Influence of environmental conditions on the performance of the vegetation period in winter common wheat (Triticum aestivum L

The housing conditions are a major factor to change all the traits of bread wheat pertaining to the quality and yield of grain. Whether this is true for the growing season of winter wheat, which is one of the longest in agricultural crops. The aim of this study was to establish the influence of contrasting environmental conditions on the change of basic periods of vegetation, which have a direct connection with the grain yield. Thirty varieties of winter wheat grown in production were studied. They have all the necessary variety of traits and properties of wheat to obtain the maximum possible yield of grain in the country. Cultivars are tested in four consecutive seasons 2007, 2008, 2009 and 2010 in the five locations of Bulgaria, covering all possible variety of soil and climatic conditions for growing wheat. The characters of ear emergence date [EED], grain filling period [GFP] and vegetation period [VP], as major periods of whole wheat vegetation are studied. Data were analyzed using a number of specialized software programs to establish the genotype with the environment interactions. At all traits strong interaction of genotype with the environment is found. The values of the three characters change fairly heavily under the influence of environmental factors. Especially noticeable is the effect of location for vegetation period (VP) and the period of grain filling. In general, the date of the ear emergence change more strongly by the terms of the season and the effect reaches about 50% of the total variation of the trait. Although trait means in the tested varieties are very close, they change the background of the various combinations between the two factors of the environment is so strong that it reaches almost 20% in GFP. The last one is changed greatly in both studied factors. Therefore, it is very convenient for a precise assessment in response to specific genotype in clarifying its impact on the formation of yield and grain quality.