BIOMASS ACCUMULATION AND ALKALOID CONTENT IN LEAVES OF ERYTHROXYLUM-COCA AND ERYTHROXYLUM-NOVOGRANATENSE VAR NOVOGRANATENSE GROWN IN SOIL WITH VARYING PH

Erythroxylum coca var. coca Lam. (E. cord) and Erythroxylum novagranat ense var. novogranatense (Morris) Hieron (E. nova. novogranatense) wer e grown in greenhouse pots of Monmouth sandy loam, over a pH range of 3.5 through 7.0, to determine patterns for biomass accumulation and th e content of hygrine, tropinone, methyl ecgonine, cuscohygrine, tropac ocaine, cocaine, cis- and trans-cinnamoylcocaine in their leaves. Opti mal growth for E. coca occurred at pH 3.5, and for E. nova. novogranat ense at pH 4.7 through 6.0. The pH extreme (sub-optimal biomass accumu lation, above and below optimal pH) for E. cord was greater than or eq ual to 6.5 and for E. nova. novogranatense less than or equal to 3.5 a nd greater than or equal to 6.5. Hence, E. coca is tentatively termed a calcifuge (Al-tolerant, Fe-inefficient) while E. nova. novogranatens e more nearly resembles a calcicole (Fe-efficient, Al-sensitive). Incr eases in leaf alkaloid content observed at the pH extremes for E. coca and E. novo. novogranatense appeared to be caused by plant stress. E. nova. novogranatense was more tolerant to the high pH extreme than E. coca. Twenty-two months after transplanting, 55% of E. coca plants gr own at soil pH 7.0 died, and those that remained were chlorotic. In ad dition, among E. coca plants grown at soil pH 6.5, only 55% were alive at the third harvest. Cocaine concentration in E. coca was independen t of leaf biomass. Leaves of E. coca grown in soil at pH 3.5 through 6 .0 had higher concentrations of cocaine than those of E. nova. novogra natense. Conversely, leaves of E. nova. novogranatense contained a hig her concentration of trans- and cis-cinnamoylcocaine and methyl ecgoni ne than those of E. coca. The least abundant alkaloid observed in E. c oca and E. nova. novogranatense was tropinone which was low or commonl y not detected. Of the eight alkaloids monitored in leaves of E. novo novagranatense grown in soils at various pH levels, methyl ecgonine wa s the most abundant.