Effects of Leaf Reserved and clipped on Axillary Bud Quality in Umbrella-Shaped Hevea brasiliensis ‘Reken 628’ Bud-sticks

Abstract

The insufficient supply of bud-sticks from traditional single-stem rubber trees (Hevea brasiliensis) remains a bottleneck for mini-seedling budding in commercial rubber plantations. To address this issue, we investigated the impact of leaf reserved versus leaf clipped on axillary bud development in umbrella-shaped ‘Reken 628’ rubber trees. After removing apical dominance by topping, the plants developed multiple branches, yielding 4–6 times more bud-sticks than conventional methods. Bud-sticks were harvested when petioles detached naturally and leaf scars turned brown. Axillary buds (scale buds and petiole buds) from the second (2nd) and third (3rd) leaf whorls were analyzed for quantity, moisture content, and morphological traits (bud scar dimensions, bud eye size). :Leaf reserved 2nd buds exhibited superior quality, with significantly higher moisture content (9.40–10.69%), larger bud scar width (43.21%), and thicker bud scars (19.69%) compared to their clipped counterparts (P < 0.05). Leaf-clipped reduced physiological consistency, increasing variability in leaf length (CV: 21.40–25.86%), leaf width (20.79–23.36%), and stem moisture (5.89%). Correlation analysis revealed strong synergies between leaves reserved, stem thickness, and bud moisture, critical for grafting success. We conclude that reserved leaves on 2nd whorls of umbrella-shaped trees optimizes bud-sticks quality for mini-seedling budding. Post-topping management should prioritize frequent irrigation and balanced fertilization to sustain nutrient supply. This strategy enhances bud-sticks yield, grafting efficiency, and survival rates, offering a scalable solution for high-demand rubber nurseries.