Effects of defoliation intensity on white clover seedling growth

White clover seedlings were defoliated when either two, four or six leaves had opened. There were four defoliation treatments, involving removal of younger laminae, older laminae, all laminae or all laminae and petioles, plus a control (no defoliation). Leaf removal reduced area of subsequently emerging leaves when measured as they became fully opened, though some compensatory expansion occurred after this. Petiole length was also reduced considerably. The magnitude of these effects varied according to severity of the treatment: removal or older laminae had little effect, removal of younger laminae had a similar effect to removing all laminae, but the effect was considerably increased by removing petioles in addition to laminae. The youngest plants showed the greatest reductions in leaf size following leaf removal. Defoliation had little effect on the rate of development of subsequent leaves. The most severe defoliation treatments reduced plant dry matter but younger seedlings appeared to have a capacity for recovery equal to or greater than that of older seedlings. It is concluded that white clover seedlings have a considerable ability to recover from leaf removal, especially if only laminae of old leaves are removed, but the growth reduction following removal of petioles as well as laminae appears to be especially severe.