Schefflera Actinophylla Research Articles

Pathogenicity, Characteristics, and Host Range of the Fungus, Pythium irregulare Buis, in a Container Nursery in Southern California1

Abstract Pythium irregulare was isolated from roots and found to be pathogenic to 4 different hosts showing various disease syndromes in one southern California nursery. The hosts were Dizygotheca elegantissima Vignier & Guill., Brassaia actinophylla Endl. Ilex cornuta Lindl. & Paxt. cv. Rotunda and Nerium oleander Linn. cv. Petite Salmon. One isolate was more damaging on D. elegantissima growing at a mean temperature of 15.5°C than at a mean temperature of 23°C. A bioassay proved that P. irregulare was an inhabitant of the soil at the site of the nursery.

Light Compensation Points and Acclimatization of Four Tropical Foliage Plants1

Abstract Whole plant net CO2 exchange, light compensation points, and acclimatization were determined for Philodendron scandens Subsp. oxycardium (Schott) Bunt, Epipremnum aureum (Linden & Andre) Bunt (Pothos), Brassaia actinophylla Endl. and Dracaena sanderana Sander before and after 4 and 15 week acclimatization periods at 27 μE m−2 sec−1 (400-700 nm), for 12 hr/day. Philodendron scandens Subsp. oxycardium, E. aureum, B. actinophylla and D. Sanderana exhibited CO2 uptake rates of 0.53, 1.16, 1.18 and 0.50 mg CO2 dm−2hr−1, respectively, at 57 μE m−2 sec−l (3400 lx) after 15 weeks of acclimatization. Each species showed a significant increase in net CO2 uptake during the study period. Dark respiration decreased 63% in P. scandens Subsp. oxycardium, 71% in E. aureum, 53% in B. actinophylla and 64% in D. sanderana during the acclimatization period. The regression correlation coefficient of CO2 uptake with light intensity increased for each species during the study. At 15 weeks, P. scandens Subsp. oxycardium, E. aureum, B. actinophylla and D. sanderana exhibited r values of .95, .98, .96, and .91, respectively. Light compensation points decreased between week 1 and week 15 as follows: 33 to 7 μE m−2 sec−1 in P. scandens Subsp. oxycardium, 38 to 6 μE m−2 sec−1 in E. aureum, 14 to 4 μE m−2 sec−1 in B. actinophylla and 119 to 15 μE m−2 sec−1 in D. sanderana. As a result of acclimatization, all species exhibited increases in net CO2 uptake and decreases in dark CO2 evolution concomitantly indicating a reduction in dark respiration. Leaf area increase was negatively correlated with light compensation point. B. actinophylla had the highest leaf area increase with 2.16 dm2, E. aureum and P. scandens Subsp. oxycardium were intermediate with 1.08 and 0.96 dm2, respectively, while D. sanderana, the species with the highest light compensation point exhibited the lowest leaf area increase (0.44 dm2). Philodendron scandens Subsp. oxycardium, E. aureum, B. actinophylla, exhibited similarly rapid rates of acclimatization, while D. sanderana acclimatized much more slowly and had a significantly higher light compensation point.

Acclimatization of Tropical Trees for Interior Use1

Abstract Appearance of container grown Fiscus benjamina Linn. (weeping fig) and Brassaia actinophylla Pov. (schefflera), as measured by plant grade, density and leaf retention after 10 weeks under an interior environment, was improved over plants grown in full sun when plants were previously acclimatized under 40 or 80% shade for 5 or more weeks. There was also an increase in leaf retention as interior light supplied 12 hours/day 7 days a week, increased from 270 to 810 to 1350 lumens/m2.

Comparative Wet-digestion and Dry-ashing of Orange and Schefflera Leaves for Nutrient Determinations1

Abstract Using wet-digestion as a standard, leaf samples of orange (Citrus sinensis (L.) Osbeck cv. Valencia) and Schefflera actinophylla Harms were dry-ashed at 500° and 700°C to demonstrate analytical sensitivity of the Schefflera nutrient elements to ashing temperature. Citrus leaf samples dry-ashed at 500° showed only a significant analytical loss in Fe, but dry-ashing at 700° showed substantial losses in Zn, and K. Schefflera leaf samples dry-ashed at 500° showed substantial losses in Cu, Fe, and Mn. Samples dry-ashed at 700° showed high to very high losses in Ca, Mg, Na, Zn, Cu, Mn, and Fe. Use of an analytical method established for one plant species was clearly not applicable to others without verification.