©2018 Pearl Research Journals Effect of nitrogen stress amelioration on status of break flour yield of soft wheat for making bread J. Nakanwagi 1* , J.S. Tenywa 1 , M.I. Mukisa 2 , A. Wasukira 3 , W.W. Wagoire 4 , S. Wobibi 3 , J. Nakamya 1 , D. Beesigamukama 1 and S. N. Aryampa 1 Accepted 10 February, 2018 1 College of Agricultural and Environmental Sciences, Department of Agricultural Production,P. O Box 7062, Makerere University, Kampala, Uganda. 2 College of Agricultural and Environmental Sciences, Department of Food technology and nutrition, P. O Box 7062 Makerere University, Kampala, Uganda. 3 Buginyanya Zonal Agricultural Research and Development Institute, P. O BOX 1356, Mbale, Uganda 4 National Coffee Research Institute P.O Box 185, Kituza, Mukono, Uganda. ABSTRACT Wheat (Triticum aestivum L.) is the largest cereal source of protein (20%) and the second largest source of calories (21%) worldwide. Nitrogen is a major factor that affects bread wheat production in most soils in Uganda. The objective of this study was to determine the effect of nitrogen stress amelioration on break flour yield. A field study was conducted at Buginyanya Zonal Agricultural Research and Development Institute (BugiZARDI) in the highlands of Eastern Uganda, during 2013-2014. Treatments included 0, 30, 60 and 90 Kg N ha -1 with UW400 as test genotype. Site soil N was 0.15%, way below the critical limit of 0.25%. Maximum break flour yield was obtained at 60 kg N ha -1 and the least at 0 kg N ha -1 . There was a direct negative effect of Nitrogen on the level of grain starch; while no significant effect was displayed between Nitrogen application rates and crude protein levels. A weak negative, but significant (P < 0.05) correlation accrued between grain yield and BFY (r=-0.3); while the relationship between starch and crude protein was strong, though equally negative (r=-0.9). The agronomic nitrogen rate required ameliorating nitrogen stress to obtain high break flour and grain yield is 60 kg ha -1 . Keywords: Crude protein, starch, Triticum aestivum, Uganda, UW400 *Corresponding author. Email: nakanwagi11@gmail.com. INTRODUCTION Wheat (Triticum aestivum L.) is the largest cereal source of protein (20%) and the second largest cereal source of calories (21%) worldwide (Paroda et al., 2013), largely consumed as bread. Among the key considerations of the bread industry is break flour, which is one of the parameters that describe milling quality of wheat (starch damage, milling yield, flour protein). Break flour is defined as the total weight of flour obtained from the break rollers on an industrial machine, during the milling process (Miles, 2010). There is scanty information on the relationship between plant nutrition and break flour yield and quality, the understanding of which may be necessary to enhance bread production levels and the overall returns to fertilizer inputs (Edmund et al., 2008). Among the candidate nutrients with the potential to influence the construction of break flour is nitrogen. Nitrogen, through its protein derivatives, is important in sustaining the nature of wheat break flour particles during the milling process, into fine white flour blended for premium bread products (Malik, 2009). On the other hand, excess nitrogen in the soil may result in an imbalance in protein to starch ratio, perhaps exceeding Journal of Agricultural Science and Food Technology Vol. 4 (1), pp. 1-8, February, 2018 ISSN: 2465-7522 Full Length Research Paper http://pearlresearchjournals.org/journals/jasft/index.html