Effect of substrate and cutting diameter on the propagation of Arrabidaea chica (Humb. & Bonpl.) B. Verl. (Bignoniaceae)

Abstract

Arrabidaea chica (H.B.K.) Verlot is a perennial vine which is native to the Amazon region being found mainly in secondary forests or as a cultivated, medicinal plant (treatment of uterine, ovarian, intestinal and colon inflammation, as well as intestinal cramps, bloody dysenteries, conjunctivitis, vaginal infections, leukemia, anemia and diabetes) in household gardens. In the Brazilian States of Amazonas and Pará it is known by the common names crajiru, carajuru, carajiru and pariri among other names. The objective of this study was to evaluate the effect of two different growth media (substrates) and stem cutting diameter on the development of Arrabidaea chica (H.B.K.) Verlot (Bignoniaceae) plants. The experiment was entirely randomized in a 2 X 4 factorial scheme with 5 repetitions (10 stem cuttings per repetition), 2 environments for root development (1 - solid substrate, 2 - water) and 4 basal stem diameters: 1.1, 0.6, 0.3 and 0.2 cm which were classified as woody, partially woody, herbaceous, and apical, respectively. The stem cuttings were ca. 20 cm in length with only apical cuttings presenting leaves. The solid substrate was prepared from sand, argillaceous soil and humus in the proportion 3:1:1. Each cutting was kept in a black polyethylene bag with 1 kg capacity. For the experiments in liquid environment, cuttings of each repetition were placed in clear, polyethylene terephthalate (PET) bottles of capacity 2 L (with tops cut off), containing approximately 500 mL of water, which was renewed every three days to avoid the proliferation of insect larvae. From the start of the experiment in July, 2003 stem cuttings/developing plants were maintained in areas having clear plastic protective roofing and were irrigated daily. After 90 days, the following variables were evaluated: established plants (%), average aerial (shoot) and root growth (both in cm), and average dried leaf and root masses (both in g plant-1). Averages were analyzed at 5% probability. There was no significant interaction only in the average root growth per plant. In the solid substrate (1), the percentage of established plants was superior in stem cuttings of basal diameter 0.6 cm and for other variables development in general was better in the solid substrate. The greatest development was observed for stem cuttings of basal diameter 1.1 cm, in the solid substrate.