Aug. is, 1914 
Head Smut of Sorghum and Maize 
361 
“III.” Seed from a head grown at Amarillo in 1911, which had been kept 
covered with a transparent paper bag from before flowering until thrashed out by 
hand. The parentheses simply indicate a different head as the source of seed. 
“IV.” Seed from heads grown in the greenhouse at Washington, D. C., during 
the winter of 1911-12 and kept covered, as above, from before flowering until 
thrashed out by hand. 
“V.” Seed without glumes (separated in water, as in I); from the crop of 1911 
at Akron, Colo. Treated with 0.16 per cent formaldehyde solution for 10 minutes 
after a thorough washing. 
“Spore Tot.”—The mixed lot of spores used is so indicated; the other five lots, all 
collected from Red Amber sorgo at Amarillo, are indicated as follows: 
“A.” Collected in the fall of 1910. 
“B.” Collected in September, 1911. The parentheses indicate conidia from 
cultures first isolated from single spores of this lot (see p. 341) in February, 1912. 
“C.” Collected in the fall of 1912. 
“Method.”—The methods used in making inoculations are classified— 
First, as to the condition of the host plant when inoculated (or planted, in 
the controls): 
“a”=dry seed; 
“ b ’ ^germinating seed; 
“c older plants. 
Second, as to the character of the inoculating material: 
“m”=dry spores; 
“n ’’—suspension of spores in which a few were germinating; 
“p”=conidia. 
Third, as to the general procedure in inoculating: 
“x”=heavy application of a mass of the inoculating material, usually so as to 
completely cover the seed or seedling when planting it, or, on older plants, to 
cover the inoculated part; 
“y”—lighter application—dusting of dry spores before planting or spray of 
material in water; 
“z”=inoculation of the plat by raking smutted heads into the soil after plow¬ 
ing in the spring. “ zz ” in plat C, No. 7—inoculation two years in succession, the 
same plat being used as for plat A, No. n, the year before. 
Fourth, the controls, which were not artificially inoculated, are indicated in 
this column. 
Fifth, special methods in inoculation are indicated by parentheses, as follows: 
“bm(x)” in plat A, No. 7=the soil in the opened row was heavily inoculated 
at planting; 
“bn(x)” in plat B, Nos. 1 and 2, plat D, No. 1, and plat E, No. 1, and 
“bp(x)” in plat C, Nos. 1 and 2, plat D, No. 2, and plat E, No. 2=both seed¬ 
ling and soil were inoculated; 
“cm(x) M in plat C, No. 8, plat D, No. 8, and plat E, No. 5=the spores were 
placed about the root crown just beneath the surface of the soil; 
“cp(x)” in plat E, No. 6 = the conidia were taken from carrot-agar culture and 
smeared on the base of the plant with a flat inoculating needle; 
“bm(y) t ” “bn(y),” and “b(control)” in plat E, Nos. 8, 9, and io=the ground 
was thoroughly wet down both before and after planting, the seed only being 
inoculated; 
“bn(y)” in plat A, Nos. 1 and 2=the seed only was inoculated; 
“bn(y)” in plat A, Nos. 3 and 4=the soil only in the opened row was inocu¬ 
lated; 
“cp(y)” in plat C, No. 9, and plat D, No. 9=conidia were sprayed on the root 
crown, which was then re-covered with moist earth. 
