Vegetative propagation of Manilkara bidentata (A.DC.) A.Chev. using mini-tunnels in the Peruvian Amazon region

Aim of the study: Manilkara bidentata (A.DC.) A.Chev. (‘quinilla’) is a Neotropical tree highly threatened by extensive agricultural practices and climate change, resulting in a substantial reduction of natural stands and seed availability. Commercially, the propagation through seeds of this species is severely impeded by a low germination rate. Vegetative propagation could be an alternative tool for overcoming this limitation. This study aims to evaluate the vegetative propagation of M. bidentata by rooted cuttings using mini-tunnels in the Amazon.Study area: National University of San Martín, Tarapoto, Region of San Martín, Peru. Forested areas at three localities in the Picota province and two localities in the Bellavista province, San Martín Region, were visited for the selection of plus trees and collection of epicormic shoots from stumps.Materials and methods: the study was performed on leaf areas of 0, 50, and 100% with indole-3-butyric acid (IBA) treatments of 0, 3000, and 6000 ppm, for 9 treatments combinations. The experiment consisted of 3 mini-tunnels, with 3 growth trays established on each mini-tunnel, and 16 cuttings established on each tray (and per treatment), for a total of 144 cuttings.Main results: after 55 days, the best scores in rooting rates (75%), number of roots (3.88), root length (3.26 cm), and budding percentage (94%) were obtained for the combination of 50% leaf area left with 3000 ppm of IBA.Research highlights: we propose the technique of mini-tunnel as a tool for the cloning, rescue, and germplam conservation of M. bidentata.Key words: mini-tunnel; Peruvian Amazon; quinilla; rooting; vegetative propagation.Abbreviations used: indole-3-butyric acid (IBA).