Phytoregulators and stem subdivision in the production of young forage palms (Opuntia ficus-indica and Nopalea cochellinifera)

The propagation of plants through stem subdivision and the incorporation of phytoregulators can be a viable and efficient technique in the large-scale production of young forage palm at a lower cost. This study was conducted in order to evaluate the influence of stem subdivision and phytoregulators on the production of young forage palms under greenhouse conditions. Three experiments (I, II and III) were performed. Experiments I and II consisted of young palm of the Miúda genotype, formed from fragmented stems submitted to solutions containing gradually increasing concentrations of benzylaminopurine (0,0; 0,5; 1,0 e 1,5 mg. L-1) and kinetin (0,0; 0,25; 0,5 e 0,75 mg. L-1) combined with naphthaleneacetic acid (1,5 mg. L-1). An additional control without the use of phytoregulators was also included. These treatments were distributed in a randomized block design (RBD), in a factorial scheme with the additional plot: 4 x 4 + 1. In experiment III, different sized fractions of four forage palm genotypes were tested: Gigante, Orelha de elefante, IPA Sertânia, and Miúda. For this test, the experimental design was RBD, with twelve treatments, distributed in five blocks with five plants per plot. There was no influence of phytoregulators on the characteristics evaluated in experiments I and II. Significant differences were found. However, for the variables length, width, and thickness of sprouts among treatments in experiment III. Therefore, the application of phytoregulators in young forage palms at the dosages used is not recommended. For the Gigante, Orelha de Elefante and Miúda genotypes, the fractional stem size recommended is 5x3 cm whereas for IPA Sertânia, the size recommended is 4x2 cm.