Characteristics of soybean sortoobrazets for preliminary competitive strain testing on adaptiveness
The article presents the researches in 2008-2012 on the reaction of soybean varieties genotype of Far East State Agrarian University selection 686, 452, 477, 472 to the external environmental conditions and its stability in the southern agricultural zone of the Amur region. In order to anticipate the behavior of varieties under production conditions the parameters of adaptive properties of soybean varieties for yield by the method of Eberhart E.A. and Russell W.A. were evaluated. Sowing nurseries for prior competitive test was performed according to the methods of state crops tasting (1985) by random repetitions in four replications. Plot area - 50 m <sup>2</sup>. Experienced varieties were compared with standard - Lydia ( early maturing ) and Harmony ( middle maturing). Environmental index in 2008, 2010 and 2012 was 0,46; 0,40 and 0,13 accordingly that characterized the years as the convenient for genotype growth and development, in 2009 and 2011 - - 0,74 and - 0,23 that pointed on the unfavorable conditions for vegetation. Phenotypic expression of varieties’ yields varied in the diapason of 2,81... 3,75 t <sup>-ha</sup> in 2008, 1,9... 2,15 t <sup>-ha</sup> - 2009, 2,74... 3,38 t <sup>-ha</sup> - 2010, 2,32... 2,65 t <sup>-ha</sup> - 2011 and 2,5... 2,85 t <sup>-ha</sup> - 2012. The yild of variety 686 fluctuated in the range of 1,90... 3,33 t <sup>-ha</sup>; 452 - 1,97...3,75 t <sup>-ha</sup>; 477 - 2,0... 3,33 t <sup>-ha</sup>; 472 - 2,15... 3,34 t <sup>-ha</sup>, indicating that differences not only in the level of productivity, but also in the reaction to the conditions of the year. Soybean varieties 686, 477, 472 and Harmony were characterized by high level of environmental plasticity and stability - the level of productivity depends on agricultural treatment. Variety 452 had average values of these characteristics - high yield is formed at a high level of agrotechnique. Variety Lydia had an average plasticity index and low - stability that indicates to the difficulties in predicting its yield.