12 
N. C. Experiment Station 
before they can be stored again. Thus, while the hot water treatment 
greatly diminishes the number of seeds carrying viable elements of the 
anthracnose organism and greatly reduces the incidence of the disease in 
the field, it does not appear that the method can be depended upon to 
completely eradicate seed-borne infection. 
D. Ageing of seed. In 1910 Barre 8 planted seed of the 1908 crop on disease- 
free land and about 10 per cent of the bolls became diseased whereas plants 
from healthy seed remained free. Seed from the same lot was planted again 
in 1911, when less than one per cent of the bolls developed disease. Germi¬ 
nation tests of this same seed revealed no diseased seedlings. This indi¬ 
cates that seeds carrying the anthracnose fungus in a viable condition are 
very few in number by the middle of the third year. In 1916 7 he stated 
that “Three-year-old seed kept in our office and laboratories continued to 
give disease-free plants when planted in the field,” but that “some of the 
seed claimed by farmers to be three years old, and kept in sheds or barns 
did not give such satisfactory results. . . .” 
Edgerton 20 made successive plantings of infected seed in the greenhouse 
and found that no diseased plantlets came from seeds which had attained 
the age of 13 months. Cultures made from seed gave results in harmony 
with those obtained from the greenhouse experiments. The writer’s observa¬ 
tions on this point show that seed of the 1919 crop, germinated in test tubes 
when 9 months old produced seedlings 58 per cent of which were diseased. 
On April 16, 1921, lS 1 /^ months from picking time, 4 per cent of the seeds 
still bore viable elements of the anthracnose fungus. During the nine months 
immediately following picking, these seed were stored in an old barn and 
were for the remaining 9t& months kept in a closed can in the laboratory. 
In another test, seed of the 1921 crop produced 20 per cent of infected seed¬ 
lings when 171/2 months old and 2 per cent when 21 V 2 months old. In two 
tests made with seed which were heavily infected when harvested and which 
were older than 21V 2 months, no disease appeared on the seedlings. It 
should be stated, however, that these seed were stored in the laboratory and 
were not, therefore, subjected to the changes which obtain in gins and barns, 
places where seed are usually stored. In view of these observations, it 
seems probable that, for North Carolina conditions, diseased seed may be 
planted safely in the third season after picking. 
Ageing is the only process yet described for completely freeing infected 
cotton seed from anthracnose. This method has certain objectionable features, 
however, the most obvious of which are: 
1. Storage space must be provided for seed from three seasons’ crops. 
2. It quadruples the required storage period and proportionally in¬ 
creases the losses arising from fire, rains and rodents. 
3. Breeders cannot by this method free their seed from infection with¬ 
out serious loss of time and very great inconvenience. 
Consideration has been given in the above paragraphs to the various 
methods heretofore recommended as helpful in the control of seed-borne 
infection by anthracnose. None of these measures yield thoroughly satis¬ 
factory results under all conditions. There is evident need of a method 
