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Above ground dry matter production (DM) of Medicago truncatula, cvv, Cyprus and Jemalong, M. aculeata var. inermis, cv. SA 4438, M. orbicularis, cv. SA 2552 and M. rugosa, cv. Paragosa, established on six different dates, was determined in an irrigated field trial. The planting date were spaced c. 15 days apart, from mid February until the end of April, DM was determined at three stages, namely three weeks after emergence, the beginning of flowering and the onset of pod colouring when the approximate peak DM was reached. Eventually pod and seed yields were also determined.

At three weeks a progressive reduction in DM was recorded with later planting, which was ascribed to the associated drop in temperature. The yields at flowering and pod colouring, on the other hand, were largely determined by the time lapse from establishment until the specific stages were reached. The mean peak DM production over the six plantings were 11,5; 10,7; 8,4; 6,7 and 5,0 t/ha for Jemalong, SA 4438, Cyprus, Paragosa and SA 2552 respectively. Mean seed yields varied from 650kg/ha in Paragosa to 2460 kg in SA 2552.