ROOTING SOFT CUTTINGS OF SOURSOP (ANNONA MURICATA) 'GIANT OF ALAGOAS'

Soursop (Annona muricata) is a tropical fruit tree that occupies a promising position in today’s Brazilian fruit market. The growing demand and interest by the processing industries of sorbets and juices for the soursop pulp justifies the increasing production areas in northeast Brazil. Nevertheless, most of soursop plants have been propagated by seeds which bring as a consequence highly heterogeneous orchards. Therefore, vegetative propagation of elite trees has been recommended to produce uniform and more productive orchards. Among the existing cloning methods, stem cuttings is one that presents simplicity, speed, low cost and has been preferred by commercial nurseries. The objective of this work was to improve the vegetative propagation of soursop by cuttings and to study the effect of length, number of leaves and leaf area on the rooting process of soursop soft minicuttings. Thus, the feasibility of propagating the soursop by means of soft stem cuttings has been investigated on an entirely randomized 2×3 factorial experiment with four replicates and 10 cuttings per plot. The soft cuttings were collected from apical branches of eight-year-old trees with 12 cm and maintained with 2 or 4 leaves left entire, halved or with a quarter of their original length. All cuttings had the base treated with 2000 mg/kg acid indole-3-butyric acid (IBA) powder. After 6 weeks the percentage of rooted cuttings, number and length of roots, and number of remaining leaves on cuttings were examined. Soft stem minicuttings revealed high capability to root. The percentage of rooted soft cuttings was about 70% on two leaves cuttings. The length of the minicuttings did not influence rooting ability. The lower number and size of the leaves significantly improved rooting percentage and number of roots. Rooting percentage was about 70% on soft cuttings with a pair of trimmed leaves.