Efeito das soluções enraizadoras AIB, 2,4-D e ANA em estacas de guaranazeiro

Abstract

Propagation of guarana by cutting is a technique that allows the fixation of the selected genotypes, producing seedlings of higher productivity and/ or resistance to diseases. There are no studies with guarana cuttings treated with 2,4-D and NAA, however, treatment with IBA for rooting is the method currently used for the different clones. This work was carried out with the objective of evaluating the rooting of sixteen guarana genotypes submittto the use of different rooting solutions. The experiment was carried out by Embrapa Western Amazon from June to September 2019, in the nursery of the Experimental Field of Embrapa, in a randomized block design, with a factorial arrangement of 16 genotypes x three growth regulators (IBA, 2,4-D and NAA) + 16 additional controls, with 2 replicates and 10 plants per plot. After 90 days, the percentage of rooted cuttings (%), cuttings with calluses (%) and dead cuttings (%), the number of roots, length of the longest root (cm), root volume (mL), fresh weight of roots (g) and root dry mass (g). Among the regulators tested, the addition of IBA and NAA provided improvements in the quality of the root system in guarana genotypes. Average mortality was influenced by treatment with 2,4-D, showing greater toxicity to cuttings. Except the percentage of cuttings with calluses, all other characteristics were influenced by the different growth regulators. The genotypes showed different capacities, regarding the rooting of their cuttings, indicating the CMU 1004, CMU 1005, CMU 1006 and CMU 1014 with higher percentages of rooted cuttings, while CMU 1016 and CMU 1022 are the least indicated for propagation by cutting. Although there was significant interaction between genotypes and growth regulators for root volume, fresh and dry weight , there was no significant contrast between this factorial versus control (untreated genotypes). Thus, the use of regulators, under the conditions of this experiment, does not influence the rooting of guarana cuttings.