INFLUENCE OF LATE NITROGEN APPLICATION ON NITROGEN TRANSLOCATION AND PROTEIN-FRACTIONS OF WHEAT GENOTYPES DIFFERING IN PROTEIN-CONTENT (REPRINTED FROM PLANT NUTRITION FOR SUSTAINABLE FOOD-PRODUCTION AND ENVIRONMENT, 1997)

To investigate the influence of late nitrogen application on nitrogen translocation and protein fractions, three wheat genotypes differing i n protein content were studied in pot experiments at low and high fert ility regimes with late foliar nitrogen application. At high fertility , late nitrogen application increased N translocation and improved N t ranslocation efficiency greatly, however, cultivar differences were fo und at low fertility. Late nitrogen application increased both leaf an d chaff N translocation, and increased culm N translocation only at hi gh fertility. Relative contributions of vegetative components to N tra nslocation efficiency were altered by late nitrogen application. Album ins and gliadins contents at maturity were also observed. Xin Kehan No . 9, the high yielding, low grain protein content cultivar showed no c hange in glutenins content resulting fr om late nitrogen application. Glutenin content of Dongnong 7742, the high yielding high grain protei n content, decreased slightly, and Robin, high grain protein but low y ielding cultivar decreased only at high fertility. Residual protein co ntents were significantly increased by late nitrogen application for a ll cultivars. It was concluded that nitrogen applied at later stage co uld be used efficiently only at high fertility, and most of the N tran slocated were used for the synthesis of residual proteins.