122 
Colorado Experiment Station 
That the effect of rust is practically to inhibit this transfer. 
That, for the production of the best wheat, there exists an optimum 
ratio between the nitric-nitrogen and available potassium in the soil. 
That, if the potassium predominates, yellow-berry is produced. 
That, if nitric-nitrogen predominates, soft, weak plants, small, 
flinty, and often shrunken berries result. 
That, so far as the crushing strength is a proper criterion whereby 
to judge, our wheats range from semi-hard to hard. 
That, so far as composition is concerned, our wheats, produced 
under normal conditions, i.e-, when the plants are free from rust, stand 
well above the average. 
That our soil varies in character to such an extent that there is no 
general average composition of the wheat produced that can be con¬ 
sidered characteristic. 
That our climatic conditions are so favorable that differences in 
composition are, for the most part, attributable to other immediate 
causes. 
That rust causes a very marked depression in the protein con¬ 
tent of the wheat, even if the crop is well advanced at the time that 
the rust attacks the plants. 
That rust increases the percentage of crude fiber in the wheat 
by preventing the filling out of the berries. 
That the effects of the fertilizer upon the composition of the 
wheat and the production of flinty berries, or the increase in the yellow- 
berry, are not eliminated or concealed by the unfavorable conditions 
that we had in 1915. 
That, on the other hand, the effects of the nitric-nitrogen in in¬ 
creasing the protein content of the wheat was rather emphasized there¬ 
by. 
That, in 1915, we have shown three classes of effects in the plants, 
those due to fertilizers or soil, those due to weather and those due to 
rust. 
That of these, those due to rust were by far the most marked and 
were prejudicial in their character. 
That the effect of rust on the grain is to prevent the transfer of 
the filling material to the berries- 
That the shrunken berries due to this cause are not high in protein. 
