Mango grafting is a horticultural technique that physically joins two different parts of plants so they grow as a single tree. This process combines the top portion, known as the scion, from a tree with desirable fruit qualities, with the root system of another plant, called the rootstock. Grafting is necessary because mangoes grown from seed rarely produce fruit identical to the parent tree, known as not growing true-to-type. By grafting, growers ensure the new tree bears the exact, high-quality fruit variety they intend, while also benefiting from a rootstock selected for its hardiness and disease resistance. This method also dramatically speeds up fruiting, allowing a tree to potentially bear fruit in two to four years, rather than the six to ten years required for seed-grown trees.
Preparing the Materials and Timing
Successful mango grafting requires precise timing, usually during the active growing season when the plant’s sap flows vigorously. The period from late winter to early summer, often January through March or May through August, provides the warmer temperatures necessary for the graft union to heal quickly. Grafting should be avoided during periods of extreme heat, heavy rainfall, or when the trees are dormant, as these conditions inhibit the connection between the two parts.
The rootstock anchors the new tree and provides its nutrient and water delivery system. The ideal rootstock is a healthy, vigorous seedling, typically six to twelve months old, with a stem diameter of about 0.5 to 1 centimeter at the cut point. Choosing a rootstock variety known for its adaptability and resistance to local soil diseases ensures the long-term survival and strength of the composite tree.
The scion wood must be collected from a mature, high-yielding parent tree of the desired fruit variety. Scions should be pencil-thick terminal bud wood, meaning they are taken from the end of a branch and contain dormant, swollen buds. The scion should be collected immediately before use, though it can be stored briefly in a cool, moist environment if needed.
Tool preparation requires a sharp grafting knife and pruning shears, as clean, swift cuts are crucial for rapid healing. All cutting surfaces must be sterilized immediately before use, typically with rubbing alcohol, to prevent the transmission of pathogens. Securing materials include specialized grafting tape or clear polythene strips, which will be used to bind the scion and rootstock together.
Step-by-Step Grafting Techniques
The Cleft Graft is a reliable method for mangoes, particularly when the rootstock and scion are relatively close in diameter. This technique begins with preparing the rootstock by cutting it horizontally across the stem, usually about four to six inches above the soil line. Using the sharp, sterilized knife, a vertical cut, or cleft, is then made directly down the center of the remaining rootstock stub, extending approximately one to two inches deep.
Preparing the scion involves creating a precise wedge shape at its base that will fit snugly into the rootstock’s cleft. The scion stick, which should be three to six inches long and contain two or three healthy buds, is given two long, smooth, opposing diagonal cuts. These cuts should meet at a point, forming a sharp, smooth “V” or wedge that is the same length as the cleft in the rootstock. A single, clean slice for each side is preferred, as roughness in the cut can inhibit the union’s healing.
The most critical step is the joining of the two parts, specifically the alignment of the cambium layers, which are the thin, green, actively growing tissues just beneath the bark. The wedge-shaped scion is carefully inserted into the rootstock’s cleft, ensuring the cambium layers of the scion and the rootstock align perfectly on at least one side. This living tissue contact allows the vascular systems of the two plants to fuse, enabling the flow of water and nutrients to the scion.
Once the scion is seated, the union must be immediately and tightly secured to prevent movement and moisture loss. Grafting tape or polythene strips are wrapped firmly around the entire length of the cleft and the inserted scion, starting from the bottom and overlapping upward. The wrapping should exert gentle pressure to hold the cambium layers in close contact without crushing the tissue. All cut surfaces, except the terminal bud, should be covered to seal the wound completely. The final step involves sealing the exposed tip of the scion with grafting wax or placing a small plastic bag over the entire scion to maintain high humidity and protect the fresh cut from drying out.
Post-Graft Care for Survival
Immediately following the grafting process, the newly joined plant requires careful handling. The grafted seedling should be placed in a shaded area, protected from direct, intense sunlight, strong winds, and excessive rain, which can stress the scion or lead to decay. High humidity around the graft site is beneficial for healing, often maintained by the protective plastic bag or tightly wrapped tape.
Monitoring the graft over the next few weeks is necessary. A successful union is indicated by the scion remaining green and plump, followed by the swelling of the terminal bud and the emergence of new leaves, generally within three to eight weeks. If the scion shrivels, turns black, or becomes soft, the graft has failed, usually due to poor cambium contact or excessive drying.
Maintenance involves managing the union and the rootstock’s growth habits. After the scion has produced new, healthy leaves and the union appears secure, the protective wrapping must be removed carefully to prevent the tape from girdling the expanding stem. Any shoots or suckers that sprout from the rootstock below the graft union must be promptly pruned away, as this growth competes for the rootstock’s energy. Maintain soil moisture, but avoid overwatering, as newly grafted plants are susceptible to root rot.