Grafts can be used for planting. For grafting, raise seedlings in polythene bags and when they are 9-12 months old do inarching. One month after grafting, behead the root-stock above the graft joint.
Epicotyl grafting can be undertaken successfully in jack. 3-4 month old, 10cm long scions are grafted on 5 day old rootstocks in polythene bags by the cleft method during the month of June and kept under moist conditions. The scions should be pre-cured 10 days before grafting by clipping the leaf blades and keeping the petioles intact on the twig. The graft union is complete by 80 days after grafting operations.
A new method of approach grafting utilizing sprouted jack seedlings (maximum 20 days old) as root stock and tender shoot tips of 2 to 3 weeks old with one or two tender leaves as scion is successful, fast and cost effective.
Planting
It can be planted at the onset of monsoon showers. Seedlings or grafts are planted in pits of 60x60x60cm size at a spacing of 12-15 m. Refill pits with mixture of topsoil and 10kg compost or FYM per pit to a level higher than the adjoining ground. Plant the grafts in the same depth as they were in the containers, preferably in the late evening. Deep planting results in poor growth of the graft. Ensure that the graft joint is above the soil level. Stake the grafted plants to prevent snapping at the graft joints.
Excellent drainage and adequate watering need to be ensured. At no stage it should be exposed to drought and frost. It is useful to provide some protection, especially to young trees. Jack is rarely manured. Even without fertilizer application, the jack trees come up well under Kerala conditions.