Growth of lucerne in response to height and frequency of defoliation

Abstract

Lucerne has generally been reported to decline in productivity with increasing intensity of utilization. Considerable evidence is available to show that both frequency and height of cutting determine subsequent yield (e.g. Peterson & Hagan, 1953; Ridgman, 1960; Kust & Smith, 1962; Cowett & Sprague, 1962), but few reports on the interrelationship of these two components of management have so far come to hand, nor are we adequately informed on the influence of defoliation on the roots and its attendant effect on top growth. Precise information on these aspects has become a matter of urgency, if the production potential of lucerne is to be understood as clearly as that of rye-grass/white clover (Brougham, 1956) or of subterranean clover swards (Donald, 1961). To this end we have conducted experiments on the combined effect of cutting height and frequency on lucerne grown in pots, subsequently to be extended to field investigations.