THE WORLD'S COTTONS — HUTCHINSON 507 



Africa are now Uplands. In India and Pakistan, Upland cottons 

 were first introduced at the time of the American Civil War. They 

 were a dismal failure, owing to the attacks of the jassid pest. Upland 

 cottons went out of cultivation as a crop, but persisted as occasional 

 plants in crops of Old World cottons. Under the shelter of the Old 

 World types. Upland types were not altogether eliminated, but those 

 with some of the leaf hair that gives resistance to jassid attack were 

 favored. Fifty years later, it was possible for agricultural botanists 

 to select, from the mixed crops, Upland types that had sufficient 

 resistance to be grown satisfactorily in pure stands. This was the 

 beginning of the successful establishment of Upland cotton as a crop 

 in India. A different source of American-type cottons for use in 

 India was discovered in the second decade of the 20th century. 

 Madras cotton-spinners drew the attention of Government botanists 

 to a very useful type of cotton they had been able to import from 

 Cambodia. Seed was obtained, and became the foundation stock of 

 what is now known as the Cambodia crop of South India. Cambodia 

 is a latifolimn type; its outstanding characteristic is the extremely 

 dense coat of long hairs on the leaf, which gives it very high resistance 

 to jassid. It appears to have been derived from direct introductions 

 by the Spaniards from Central America to the Philippines. The 

 Central American cottons are short-day plants, and when grown in 

 the long summer days of northern latitudes they do not fruit until 

 autumn, and consequently they lose their crop when the frost comes. 

 The establishment of the Uplands in the United States depended on 

 the selection of types tolerant of long days and able to mature a crop 

 before the onset of cold weather. Consequently, Upland cottons, 

 wherever they have been taken, are unaffected by day length. The 

 Cambodias, on the other hand, though early fruiting in the short days 

 of Madras, become progressively later- fruiting as they are taken far- 

 ther north, and have in consequence never been successful in com- 

 petition with Upland types in central or northern India or Pakistan. 



The latifolium cottons have become the dominant cottons in the 

 world's crop. United States commercial varieties of Upland have 

 formed the basis of the cotton crops of Africa, of most of South 

 America, and increasingly of Central America. Uplands and Cam- 

 bodias are invading the Chinese crop, and where cotton crops are 

 developed in southeast Asia, they will undoubtedly be based on these 

 types, and on hybrids between them. 



The development of annual cottons in G. harhadense took place 

 later than in G. hirsutum. The hai'hadense cottons of the Sea Islands 

 of South Carolina arose from an introduction from either the 

 Bahamas or Jamaica in 1786. In the Sea Islands only annual cropping 

 was possible, and so the type introduced must have been one that was 

 already capable of producing a worth-while crop in the first year. 



