Some Effects of Altitude and Water Supply on the Composition of Derris elliptica

1. Derris elliptica was grown in Puerto Rico at elevations ranging from 50 to 2400 feet above sea level and in Guatemala at altitudes ranging from 910 to 4888 feet. 2. The temperature factor of altitude correlated positively with rotenone and inversely with reserve carbohydrates in derris roots. 3. At elevations favorable to growth of derris plants, the accumulation of rotenone was influenced by major variations in water supply, but reserve carbohydrates were altered by relatively minor variations in available moisture. 4. The varietal selection of Derris grown in Guatemala appeared to be more adapted to higher elevations, in an ecological sense, than the Sarawak Creeping variety grown in Puerto Rico. 5. The normal effect of age on the percentage of rotenone was apparently obscured at high altitudes. 6. Soil pH, ranging from values of 4.7 to approximately neutral, had no measurable effect on rotenone or carbohydrate reserves. 7. At favorable altitudes, derris plants flourished in soils having good physica...