Porta-enxertos e enxertia de castanheira-do-brasil pelo método da borbulhia em placa.

Abstract

A large part of Brazil nut production comes from extraction in native areas. Thus, thesuccessful exploitationincultivationsystems is highly dependent onvegetative propagationtechniques, to maintain the genetic traits and shorten the juvenile period of selected genotypes. Thisstudy aimed to determine the optimal age of Brazil nut rootstocks to performgrafting by patchbudding method, as well as to verify the percentage of graft survival and the initial growth ofdifferent clones in Roraima. For this purpose, two experiments were installed in a randomized blockdesign, with four replications. The treatments were arranged in a split-time scheme in time, such asthe genotypes considered the plots and the evaluation times the subplots. It were evaluated rootstockgrowth traits, percentage of alive grafts and sprouts growth traits. The rootstocks reached therecommended size for grafting between 26 and 34 months after planting, indicating slower growthwhen compared to other locations. At 1 20 days after grafting, it were obtained percentages of graftsurvival ranging from25%to 1 00%, depending on the graft genotype. The overall averagepercentage of survival was over 70%. The initial growth (height, diameter and number of lateralshoots) of shoots observed for some genotypes is indicative of their adaptation to the cultivationconditions considered. As the Brazil nut tree is a perennial species, both the growth in older ages, aswell as the future productivity and longevity ofthe plants must be monitored.