Were this the cause of
the relatively low percentage of nitrogen in the American wheats, the
grain from the Eastern States, which are poorest in this respect,
would be heavier than those from the middle West, which are richer in
albuminoids; but this is not the case. Formation of starch is
attributed by Messrs. Lawes & Gilbert to the higher ripening
temperature in America, but Clifford Richardson has found that there
is scarcely any difference in composition or weight between wheats
from Canada and Alabama, and if anything those from Canada contain
more starch than those from the South, and the spring wheat from
Manitoba with its colder climate more than those from Dakota and
Minnesota, with its milder temperature. In Oregon is found a striking
example of the formation of starch and increase in the size of the
grain, at the relative expense of the nitrogen, due to climate, but
not to high ripening temperature. The average weight per hundred
grains of wheat from this State has been found to be 5.044 grains, and
the relative percentage of nitrogen 1.37, equivalent to 8.60 per cent.
of albuminoids. These are the extremes for America, and are due, as
has been said, to the enhanced formation of starch.
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