The Increase in Kaffir Lime Leaf Production Due to Gibberellin Is Diminished by Pruning

Abstract

Gibberellin regulates the flowering and fruiting response of fruit-oriented citrus, but there are a lack of studies on the methods for boosting the production of leaf-oriented citrus. This study aimed to analyze the effects of exogenous gibberellins and pruning on the leaf production of kaffir lime. Kaffir lime seedlings, grafted into rangpur lime, were arranged in a split-plot design under an open field condition. Four gibberellin concentrations (control, 0.005%, 0.01%, and 0.02%) and two pruning levels (no pruning and pruning at 30 cm main stem) were subjected to selected seedlings. The result showed a contrasting effect between gibberellin and pruning on the plant height and shoot number. Pruning significantly reduced the flush number, flush length, leaf length, leaf area, and leaf weight by 38%, 44%, 17%, 26%, and 28%, respectively. Without pruning, applying 0.02% gibberellin could produce the longest flush, with an increase in the number and weight of leaves by about 77% and 64%, compared with the control, respectively. Multivariate analysis also confirmed the positive effect of gibberellin on leaf production. However, these positive results are diminished by pruning due to limited source capacity, as indicated by the fewer leaves. Future research is required to analyze whether increasing gibberellin concentrations can speed up the recovery of post-pruned kaffir lime.