. Bulletin. Natural history; Natural history. Diseases of Grain Crops, 1922-1926 77 The destructiveness of the diseases of oats, barley, and rye may be regarded in the same way as the diseases of wheat. A statement of their destructiveness may be made, consequently, by omitting summarizing tab- ulations like that given above for wheat diseases and using, in their stead, illustrations similar to F"igure SI). In Figure HO, the total effect of disease attack on oats, as indi- cated by the indexes of destructiveness given in previous pages, is illustrated for each year in comjiarison with an
. Bulletin. Natural history; Natural history. Diseases of Grain Crops, 1922-1926 77 The destructiveness of the diseases of oats, barley, and rye may be regarded in the same way as the diseases of wheat. A statement of their destructiveness may be made, consequently, by omitting summarizing tab- ulations like that given above for wheat diseases and using, in their stead, illustrations similar to F"igure SI). In Figure HO, the total effect of disease attack on oats, as indi- cated by the indexes of destructiveness given in previous pages, is illustrated for each year in comjiarison with an undiseased stalk of aver- age jiroportions. The stature of the stalk is shown reduced 29 per cent by stem rust attack in 1922, not at all in I'.ri'A. 1 per cent in 1924, per cent in 1925, and per cent in 1926; the normal leaf complement is illustrated as being reduced per cent by the com- bined attacks of crown rust and halo blight in 1922, per cent in 192;i, per cent in 1924, per cent in 1925, and per cent in 1926; and the sjjikelets are depicted as reduced per cent by scab and loose smut in 1922, ;;t8 per cent in 1923, per cent in 1924, per cent in 1925. and per cent in 1926. The destructiveness indicated by the indexes given previously for barley diseases is shown in Figure 91. In coni])arison with a barley stalk. Flo. 91. of barley , 1922-1926 The effect of disease attack upon the stems, leaves, and panicles of barley, as indicated by the indexes of destructiveness given in the text, is shown in comparison with an average healthy stalk. See the text on pages 75-77 for further Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natural History Survey Division. Urbana, State of Illinois, Dept. of Regi
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