Beyond growth and yield: grafting reshapes nutrient acquisition, transport, and utilization in dwarf cashew clones

The use of grafted seedlings has led to significant changes in the dwarf cashew cultivation system, resulting in homogeneous plants with early fruit production. Although grafting is widely used in dwarf cashew propagation, its effects on nutrient absorption, transport, and utilization efficiencies remain poorly understood. Therefore, the objective of this study was to evaluate the influence of grafting on the efficiency of absorption, transport, and nutrient utilization by dwarf cashew clones. The experimental design was a randomized block design in a 3 x 3 factorial scheme, with three clones of dwarf cashew (‘CCP 06’, ‘CCP 76’, and ‘BRS 226’), three types of seedlings (non-grafted, self-grafted, and BRS 189-grafted), and three replicates. Grafting dwarf cashew seedlings promoted changes in nutritional efficiency. Compared to seed-propagated seedlings (non-grafted), grafting with the same clone (self-grafted) or with a clone different from the rootstock (‘BRS 189’) increased P, K, Ca, Mg, and Cu absorption efficiency and K, Mg, S, Cu, and Zn transport efficiency. In contrast, grafting reduced nutrient utilization efficiency, with Ca showing the greatest reductions (66.1-75.0% across clones), whereas N was comparatively less affected (44.3-53.2%). Overall, the effects of grafting on nutritional efficiency depended on the nutrient and scion-rootstock combination. These findings demonstrate that grafting modifies nutrient absorption, transport, and utilization in dwarf cashew seedlings and highlight the importance of considering nutritional responses when selecting scion-rootstock combinations.