Root Formation on Cuttings of Camellia reticulata var. ‘Capt. Rawes’

Abstract

MOST camellias will form roots readily on cuttings, but the C. reticulata cultivar, ‘Capt. Rawes’, is a notable exception. Failure to induce roots in cuttings of this camellia, despite the use of modern techniques such as growth regulators, etc., has led to the belief that it is unable to form roots, and several reasons have been put forward to account for this. It may be due to anatomical features, such as fibre, creating mechanical resistance¹ or the presence of inhibitors which prevent root formation² or the absence of some internal factor which is essential for root formation. Went³ first postulated the presence of such a factor which he termed ‘rhizocaline’, but the presence of a single substance of this nature has never been demonstrated. Hess⁴ has shown, however, that certain substances which are present in the juvenile form of Hedera helix, but absent in the mature form, could account for the failure of the mature form to initiate roots on cuttings. He has described these substances as ‘co-factors of rooting’.