Grafting of thornless 'faveleira' Cnidoscolus phyllacanthus

摘要

> size="2" face="Verdana, Arial, Helvetica, sans-serif">The faveleira tree (Cnidoscolus phyllacanthus Pax et K. Hoffm.) is a forage producing xerophyte of the semiarid region of Northeast Brazil. Forage collection from faveleira plants is difficult due to its caustic thorns, however thornless mutants may be reproduced vegetatively. The present study was carried out in the Seedling Nursery of UFCG, in Patos-PB, to develop a protocol to produce thornless faveleira seedlings by full cleft-grafting using grafts in the dormant or active growth phase on rootstocks in the active growth phase. Dormant grafts were kept refrigerated (+5°C) (T1) or protected from the sun at room temperature (T2), for three days before grafting in December 2003, while active growth grafts were cut off from the tree in December 2003 (T3) or June 2004 (T4), just before grafting. There were 38, 26, 40 and 30 grafts for T1, T2, T3 and T4, respectively. Data collected in successful grafts consisted of rootstock and graft diameter and height, and percentage of successfully sprouted grafts. Rootstock and graft mean diameter (from 10.9 to 11.9mm and from 8.6 to 9.6mm, respectively) and height (from 7.7 to 12.6cm and from 23.7 to 29.8cm, respectively) were similar for all treatments. Grafting was successful in 45, 85, 15 and 33% of the cases for T1, T2, T3 and T4, respectively. Thus, the use of dormant 9mm-thick and 25cm-high grafts, kept protected from the sun at room temperature for three days before grafting, results in the highest rate of success in grafting of thornless faveleira.