The relationships between fertilizer levels and vegetative growth of ' Passiflora biflora' were investigated. Optimum levels of fertilization with 20-20-20 were 446 ppm, 466 ppm, and 406 ppm N for leaf area and leaf and stem dry weight respectively. Leaf area and leaf dry weight were maximized at 330 ppm N from 20-20-20, and stem dry weight increased linearly with increased fertilizer rate. Leaf area and leaf and stem dry weight were maximized N levels of 405 ppm, 342 ppm, and 400 ppm respectively. Irradiance, temperature, humidity, and CO2 were also examined to determine the optimal environmental conditions for 'P. biflora' vegetative growth. At ambient CO2 and 25°C, whole plant net carbon exchange rates (NCER) reached light saturation above 1010.13 [mu]mol m-2s-1 photosynthetically active radiation (PAR). At 25°C and 500 [mu]mol m-2s -1 PAR whole plant NCERs reached saturation above 1000 [mu]l l-1 CO2. Humidity levels did not effect whole plant NCERs at 25°C, ambient CO2, and 1000 [mu]mol m -2s-1 PAR. Defoliation of 'P. biflora' was investigated in order to determine the effects on regrowth. Leaf area of regrowth foliage was maximized at 71.6% defoliation. 'Heliconius' butterfly larvae were fed leaves of ' P. biflora' that were fertilized with either 50, 200, or 400 ppm N. There were no significant differences among treatments for final larvae length or weight, or pupae length or weight. (Abstract shortened by UMI.)