Above-ground morphological predictors of rooting success in rooted cuttings of Jatropha curcas L.

Cuttings of 1–3 cm diameter and 45 cm length were collected during the first week of February from branches of previous year’s growth in a mature plantation of Jatropha curcas. The cuttings, without application of any growth regulator, were planted in nursery beds having loam: gravel (1:1 v/v) mixture rooting media. The nursery beds existed inside a polyethylene tunnel where intermittent misting was done. When sprouting percentage had stabilised, sprouted cuttings were removed from the media, and root and shoot characteristics of the cuttings were recorded. The number of roots and root length were found to be significantly correlated (P < 0.01) with one another as well as with sprout length, number of sprouts and number of leaves. The following equations were fitted for prediction of root characteristics of a cutting from of its above-ground characteristics: (i) No. of roots = −0.409 + 0.452 (no. of leaves) + 0.395 (sprout length), and (ii) Root length = 2.656 + 0.206 (no. of leaves) + 0.270 (sprout length); the sprout length and root length are in centimetres in both equations. Thicker cuttings possessed better root and above-ground characteristics.

► Rooting in Jatropha cuttings as a function of above-ground features of cuttings.
► No. of roots = −0.409 + 0.452 (no. of leaves) + 0.395 (sprout length, in cm).
► Root length (in cm) = 2.656 + 0.206 (no. of leaves) + 0.270 (sprout length, in cm).
► Thicker cuttings have better root and above-ground characteristics.