174 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Possibilities of maintaining sea-island cotton. — It has been as- 

 sumed by many that the culture of the superior sea-island cotton 

 of South Carolina could not be maintained in the presence of the 

 boll weevil, but experiments are being made for a more definite 

 determination of this question, and more information may lead to 

 a different conclusion. It seems not impossible that the difficulties 

 arising from the later maturity of the sea-island crop and its greater 

 susceptibility to the boll weevil may be prevented by changes in 

 cultural methods and through better organization of the industry, in 

 order to avoid the planting of upland cotton in the same com- 

 munities and thus defer the breeding of boll weevils too early in 

 the season. The need of very early planting of sea-island cotton is 

 avoided and a much shorter period of production made possible by 

 closer spacing of the plants combined with rather late thinning, to 

 ^ get full exposure of the soil to the sun and facilitate the collection 

 of weevil-infested squares when the weather is not dry enough to 

 kill the weevil larvae. A method that may prove useful under sea- 

 island conditions is to plant in hills 15 inches apart, thinning to 

 two plants when about 8 or 10 inches high, or after the first squares 

 begin to form. The sea-island bolls are more delicate and suffer 

 worse from the weevils, but possibly they can be protected by the 

 use of poison or in other ways. 



Cotton varieties in Central America. — An agricultural exploration 

 in British Honduras and the adjacent districts of the Department 

 of Peten, Guatemala, the region of the ancient Maya civilization, 

 has resulted in the discovery of a series of additional forms of cotton 

 quite different from any that have been recognized in other parts of 

 Central America, but bearing a certain resemblance to the native 

 cotton varieties of our Southwestern States as grown formerly by 

 the Pima and Hopi Indians. Though having a general relationship 

 to the upland cottons of our Southern States, the Peten and British 

 Honduras cottons are distinct in numerous characters. The seeds 

 as well as the bolls are much smaller, though the lint is of good 

 length and quality, and the plants are prolific and possibly resistant 

 to drought. The severity of the dry-season conditions in this region 

 may account for the absence of the boll weevil, which was not found 

 on any of the native cotton in this district, unlike the neighboring 

 Department of Alta Vera Paz, Guatemala, VN^here weevils are known 

 to exist.' 



Egyptian cotton breeding. — Cooperation with the associated 

 growers of Pima cotton in the Salt River Valley, Ariz., in main- 

 taining a supply of pure planting seed has been continued. The 

 introduction of other types of cotton in this community has in- 

 creased the importance of close attention to the seed supply. Ex- 

 perimental evidence has been obtained that the Pima variety has 

 remained unchanged genetically and has suffered no loss of uni- 

 formity since the first commercial plantings were made in 1916. 

 Occasional complaints by consumers of increasing variation in the 

 fiber are unquestionably attributable to increased diversity in the 

 soil and in cultural practices resulting from the expansion of the 

 acreage. 



Breeding work with the Egyptian type of cotton is being continued 

 with the objects of developing a more productive and smoother 

 seeded strain of the Pima variety and of combining by hybridiza- 



