BULLETIN OF THE 



UMiTTOAMIII 



No. 38 



Contribution from the Bureau o c Plant Industry, Wm. A. Taylor, Chief. J 

 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 "' 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 Eiver 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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