Component dry masses and carbohydrate contents in honeybush I: Cyclopia genistoides

Abstract

Cyclopia (honeybush), a new and largely unstudied South African horticultural crop, was investigated by carrying out a reconnaissance-level survey of C. genistoides (Cg) populations. Four-year average total dry mass (DM) in plantation-grown Cg cuttings and seedlings, and wild (veld) plants were, respectively, 981, 1 261 and 269 g plant⁻¹. Top growth, thick roots (≥5 mm diameter) and thin roots (<5 mm diameter) constituted 39%, 41% and 20% of total DM in the cuttings, 40%, 43% and 17% in the seedlings, and 51%, 36% and 13% in the wild plants. Total root starch content averaged 13 815 mg (cuttings), 26 771 mg (seedlings) and 5 085 mg (wild plants). Of this starch, 74–80% was located in the thick roots. Thick root:thin root starch content ratios averaged 1.95:1 in the plantations and 3.89:1 in the wild plants, whereas shoot DM:total root DM ratios averaged 0.66:1 in the plantations and 1.03:1 in the wild plants. Starch contents and concentrations were higher between January and March than May to July. To optimise yields and starch contents, Cg should be harvested in autumn rather than summer. Top growth yields per plant in Cg plantations, notably seedlings, exceed those from wild Cg plants.