Rotenoid Content and Growth Characteristics of Tephrosia vogelii as Affected by Latitude and Within-Row Spacing1
- D. K. Barnes,
- R. H. Freyre,
- J. J. Higgins and
- J. A. Martin2
Four varieties of the tropical legume, Tephrosia vogelii, a source of the natural insecticide rotenone, were tested for one season at three locations to investigate the effect of latitude and plant spacings on several growth characteristics and on total rotenoid accumulation in the leaves. Planting locations included Mayaguez, Puerto Rico, 18° N; Clemson, S. C., 34° N; and Glenn Dale, Md., 38° N. Planting distances included 1 m between rows and three spacing distances (15 to 23 cm, 30 to 38 cm, and 53 to 61 cm) between plants within the row.
Rotenoid (rotenone and related compounds) accumulation patterns varied among varieties, but the relative rating of varieties for percentage rotenoid content per unit of dry weight was not influenced by planting distance or latitude. Plant growth characteristics such as plant height, leaf-stem ratio, and total yield of stems and leaves were significantly influenced by variety, within-row spacing, and location. Since these growth characteristics are associated with total rotenoid production per hectare, within-row plant spacing which provides 30,000 to 37,000 plants per hectare is suggested as the optimum planting pattern for T. vogelii. Maximum yields of total rotenoids obtained at Clemson, S. C., Glenn Dale, Md., and Mayaguez, P. R., were 82, 104, and 185 kg/ha, respectively.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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