42 
N. C. Experiment Station 
prolonged without danger of reducing germination of the seed. It is an 
effective means by which the loss of time occasioned by the ageing of seed 
may be avoided; for diseased seed which has been properly treated by dry 
heat may safely be planted the season immediately following its production. 
Moreover, the seed grower need not assiduously avoid selection of seed 
from disease-free plants. The dry heat treatment for cotton anthracnose 
described by Lipscomb and Corley not only requires the reduction of the 
water content of the seed by strong preliminary desiccation before the ap¬ 
plication of the high temperature effecting control of the disease but also 
specifies that the seed be heated in a vacuum or in an inert gas, as nitrogen. 
The dry heat method described in this paper has the advantage of being 
less complicated in operation. The use of a vacuum or inert gas is not 
required, the seeds being heated in air after suitable preliminary desiccation. 
By the use of a machine equipped with a proper stirring device, cotton 
seed may be successfully treated in bulk with dry heat. In the opeiation of 
the machine described in this paper, uniform heating is accomplished because 
of very thorough mixing of the seed, and for this reason, this type of 
machine is believed to be well adapted to the treatment of cotton seed 
with dry air at high temperatures. With this machine, the effective treat¬ 
ment for seed in bulk for control of the anthracnose disease without serious 
diminution of germinability consists of 20 to ^24 hours of desiccation at 
GO to 65° C., followed by 12 hours of heating at 95-100° C. 
Practical application of the method of treatment herein described may be 
made by seed companies or associations interested in the production and 
sale of anthracnose-free seed, or by ginners who could treat seed for their 
patrons at a fixed price per bushel. By use of a machine of greater capacity 
than the one used in these tests, much larger quantities of seed can be 
treated at one time. A reliable source of heat is the prerequisite to 
successful operation. In large machines, steam heat could readily be sub¬ 
stituted for electricity and the treatment could be made continuous by so 
constructing the machine that the hot air which has been used to heat the 
seed in the second stage of the treatment can be used to dry seed of a 
second and perhaps even a third lot which is at the same time passing 
through the first or drying stage, in which the aim is merely to reduce the 
water content of the seeds. 
REFERENCES 
1 Appel. O., and Riehm, E. Die Bekampfung des Fliigbrandes von Weizen und Gerste. 
4rb a d K Biol. Anst. Land-und Forstw., Band 8. Heft 3, p. 343-426, t. 1, figs. 2. 1911. 
2 Atanasoff, D„ and Johnson, A. G. Treatment of cereal seeds by dry heat. Jour. 
Agr. Res. Y. 18, p. 379-390. 1920. , 
3 Barre, H. W. Cotton anthracnose. S. C. Agr. Exp. Sta., Bui. 164, p. 1-22. April 1912. 
4 ___Cotton anthracnose investigation. Twenty-second Ann. Rept. S. C. Agr. 
Exp. Sta. p. 89-118. For year ending June 30, 1909. 
-Cotton anthracnose. Report of the botanist and plant pathologist. 
Twenty-seventh Ann. Rept., S. C. Agr. Exp. Sta. p. 20-21. For year ending June 30, 1914. 
a -Cotton anthrocnose. Report of the botanist and plant pathologist. Twenty- 
eighth Ann. Rept. S. C. Agr. Exp. Sta. p. 21-23. For year ending June 30, 1915. 
7 - Cotton anthracnose. Report of the botanist and plant pathologist. 
Twenty-ninth Ann. Rept., S. G. Agr. Exp. Sta. p. 16-17. For year ending June 30, 1916. 
8 .-Cotton anthracnose. Twenty-fourth Ann. Rept. S. C. Agr. Exp. Sta. 
p. 23-42. For year ending June 30, 1911. 
o--- Cotton anthracnose. Thirty-second Ann. Rept. S. C. Agr. Exp. 
Sta. p. 29-31. For year ending June 30, 1919. 
io-Cotton anthracnose. Thirty-third Ann. Rept. S. C. Agri. Exp. Sta. 
p. 35-36. For year ending June 30, 1920. 
