Lablab: A New Crop for Mid-Atlantic Region of the United States of America

Lablab [Lablab purpureus (L.) Sweet], essentially a tropical plant, is a native of Asia and Africa. It has been a novelty garden plant in the U.S. for generations. Several studies were conducted to characterize productivity of lablab under Virginia's agro-climatic conditions, an area where environmental conditions are not sub-tropical or tropical. From a forage perspective, fresh and dry yields varied from 33 to 121 Mg/ha with a mean of 66, and 7 to 18 with a mean of 13 Mg/ha, respectively during 2011 whereas fresh and dry yields varied from 40 to 93 with a mean of 59, and 7-18 with a mean of 12 Mg/ha, respectively during 2012. Overall means of fresh and dry yields (over years) varied from 47 to 91 with a mean of 62, and 9 to 15 with a mean of 13 Mg/ha, respectively. Concentrations of protein, P, K, Ca, Mg, S, Al, B, Cu, Fe, Mn, Na, and Zn in lablab plant tissue produced in Virginia were 15, 0.28, 2.30, 1.32, 0.27, 0.22, 224, 20, 18, 343, 79, 0.03, and 40, respectively. Lablab seed yields in Virginia varied from 559 (PI 593055) to 1678 (PI 288467) kg.ha-1. The average protein concentration in lablab seed produced in Virginia was 25.4%, with a range from 20.6 to 28.8%, on dry weight basis. The lablab seeds contained small quantities of oil. It varied from 0.54 to 1.13%, dry weight basis, with an average of 0.87%. The sugar concentration in lablab seeds varied from 4.2 to 10.1%, dry weight basis with a mean concentration of 6.2%. Predominant fatty acids in oil of lablab seeds were C18:2 (Linoleic acid: 53.5%), followed by C16:0 (Palmitic acid: 15.8%) and C18:3 (Linolenic acid: 14.1%). Total saturated fatty acids in lablab seed varied from 21.0 to 24.9 % with a mean of 22.2%. Total unsaturated fatty acids in lablab seed varied from 74.8 to 78.9% with a mean of 77.6%. Based on concentrations of Al, P, K, and S (ppm) in lablab biomass (110 to 554, 2400 to 3200, 20300 to 24700, 1900 to 2400, respectively), lablab biomass may also be a potential feed stock for bio-ethanol. One advantage of using lablab biomass as a feedstock for bio-ethanol will be the Symbiotic N Fixation by lablab which could reduce/eliminate use of N fertilizers. It was concluded that lablab is a potential forage and grain crop in mid-Atlantic region of the United States of America.