG, with high grain yield and predictability of behavior, by the evaluated methods. The cultivar NS 6909 IPRO was classified into favorable environments by the methods of Eberhart and Russell (1966) and Lin and Binns (1988) modified by Carneiro (1998). Considering Lin and Binns (1988) modified by Carneiro (1998) and Centroid the cultivar that is also classified for this cultivation condition is UFUS 8301. By AMMI, UFUS 7415, CD 2737 RR and UFUS Milionária are considered stable and adaptable.

Ascophyllum nodosum Extract (SealicitTM) Boosts Soybean Yield Through Reduction of Pod Shattering-Related Seed Loss and Enhanced Seed Production

“…It should be noted that little information is available on the susceptibility of these short-cycle Canadian varieties to pod shatter, so additional trials were performed with soybean varieties with known shatter susceptibility to investigate the potential of Sealicit TM in this crop. The harvested seed yields at full maturity for the Brazilian varieties SS and SR were in the range expected in previous field trials developed in four consecutive sowing seasons in Uberlândia-MG ( Bicalho et al, 2019 ). All treated soybean varieties with Sealicit TM produced increased yield with respect to their untreated counterparts.…”

“…Pod shattering resistance tests performed on soybean control pods showed variability in treated varieties, ranging from 4 h for SS to 48 h for SR, proving the robustness and sensitivity of the method. The difference in calibration time was to be expected as both varieties are genetically diverse ( Bicalho et al, 2019 ). On the other hand, the SR variety, classified as resistant to shatter, showed no statistically significant improvement after Sealicit TM treatments, whereas the SS variety, classified as susceptible to pod shattering, showed a very significant fruit firmness increase across all the doses applied.…”

“…The impact of Sealicit TM on soybean yield was assessed using a randomized block field trial design at two distinct geographical locations (Canada and Brazil) with four different varieties. Employing multiple experimental approaches, the impact of Sealicit TM on plant and pod phenotypic traits and pod firmness were assessed for two Brazilian soybean varieties UFUS 6901 [shattering-susceptible (SS)] and UFUS 7415 [shattering-resistant (SR)] ( Bicalho et al, 2019 ). In order to decipher the MOA at the molecular level, the expression of soybean pod shattering genes, GmPDH1.1 and GmSHAT1–5 were also evaluated.…”

Soybean tolerance to defoliation at the vegetative and reproductive stages as a function of water restriction

“…Additionally, cultivars with indeterminate growth habits have an extended period of overlap between the vegetative and reproductive stages (Zanon et al, 2015b), which may have mitigated the effects of water deficit at the R3 stage. Moreover, the productive stability of the cultivar NA 5909 RG has been reported under different cultivation conditions (Matei et al, 2017;Câmara, Moraes, & Simon, 2018;Bicalho et al, 2019). It also contributed to similar grain production losses with a severe water deficit in the vegetative and reproductive periods.…”