Baking quality in wheat : effect of delayed harvest, cultivars, growing conditions and nitrogen fertilization

Abstract: FN, protein percent and gluten quality are amongst the most important quality parameters that determine the baking quality of wheat. Rainfall after physiological maturity causes PHS which reduces grain quality and value. To determine the effect of delayed harvest on PHS five spring wheat cultivars were used such that they were harvested one week after yellow ripeness, and then in 3 days interval for a period of six weeks. FN for each variety and harvest time was determined, as well as protein content and SDS sedimentation volume. Data from another set of wheat samples was used to study the effect of environment and nitrogen fertilizer on these quality parameters. This comprised data from the on-going research project, Future Wheat obtained from field trials of 12 varieties which were grown in Vollebekk and Apelsvoll in 2009, 2010 and 2011. FN, protein content and SDS sedimentation value was determined for each varieties and locations. Results showed that FN, protein content and SDS sedimentation values were affected by delayed harvest. The FN showed stable and high values for a long time period (approximately one month), and then it decreased. Except Demonstrant all other 4 varieties maintained FN > 200 (threshold level set for bread wheat in Norway) until last harvest. These results are discussed against the actual weather data and the development of dormancy. Significant effects of environment, variety and N fertilization were found for FN, protein content, SDS sedimentation value and specific SDS value. Additional N fertilization at heading increased protein content and SDS sedimentation values in all varieties