Araucaria angustifolia grafting: techniques, environments and origin of propagation material

Araucaria angustifolia (araucaria) is a remarkable species in the Mixed Ombrophilous Forest. The low germination of the stored seeds and its long reproductive cycle make grafting a good alternative for propagation, making possible to obtain genetically superior trees with early fruiting. However, araucaria grafting is still fraught with technical problems, culminating in low graft survival. With the objective to define and be able to explain the best methodology for the grafting of araucaria, we conducted studies based on five experiments evaluating the effects of: (I) environment and sex on graft survival; (II) methods of grafting and budding with shoots from stumps of stock plants; (III) techniques, indoor (nursery) and outdoor (directly in the field) grafting; (IV) budding with buds from different origins; and (V) chip budding with shoots from pruned apices of two ages stock plants. Graft survival was assessed throughout the experiments and the graft-union at the end. The use of controlled environments for grafting was favorable, especially in the glasshouse (64.1 % survival). Scions from female plants (55.5 % survival) showed higher suitability for grafting. Chip budding with shoots from pruned apices of 25 and 35-year-old stock plants showed survival of 87.5 % and 85.0 %, respectively. It is a technology that has unlimited potential for araucaria grafting, which may significantly contribute to its sustainable use.