Kearney: A Plant Industry Based upon Mutation 



53 



inches, hence most Egyptian cotton 

 falls into the long staple class ( lys inch 

 or longer). The longest Egyptian cot- 

 ton is surpassed in length only by the 

 best Sea Island. 



COTTON CROP OF EGYPT 



The cotton crop of Egypt amounts to 

 500 or 600 million pounds annually, 

 which is approximately one-tenth of the 

 average production of the United States. 

 The best qualities are grown in the 

 Delta, the cotton of the Nile Valley 

 above Cairo being inferior in the quality 

 and length of the fiber. The crop is 

 grown entirely under irrigation. 



Cotton is exported from Egypt to 

 of the principal spinning countries. The 

 United States imported last year about 

 100 million pounds of this cotton. 

 Egyptian cotton is in great demand 

 for the manufacture of goods requiring 

 a high degree of tensile strength, such 

 as sewing thread, durable hosiery, and 

 automobile tire fabrics. 



The Department of Agriculture, about 

 twenty years ago, began experiments to 

 determine whether Egyptian cotton 

 could be grown in the United States. 

 Several introductions were made, the 

 most important by Mr. David Fairchild, 

 who visited Egypt in 1899 and obtained 

 seed of the principal varieties then 

 grown in the country. This seed was 

 tested by Dr. H. J. Webber at a number 

 of stations in the southern and south- 

 western states. For various reasons it 

 was concluded that commercial produc- 

 tion in the main cotton belt would be 

 impracticable, but on the irrigated 

 lands of the southwest the results were 

 so promising as to warrant further 

 experimentation. ^ 



SELECTION NECESSARY 



The behavior of the plants grown 

 from imported seed made it evident, 

 however, that selection would be neces- 

 sary in order to obtain a sufficiently 

 fruitful, early, and uniform stock to 



justify commercial production. All of 

 the varieties, when first introduced, 

 were not only relatively late ripening 

 and unfruitful (Fig. 1), but were also 

 extremely variable. This lack of uni- 

 formity, as was later pointed out by Mr. 

 0. F. Cook, was due to the fact that the 

 conditions under which cotton is grown in 

 Egypt, favor unlimited cross-pollination 

 in the fields and mixing of seed at the 

 gins.* The most serious contamination 

 was due to the abundant presence, as a 

 weed, in Egyptian cotton fields, of the so- 

 called "Hindi." This is a very inferior 

 type, more nearly related to American 

 Upland than to Egyptian cotton, but 

 hybridizing freely with the latter.^ 



EXPERIMENTS BEGUN AT YUMA 



Plant breeding experiments were 

 begun by the writer at Yuma, Arizona, 

 in 1903 with MitAfifi, the variety which 

 at that time was most extensively grown 

 in Egypt. Selection was carried on for 

 several years, resulting in a gradual im- 

 provement in the uniformity, earliness 

 and productiveness (Figs. 1 and 2) in 

 the manner in which the bolls opened 

 (Figs. 3 and 4) and in the length of the 

 fiber (Fig. 5). Up to this point, no 

 marked change of type was observed to 

 have taken place. 



A new era in the breeding work began 

 in 1908 when two of the progeny rows 

 were found to differ strikingly from 

 the parent stock and from one another. 

 These rows gave rise to the Yimia and 

 Somerton varieties . The latter was soon 

 discarded because of its excessive develop- 

 ment of vegetative branches or "limbs," 

 but the Yuma variety was preserved 

 and became the basis of the Egyptian 

 cotton industry in Arizona . This variety 

 differed from the parent Mit Afifi in 

 numerous characters, of which the most 

 conspicuous were the longer and more 

 pointed bolls (Fig. 6) and the longer 

 (about 13^ inch) and lighter colored 

 fiber (Fig. 5). 



A third variety, the Gila, was 



* A year or two prior to the commencement of experiments in the southwest by the Depart- 

 ment of Agriculture, Egyptian cotton was grown at Phoenix by the Arizona Agricultural Experi- 

 ment Station and large yields were obtained. . 



* The Government of Egypt has recently taken measures looking to the mamtenance of 

 supplies of pure seed. „ . ^./^ /<r.<<\ 



* Cook, O. F. Hindi Cotton in Egypt. Bureau Plant Industry Bulletm 210 (1911). 



