16 MISC. PUBLICATION 650, U. S. DEPT. OF AGRICULTURE 
Smith, is the principal lonchocarpus species cultivated in Peru, prac- 
tically all 274 collections made from major producing areas on the — 
Marafion, Huallaga, and Amazon Rivers consisted of this type. Sub-. 
sequent chemical analyses of the roots revealed a range in rotenone 
content from less than 1 to a high of 6.59 percent. The air-dry-root 
weights of 32 plants, 24. years old, ranged between 147 and 789 grams. 
Of nine 5-year-old plants, the lowest air-dry-root weight was 705 grams 
and the highest 1,620 grams. 
During the years 1944 and 1945 Peruvian technicians attached to 
the Estacién Experimental Agricola de Tingo Maria made several 
hundred additional lonchocarpus collections from other important com- 
mercial growing areas in eastern Peru. Cuttings from these plants 
were set out in introduction gardens, and their roots are now being 
analyzed. As at the Instituto Agronomico do Norte in Belém, the 
objective of the Peruvian investigations is to establish and increase 
clones of lonchocarpus which can be distributed to commercial growers 
for more profitable production. Similar research is being undertaken 
at the Estacién Experimental Agricola del Ecuador at Pichilingue on 
the Vinces River. 
DERRIS 
Prior to the recent war derris roots grown principally in British 
Malaya, the Netherlands East Indies, the Philippine Islands, and 
Formosa constituted the main source of the world’s rotenone supply. 
Derris plants have been introduced into most of the tropical countries 
of the Western Hemisphere, but as yet they have not achieved com- 
mercial importance. Recently, however,some excellent high-rotenone- 
yielding clones were acquired which may contribute materially to 
advancing derris as a commercial crop in the American Tropics. Far 
more experimental research has been conducted on derris than on 
lonchocarpus. Most of these investigations were made in Puerto 
Rico, the Netherlands East Indies, and in British Malaya. 7 
Several species of derris are known to contain rotenone, but only 
Derris elliptica and, to a lesser degree, D. malaccensis remain com- 
mercially important. In the Federated Malay States, the principal 
exporter of derris, the varietal types of D. elliptica include not only 
the popular Sarawak Creeping and Changi No. 3 but also, among 
others, the Singapore Nos. 1 and 2 and the Changi Nos. 1 and 2 (88). 
The Sarawak Creeping possesses considerable vigor and has a wide 
tange of adaptability, whereas certain clones of Changi No. 3 are 
superior in rotenone percentage and also develop well under favorable 
environmental conditions. A few varieties of D. malaccensis, including 
the Sarawakensis or Sarawak Erect, Tuba Merah, and Kinta Type, 
have been cultivated in the Federated Malay States, even though their 
content of rotenone is reportedly small, because their roots contain 
high percentages of rotenoids. The market value of these is low, com- 
pared with that of the best D. elliptica varieties, which are sold on a 
rotenone-content basis. 
VARIOUS CULTURAL PRACTICES 
Native growers and agricultural experiment stations have developed 
a number of different methods of derris culture, which are reviewed by 
