Delayed rooting hormone application and stem cutting collection time improved Flacourtia indica rooting ability and root growth

Abstract

Flacourtia indica (Burm.f.) Merr. is an important fruit and medicinal tree in Southern Africa. Efforts to achieve early fruiting have failed with juvenile propagules (planting materials) such as seed. Assessing rooting ability of mature (fruit bearing) F. indica stem cuttings is vital to attaining early fruiting, or precocious fruiting, which reduces the long juvenile phase experienced by many woody fruit trees when propagated from seeds (juvenile planting materials). The objectives of this study were to assess responses of mature stem cuttings to different application times of rooting hormone (Seradix^® No. 2) and collection times of stem cuttings, and also to identify important pheno-phases in the yearly tree growth cycle of F. indica. A significantly higher rooting percentage (p < 0.001) was obtained with delayed Seradix^® No. 2 application than with immediate application. Stem cuttings collected at flowering and leaf fall seasons were responsive to Seradix^® No. 2 application, but all stem cuttings collected at fruiting time failed to produce roots. For stem cuttings collected during flowering time, immediate Seradix^® application resulted in significantly (p = 0.0482) more roots than in stem cuttings subjected to delayed Seradix^® application. The failure to produce roots of cuttings collected at fruiting time could be due to low sugars (carbohydrates) in the stem cuttings. The study concluded that the best time to collect stem cuttings from mature F. indica trees for rooting is either at flowering or leaf fall stages and that delayed Seradix^® No. 2 application improves rooting of stem cuttings from mature F. indica trees.