Aug, 15 , 1914 
Head Smut of Sorghum and Maize 
349 
produced it also on maize and described the form foliicola. While he 
states (1900, p. 18) that infection from seed-borne spores takes place and 
that, therefore, seed treatment with fungicides is of value, he had, like 
Passerini, produced the disease, in the field, only on maize and in very 
small quantities. Clinton (1900, p. 347) also failed to produce any 
infection by inoculations of the seed and young plants. Hori (1907, 
p. 163, 166) reports entirely negative results from inoculations, but 
claims that a hot-water treatment has been shown to prevent the disease. 
McAlpine (1910, p. 296) produced infection in a single maize plant by 
seed inoculation and on this basis recommended seed treatment with 
copper-sulphate solution as a preventive. Johnston (1910 or 1910a, 
p. 44) has also recommended seed treatments, and this Australian idea 
has been copied by Mundy (1910, p. 4) in South Africa. 
Fig. 3.—Curves summarizing for different years the percentages of infection in plantings of sorgo after 
all hot-water treatments and in control plantings. 
The early inoculation experiments of the Office of Cereal Investigations, 
involving about a thousand plants of different varieties (including kafir 
and sorgo) in the field at Amarillo, gave results similar to those cited 
above—i. e., little or no infection resulted from the presence of an abun¬ 
dance of spores on the seed. 
SEED AND SPORE TREATMENTS 
In full accord with the negative results of these inoculations our 
experiments have conclusively shown that the most severe treatments 
of the seed, though carefully performed, do not prevent the attack of 
the parasite. These treatments have involved some 35,000 or more 
plants, of which about two-thirds were in tests of thermal methods, the 
