* . . “> Tate. tie 
18 BULLETIN 1210, U. S. DEPARTMENT OF AGRICULTURE. 
Miller and Molz (275, 276) report on additional methods of seed 
treatment. Germination tests were made in moist chambers and in 
the open field involving the sowing of 8,000 grains in each trial. 
Entire bunt prevention was obtained in but one case, viz, when para- 
formaldehyde was used, but this fungicide showed the highest degree | 
of seed injury. P 
Reynolds (323) performed extensive experiments with many | 
fungicides to determine their protective properties against reinfesta-_ 
tion. His conclusions were that any treatment involving the use 
of copper sulphate, except immersion in Bordeaux compounds, was 
highly protective, and that aftertreatment with lime reduced the 
peer: Dry copper carbonate mixed with the seed gave the 
est results. 
Saunders, Bedford, and Mackay (332) in 1893 recommended copper 
sulphate in preference to other media for treatment because of its 
protective action against infection from bunt-infested soil. But so 
_ far as the authors have been able to ascertain no experiments of this 
kind had been undertaken in highly infested soil. It was thought 
that a sufficient amount of soluble toxin might be made to adhere to 
the seed to establish an immunizing zone around the grain which 
would prevent or reduce the infection from infested soil. Obviously 
it could not be expected that protection by means of seed-borne 
fungicides could be made to extend to the surface of the soil, but it 
was hoped that it would be effectual in the region where the seedling 
s most subject to infection, 1. e., immediately above the seed. 
ee a i ee ell et ee oe ee 
VARIETAL RESISTANCE TO BUNT. 
In 1764 N. E. Tscharner (371) stated that for several years he had 
sown a mixture of red and white spelt and always found much less 
bunt in the former. It was not until 130 years later, however, that 
a scientific search was begun for resistant varieties. 
In 1900 William Farrer (110), the noted wheat breeder of New South 
Wales, reported on a number of varieties which he had studied. 
His investigations must have been made under severe conditions, 
for with two exceptions the average percentage of bunt was 83. 
Kiihn (225) noted that certain varieties were less susceptible to 
bunt than others and suggested that this fact might be related to_ 
moisture content of the plant, i. e., that low moisture content might 
enable the plant to resist entrance of the mycelium or to check its 
spread within the host. ; 
Tubeuf (372, 374) gives in great detail the results of extensive 
varietal resistance experiments. He noted the number and_per- 
centage of plants partly bunted, as well as the number of sound and 
bunted heads appearing in each of such plants. Tubeuf is of the 
opinion that resistance is correlated with the varietal characters of © 
prompt germination and rapid growth up to the point where infection 
is inhibited, i. e., the appearance of the first leaf. He found Ohio,* — 
Ontario, and Bestehorn’s Ueberfluss highly resistant. He suggests 
the possibility of increasing the resistance of a variety by selection 
through a long period of years. He found no uniform improvement 
as a result of selection for only one year. 
Appel and Gassner (15) mention Ohio and Strubes Grannenweizen_ 
as being constantly resistant. Kirchner (204) published the results 
— 
5 So faras the writers have been able to determine, this wheat is unknown in the United States. 
