STUDIES ON TREATMENT OF COTTON SEED 
By Samuel G. Lehman 
PREFATORY STATEMENT 
This investigation has, from its inception in 1920, been concerned primar¬ 
ily with the control of cotton anthracnose, although studies have been made 
of a number of other seed-borne diseases. Consideration has been given 
mainly to treatment with dry heat and, as might be anticipated, high tem¬ 
peratures have been found to influence not only the viability of the parasite 
but also the germination of the cotton seed themselves. The study has 
included the influence and interrelationship of the several factors, degree of 
heat, duration of the period of heating and moisture content of the seed, 
on germination, enzymic activity and respiration of the seed and on the via¬ 
bility of the fungus. Since the work on those portions dealing with the 
influence of dry heat on enzymic and respiratory activity is not yet com¬ 
pleted, it is planned to report on them in the near future as separate series 
of these “Studies on Treatment of Cotton Seed” and to include in the pres¬ 
ent papers the completed phases of this work. These data naturally group 
themselves under two general headings, (1) The control of cotton an¬ 
thracnose by the use of dry heat and (2) Germination of cotton seed and 
viability of anthracnose as influenced by desiccation and by storage in 
inert gases. 
ECONOMIC IMPORTANCE OF COTTON ANTHRACNOSE 
Anthracnose of cotton is one of the most destructive of all the diseases 
common to this important plant in the United States. As the result 
of the presence of this disease, cotton growers, breeders and seedsmen 
suffer loses amounting to thousands of dollars annually. Destruction of 
30 to 50 per cent of the bolls in some fields is not an infrequent occurrence 
and cases are known where the losses amounted to 80 or 90 per cent of 
the crop. A fair idea of the amount of loss caused by this disease may 
be gained from a consideration of estimates published by the Plant Disease 
Survey. 28 These figures show that in 1923 all cotton diseases combined 
caused a reduction in yield of 2,439,000 bales in the United States. Nearly 
one-tenth of this loss, or a reduction of 229,000 bales is attributed to 
anthracnose alone. In the same year, the loss to North Carolina cotton 
producers caused by anthracnose amounted to 36,000 bales. These estimates 
do not include the concomitant reduction in yield of seed nor the losses 
arising from the destruction of the stand during the seedling stage. As 
a result of the use of diseased seed, it is often necessary to replant entire 
fields and in consequence to lose valuable time and labor from other urgent 
springtime operations. 
