Variation in wheat protein content : the effect of environment

Over the past 20 years, the average protein content of WesternAustralian wheat has ranged from 9.3 to 12.0 per cent, with a mean level of 10.4 per cent. At most grain receival points, in any one season, individual loads can often vary in protein content by as much as 5 per cent protein or more. Rainfall and soil fertility account for much of this variation