An Evaluation of Factors Influencing Successful Grafting of Breadfruit on Chataigne Rootstock

The potential for expanding the availability of breadfruit (Artocarpus altilis) as a food source in the Caribbean by establishment of commercial orchards is limited by its being vegetatively propagated. One of the disadvantages of this propagation method is a shallow rooting system, which results in limited distribution of the tree mainly to wetter regions, susceptibility to root-inhabiting diseases and proneness to hurricane damage. Chataigne (A. camansi), a close seed producing relative, produces a tap root and exhibits these disadvantages to a lesser extent. Therefore, grafting breadfruit on chataigne can potentially benefit commercial establishment. Poor success in grafting these species has been reported. This experiment aimed to evaluate the effect of grafting techniques, scion cultivars and ages of rootstock on grafting success. Grafting techniques were top wedge, side, and whip and tongue; the scions were the 'Yellow' and 'White' breadfruit cultivars and chataigne and ages of chataigne rootstocks were 47, 67and 130 days old. A threefactor, factorial arrangement in a complete random design was used with 10 plants per treatment. Data were collected on the condition and length of survival of grafted scions and analysed using ANOVA, General Linear Model. Variety was the only factor with significant (p < 0.001) effect on success of grafting. Six weeks after grafting, there was 71% survival of grafts of chataigne scion grafted on chataigne rootstock, compared with 28% of 'Local Yellow' scion and 18% of 'Local White' breadfruit. The results suggest a genetic influence and a possible physiological effect on the success of grafting.