Effect of Planting Date and Plant Spacing on the Rotenoid Production of Tephrosia vogelii in Puerto Rico

Abstract

The effect of within-row plant spacing (approximately 19, 34 and 57 cm.) and time of planting (April 1, April 29, May 27) on rotenoid and seed production of Tephrosia vogelii in Puerto Rico is reported. Percent total rotenoids and seed yield per plant varied among lines, but were not significantly affected by plant spacing and time of planting. Planting date significantly affected time from planting to flowering and proportion of leaves to stem. The April 1 planting date increased number of days to flowering, thereby increasing leaf losses from diseases and senescence as compared to the April 29 and May 27 planting dates. Plant spacing significantly affected plant height, total plant dry weight per hectare and proportion of leaves to stem. Close plant-spacing tended to increase plant height and total dry plant weight, and to lower proportion of leaves. These results indicated that the most efficient crop management system of T. vogelii for Puerto Rico would include a May 27 planting date, with a plant population of about 53,000 plants per hectare. Experimental yields of approximately 280 kg. of total rotenoids or 550 kg. of seed per hectare were obtained from this management system.