184 ANNUAL REPORTS OF DEPARTMENT OP AGRICULTURE. 



diiction of henequen fiber in Yucntan during tlie same period. Com- 

 paratively little of the l*hilippiiie liber was machine cleaned, for 

 very few of the new machines ordered have been installed ready 

 for operation, but it indicates that a production of considerable 

 propoi'tions may be expected with the added impetus of machine 

 clean in<^. 



In the Dominican Republic our investigations, including a small 

 trial planting, have resulted in the preparation of plans and the 

 beginning of actual work for a large commercial plantation of 

 henequen. 



In Porto Rico 600,000 sisal plants have been set out on one plan- 

 tation, to which many thousands are being added each year, while 

 the earliest ones have reached the stage of fiber production, and two 

 other commercial plantations are being started. 



The development of improved strains of sisal and henec^uen by 

 selection in Porto Rico, begun in 1917, is showing very promising 

 results. Marked differences arc observed in the progenies of dif- 

 ferent selected parent plants, while the bulbils and suckers of all 

 appear to be superior to the average unselected stock. Some of these 

 plants are being set out in commercial plantations for comparison. 



HEMP. 



The relatively high prices for other crops, combined with the 

 scarcity of farm labor, has brought about a decrease in the acreage 

 of hemp, especially in Kentuck}^, where the fiber is broken out and 

 hacklecf by hand. An important limiting factor in hemp cultivation 

 during the last two years has been the insufficient suppl}'^ of seed of 

 good quality. Efforts are being made to encourage hemp-seed pro- 

 duction in new areas, and trials are being made this season (1920) at 

 several points in Missouri, Texas, and California, while seed of im- 

 proved strains has been furnished to the hemp-seecl growers in 

 Kentucky to encourage increased production there. 



The work of breeding improved strains of hemp is being con- 

 tinued at Arlington Farm, Va., and all previous records for height 

 of plants, either individual or average for plats, were broken in the 

 selection plats of 1919. The three best strains, Kymington, Ching- 

 ton, and Tochimington, averaged, respectively, 14 feet 11 inches, 15 

 feet 5 inches, and 15 feet 9 inches, while the tallest individual plant 

 was 19 feet. The improvement by selection is shown not alone in 

 increased height but also in longer internodes, yielding fiber of better 

 quality and increased quantity. 



Seed of these pedigreed strains has been sent out to hemp-seed 

 growers, as in former j^ears, increasing each season the proportion of 

 hemp of improved varieties. 



FLAX. 



The price of flax fiber is relatively higher than that of any other 

 vegetable fiber on the market, being at present four to five times the 

 prewar quotation. This is due to the fact that the supplies from 

 Russia, formerly 80 per cent of the world's production, are now al- 

 most completely cut off. The 6,000 acres devoted to fiber flax in 

 Michigan, Wisconsin, Minnesota, and Oregon in 1920 show an in- 



