Treatment of Cotton Seed 
9 
bods and produces more or less discoloration or even complete decay of 
both fiber and seeds. Individual bolls may fail entirely to open or if less 
severely attacked only a part of the locks may open. In such cases, the 
lint is frequently so badly discolored or so firmly matted together as to be 
worthless. Even when infection is so slight as to produce no apparent 
discoloration, the microscope will reveal the presence of the fungus fila¬ 
ments among the fibres and within the tissues of the seed. 
NATURE OF THE SEED-BORNE INFECTION 
By the planting of infected seed, it is easily demonstrable that the fungus 
which causes cotton anthracnose is carried from season to season on the 
seed. This fact may be established by germinating on sterile blotters seed 
v.liich came from diseased bolls. Some or all of the seedlings will develop 
anthracnose lesions on cotyledons or liypocotyl, whereas seed from uninfected 
bolls will produce healthy seedlings only. A large portion of this inoculum 
is caiiied in the form of spores and mycelium in the fuzz on the surface 
of the seed. If diseased seed which have been delinted with sulphuric acid • 
are germinated it is found that the percentage of diseased seedlings is 
very much less than that obtained by germinating, untreated seed from 
the same source. However, the most severe treatment with surface disin¬ 
fectants will not kill all the seed borne elements of this disease. This 
situation indicates that the fungus causing anthracnose must be carried in 
part within the seed. Barre 3 has described and clearly illustrated 
this condition by drawings made from sections of diseased seeds which 
show that the mycelium penetrates the seed coat and invades the tissues 
of the embryo often sporulating on its surface. Here it remains in a 
dormant but viable condition throughout the winter and starts into active 
growth when the seeds germinate in the following spring. Any seed treat¬ 
ment, therefore, which is directed toward the control of cotton anthracnose 
must reckon with the the internal nature of the infection in order to attain 
any satisfactory measure of success. 
METHODS COMMONLY RECOMMENDED FOR CONTROL OF 
ANTHRACNOSE 
A. Seed selection. Field selection of seed is a practice which cannot 
be too highly recommended as a matter of general farm procedure. It 
is advisable from an agronomic as well as a pathological point of view. 
Very encouraging results have been obtained in the control of cotton 
anthracnose by taking seed from plants which bear no diseased bolls 
and which are not adjacent to other diseased plants. By selecting seed 
from healthy plants in a field where 20 per cent of the bolls were infected 
Barre 3 obtained a crop free from anthracnose, whereas the crop from 
unselected seed from the same field was abundantly diseased. However 
when the average person, whose eye is not trained to recognize infections 
of an incipient or minor nature, makes the selections, a small amount of 
diseased seed is liable to be included unwittingly. Moreover, in cotton 
breeding operations small plots representing strain or type selections 
may become diseased as the result of wind or insect borne spores from 
