Comprimento de mini-estaca e ácido indol-butírico na propagação de tangerineiras

Abstract

In Brazil, the citrus sector is one of the most promising economically, especially in the production of oranges and mandarins. However, the production of rootstocks still presents problems due to the fact of using seeds, which could be solved by adopting the asexual propagation method, such as minicutting. However, this method presents low rhizogenesis, and it is necessary to test some technique that allows its multiplication more easily. Thus, the objective of this work was to evaluate the propagation by minicutting of mandarins Ponkan (Citrus reticulata Blanco) and Montenegrina (Citrus deliciosa tenore), with different lengths of minicuttings and doses of Indol-Butyric Acid (IBA). The work was carried out at the Universidade Tecnológica Federal do Paraná - Campus Dois Vizinhos. The experimental design was completely randomized (DIC), in a 2 x 2 x 3 factorial (citrus x length of the minicuttings x IBA concentration), with four replications, using 20 minicups per experimental unit. The parent plants (propagation material) used were adult semi-woody branches of Ponkan and Montenegrin tangerines. The length factor of the minicuttings involved two levels, 4 and 6 cm and the concentration of IBA, three levels, O, 1000 and 2000 mg L-1. At 120 days after the beginning of the experiment, the percentage of rooting, calogenesis and survival, as well as the number and length of the three largest radicels were analyzed. There was a significant effect for the length factor of the minicuttings, where the 4 cm lengths showed greater rooting (3.46%), number of primary shoots (1.03), number of new leaves (2.14) and survival (32.34%). Although it is possible to obtain rhizogenesis and survival of minicuttings in the length of 4 cm, the values obtained are considered low and new studies must be performed, adapting the methodology used.