14 MISC. PUBLICATION 650, U. S. DEPT. OF AGRICULTURE 
Brazil. Roots for grinding are first air-dried (fig. 8). Then they are 
chopped and oven-dried before being passed into the mill. The final 
product, all of which is 200-mesh, or finer, is packed into bags for ~ 
shipment (fig. 9 and fig. 10). 
FiaguRE 9.—Packing lonchocarpus root for export; Victor Israel warehouse, 
Iquitos, Peru. 
SELECTION OF SUPERIOR-QUALITY STRAINS 
The commercial value of lonchocarpus roots on the United States 
market is determined by their rotenone content, even though insecti- 
cide manufacturers and entomologists recognize the secondary impor- 
tance of the rotenoids. Consequently, the growers of both lonchocar- 
pus and derris are particularly interested in cultivating those strains 
which will yield roots of highest possible rotenone percentage. As 
with many other economic plants, the first major task of selecting 
superior strains from nature’s miscellaneous variety was probably ac- 
complished by primitive man. Perhaps in their search for effective 
fish poisons, the aboriginal inhabitants of the South American rain 
forests discovered and propagated some of the more potent lonchocar- 
pus plants. The majority of contemporary commercial barbascales 
have been established from lines of plants perpetuated by the Indians 
and more recent immigrant settlers. 
When the commercial possibilities of lonchocarpus production were 
recognized both in Brazil and Peru in the early 1930’s, the most enter- 
prising mercantile houses, operating through their rural intermediaries, 
established collections of living plants from the areas where they pur- 
chased the best grades of roots. In Peru a few of these introduction 
gardens eventually expanded into community plantations, where indi- 
vidual families now grow a few acres each and where the total area 
