FIBER FROM DIFFERENT PICKINGS OF EGYPTIAN COTTON. 1 



By Thomas H. Kearney, Physiologist in Charge of Alkali and Drought Resistant Plant 



Investigations. 



INTRODUCTION. 



Two pickings were made from the individual selections of the 

 Yuma variety of cotton at Sacaton, Ariz., in 1911, the first early in 

 October, the second about a month later. The first picking consisted 

 largely of the first bolls which open on the plants, these being borne 

 principally on the lower fruiting branches of the main stem. The 

 development of these lower bolls is frequently checked by the heavy 

 shading to which the lower part of the plant is subject in this variety. 

 Practically all of the bolls included in the first picking had matured 

 and opened during the hot weather in September. The second, or 

 November, picking took in the cotton from bolls which were more 

 favorably situated on the plants (nearer the tops) and which had 

 matured during the cooler weather of October. 



At Bard, Cat., in 1911, the first cotton in the progeny rows of the 

 Yuma variety ripened so early that these rows were picked in bulk 

 about the middle of September, before individual selections had been 

 made, thus eliminating the cotton which was included in the first 

 individual picking at Sacaton — that from the early-opening bolls 

 near the bases of the plants. For this reason, it would be expected 

 that the cotton of the two pickings made from the individual 

 selections would show less difference at Bard 2 than at Sacaton. A 

 comparison of the fiber from the two pickings of each individual plant 

 at Sacaton and at Bard, respectively, proved that this was the case. 

 No differences in length, strength, and abundance (lint index) of fiber, 

 or in weight of seeds, could be detected in samples from the two pick- 

 ings at Bard. The conclusions herein reached are therefore based 

 solely upon the material collected at Sacaton. 



i Issued Jan. 18, 1913. 



2 At Bard the first picking of individual selections was made about October 15, the second at the end of 

 November. 



[Cir. 1101 37 



