BULLETIN OF THE 
US.lPIffiIOFA«ffill 
No. 38 
Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief. 
November 19, 1913. 
SEED SELECTION OF EGYPTIAN COTTON. 
By Thomas H. Kearney, 
Physiologist, Alkali and Drought Resistant Plant Investigations. 
IMPORTANCE OF KEEPING THE STOCK PURE. 
While questions of picking, ginning, and marketing are doubtless 
uppermost in the minds of most growers of Egyptian cotton in the 
Salt River Valley, they should not lose sight of the fact that the 
industry can not be permanently profitable unless a supply of pure 
seed is maintained. Cotton, like corn, is open fertilized, and the 
pollen is readily carried from one plant to another by bees and other 
insects. Unless due precautions are taken to prevent crossing, the 
varieties soon become mixed and deterioration is rapid. Moreover, 
the most carefully selected stock, even when completely isolated from 
other cotton, produces occasional mi off-type " plants which are in* 
ferior to the average in productiveness and in the quality of the lint, 
Such plants, unless removed, will soon contaminate the entire stock 
and rapid deterioration will follow. Measures to prevent this are 
indispensable if the industry is to be maintained. The highest ob^ 
tainable price for Egyptian cotton depends upon its uniformity in 
length, strength, and other qualities. Uniform land, proper irriga- 
tion, and good ginning all contribute to make the product uniform, 
but these are of little avail if the seed is allowed to run out or to 
become mixed. 
Deterioration of the stock is inevitable if more than one type of 
cotton is grown in a community. This will come about not only by 
the crossing of the plants in the fields but by mixing the seed in 
ginning and handling. The experience of older cotton-growing com- 
munities has proved this time and again. 
The Department of Agriculture, after much consideration of what 
type of cotton would be likely in the long run to give the most profit- 
able returns in the Salt River Valley, distributed among the farmers 
seed of a carefully selected, uniform variety of Egyptian cotton 
which has been developed as a result of 10 years of plant-breeding 
work in Arizona. This variety has been thoroughly tested, both in, 
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