There are several reasons why it might be necessary to use transplanted seedlings for the establishment of agroforest plots. The most obvious one is that it avoids the planning and serendipity of obtaining seed from trees whose fruiting time can be hard to predict and whose seeds cannot be stored, or where parrots and monkeys find the fruit first. Often if appropriate Inga species can be found nearby then the chances are there will be a bank of seedlings also. Fortunately there are few predators of the seeds so even when the fruit have been eaten, the seeds will normally make it to the forest floor where many will germinate.
Transplanting is stressful for seedlings as the process of digging up and re-planting can profoundly impact the roots. We do not know what the upper limit for transplanting seedlings is, or how many will survive and if they do how long they will take to reach the size required for planting. To get answers to some of these questions we transplanted 400 naturally regenerating seedlings of undomesticated Inga edulis and I. ingoides. Preliminary results suggest that although transplanted seedlings develop more slowly than sown seed, over 3/4 survived the transplantation process. In the case of transplanted Inga edulis, four months after planting the transplanted seedlings were 20-25 cm tall, about half the height of sown seed of domesticated varieties. This is towards the lower limit of what would be suitable for planting out. Whilst we don’t know what the rate of sown-seed would have been, we do at least we know that transplanting is a viable source of seedlings. The lower growth rate may even be an advantage as it means that seedlings can be kept for longer periods prior to planting and so add flexibility to our planting schedule.