Effect of rootstock type, scion source and grafting methods on the healing of Allanblackia stuhlmannii grafts under two nursery conditions

Abstract

Allanblackia stuhlmannii, a multi-purpose fruit tree, produces edible oil from seeds, is a new commercial species in global food and cosmetic industry. Cultivation of this fruit tree is limited because of lack quality and quantity planting materials due to poor seed germination. Our study therefore aimed at evaluating healing and survival of scions grafted on two types of rootstocks under two nursery conditions to promote cultivation of A. stuhlmannii by rural farmers. Scions taken from 2 coppiced (L26 and L62) and 3 un-coppiced (L19, L28 and L63) mother sources were grafted on a 2 year-old rootstocks using top cleft, side-veneer grafting and budding methods. Each treatment per site contained 10 seedlings of two rootstocks type (with/without leaves) arranged in a randomized complete block design with nursery sites as blocks (replicates). The grafts take (survival) was assessed 4 months after grafting. The survival rate of the grafts was generally poor in both nurseries. Top-cleft grafting method with scions from coppiced sources produced the best success rate. There was a significant differences on various grafting methods and using scion from coppiced sources, and the interaction of grafting methods and scion sources, p <0.0001. It is presupposed that the low percentile of success (19%) is linked to the physiologic condition of the scions sources, besides less favourable environmental conditions at the time of grafting. The top-cleft grafting method using coppiced scions source proved most effective method in the survival rate of grafts. This method has to be recommended to promote the cultivation of this species