Improving citrus bud grafting efficiency.

Authors: Niedz, Randall; Bowman, Kim

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2023
Publication Date: 10/18/2023
Citation: Niedz, R.P., Bowman, K.D. 2023. Improving citrus bud grafting efficiency. Scientific Reports. 13, 17807. https://doi.org/10.1038/s41598-023-44832-x.
DOI: https://doi.org/10.1038/s41598-023-44832-x

Interpretive Summary: Commercial citrus trees are composed of a scion, the above-ground part of the tree, grafted onto a rootstock, the below-ground part of the tree. Because grafting is one of the most expensive methods of plant propagation, grafting efficiency is of large practical importance. The purpose of this study was to improve citrus bud-grafting efficiency. The effects of the cytokinin BA, Tween-20, DMSO, water or ethanol, bud cardinal orientation, and supplemental light (LED, metal halide, none) on bud-grafting efficiency were determined using a multifactor design of experiment (DOE) approach. Forty-four different responses were measured and four were selected as useful for identifying treatments of practical value and included the number of rootstock axial buds that formed shoots 13 days after budding, and at 10 weeks after budding the percentage of buds that formed shoots, the length of the longest shoot formed from a bud, and the total leaf area of the bud shoots. The factors driving these responses were no supplemental light to minimize the number of shoots from rootstock axial buds, a south orientation and 5 mM BA to maximize the percentage of buds that formed shoots, a north orientation and 5 mM BA to maximize the length of the longest bud shoot, and 5 mM BA to maximize the area of the bud shoots.

Technical Abstract: Commercial citrus trees are composed of a scion grafted onto a rootstock. Because grafting is one of the most expensive methods of plant propagation, grafting efficiency is of large practical importance. The purpose of this study was to improve citrus bud-grafting efficiency. The effects of six factors that included a BA, Tween-20, DMSO, water or ethanol, bud cardinal orientation, and type of supplemental light (LED, metal halide, none) on forty-four bud-grafting measures were determined using a multifactor design of experiment (DOE) approach. Four measures were considered useful for identifying treatments of practical value and included the number of rootstock axial buds that formed shoots, the percentage of buds that formed shoots, the length of the longest shoot formed from a bud, and the total leaf area of the bud shoots. The factors driving these responses were no supplemental light to minimize the number of shoots from rootstock axial buds, a south orientation and 5 mM BA to maximize the percentage of buds that formed shoots, a north orientation and 5 mM BA to maximize the length of the longest bud shoot, and 5 mM BA to maximize the area of the bud shoots.