Influence of rootstock age and gibberellin on the survival rate of clove (Syzygium aromaticum L. Merr. & Perr.) grafting

Abstract

Clove (Syzygium aromaticum) is a cross-pollinated crop with significant genetic variation in planting materials derived from seeds. Vegetative propagation through grafting is a valuable strategy to achieve genetically identical characteristics in progeny. This study investigates the influence of rootstock age and hormone (gibberellin) treatments on the grafting union and survival rate of top clove grafting under greenhouse conditions. The experiments followed a randomized block design with three replications, each con-taining 10 samples, and involving two factors: rootstock age (4, 6, and 8 weeks old) and gibberellin (GA3 ) concentrations (0 and 1 mg L–1). The variables observed include success percentage, survival percentage, number of leaves, chlorophyll content, and examining graft unions through a Scanning Electron Microscope (SEM). The results reveal that 4-week-old rootstocks treated with GA3 exhibited better-grafting plants, with a success rate of 81.33%, survival rate of 56.67%, an average leaf count of 4.56, chlorophyll content of 32.69%, and the absence of cavities in the graft union. This study highlights the importance of rootstock age and GA3 treatment in optimizing clove grafting for enhanced production. GA3 treatment and SEM analysis on the graft union of clove grafting is the novelty of this research.