Growth behavior and nutritive value of Phaseolus atropurpureus DC. cv. 'Siratro' swards and other tropical pasture legumes

Abstract

Eight introduced tropical pasture legumes were evaluated in first year replicated plots for rate of establishment, dry matter yield, winter survival, crude protein percent (CP%) and in vitro digestible dry matter (IVDDM%) at College Station, Texas. 'Rongai lablab' (Dolichos lablab L.) and 'Centro' (Centrosema pubescens Benth.) were the most productive, having dry matter (DM) yields comparable to 'Siratro' (Phaseolus atropurpureus DC.), which was evaluated previously. 'Silverleaf' desmodium (Desmodium uncinatum [Jacq.] DC.) and 'Greenleaf' desmodium (Desmodium intortum [Mill.] Urb.) became established but produced lower DM yields mostly because of late planting. However, these two Desmodium species have a good potential because of better cold tolerance than other tropical legumes tested. Silverleaf desmodium was the only accession to survive the 1972-73 winter seasons (-10 C to -15 C). 'Townsville' stylo (Stylosanthes humilis HBK.), 'Tinaroo' and 'Cooper' glycines (Glycine wightii [R. Grah. Ex Wigh & Arn] Verdecourt), 'Schofield' stylo (Stylosanthes guyansis [Aubl.] Sw.) appeared to have limited potential. Nutritive value, as measured by percent IVDDM and CP, was satisfactory for Rongai lablab, Centro and the two Desmodium. Average values were approximately 15% CP and 68% IVDDM..