14 
1ST. C. Experiment Station 
does not completely suppress the disease. In the same year, Doran 18 reported 
that heating diseased seed of the garden bean for two hours at 80° C. did 
not give as good control of bean anthracnose as other methods. 
The marked success of the dry heat treatment in the control of cereal 
diseases led the writer to test the efficiency of this method for the elimi¬ 
nation of cotton anthracnose from infected seed. The great reduction in 
anthracnose resulting from the hot water treatment noted above gave 
additional hope that the application of dry heat might prove effective in 
the treatment of diseased seed. Certain preliminary tests were accordingly 
begun in the spring of 1920. While this work was in progress Barre 9 
and his colleagues, Lipscomb and Ludwig, at the South Carolina Experiment 
Station made brief reports on the progress of their studies of the physical 
factors influencing the vitality of the anthracnose fungus carried by diseased 
cotton seed. • In 1919 Lipscomb 9 , 10 , 11 reduced the water content of infected 
seed from 9 to 2 per cent by desiccation in a vacuum and was led to believe 
that this treatment killed the fungus. He also reported that the “fungus 
is killed more readily by a combination of heating and drying than by desic¬ 
cation alone.” In 1920, Lipscomb and Ludwig 10 working with different lots 
of seed and different varieties of cotton were unable to confirm the findings 
of the previous year. In the following year, Ludwig 11 concludes as the 
result of various treatments such as drying in a electrical seed drier and 
hot air oven, sterilizing and storing in various situations, that none of 
these methods may be reled upon to reduce the infection to any marked 
extent. 
In 1923 Lipscomb and Corley 23 , 21 believing that cotton seed could not be 
successfully freed of anthracnose by heating in air because of harmful 
oxidation of the fats and proteins described a method developed by them¬ 
selves whereby seed were subjected to high temperatures in the absence of 
oxygen. A special glass tube was devised within which the diseased seed 
and a quanity of CaCl were sealed in a vacuum of 1 mm. or less or in an 
atmosphere of nitrogen. After they had been allowed to dry, these seed 
were heated in this tube at a temperature of 100° C. for 26 hours. No 
injury resulted to the seed and the anthracnose was completely suppressed. 
Likewise, heating at 110° C. for 10 hours did little or no injury to the 
seed but destroyed all anthracnose. Exposures for periods of 1 and 3 
hours at 110° C. and 1 hour at 120° C. greatly diminished but failed to 
completely eliminate the disease. This method although effective has the 
disadvantage of requiring that the seeds be heated in a vacuum or in 
some inert atmosphere. 
MATERIALS AND METHODS 
This work began in the summer of 1920 with the use of seed from the 
1919 crop. Owing to the tendency of the seed-borne inoculum to lose its 
viability after one year, a new supply of infected seed was obtained each 
season. Cook was the variety used in 1923 and 1924; the names of the 
varieties used in other years are unknown. Fifty per cent or more of the 
seeds of all lots used were shown by tests to carry viable inoculum of the 
anthracnose fungus. 
