Shading of stock plants and the use of auxin in red pitaya cuttings

Abstract

Although there has been a significant expansion of red pitaya cultivation in Brazil and other countries around the world, its cultivation requires scientific expertise to identify the plant production systems best suited to Brazilian soils and climate. Therefore, this study aimed to evaluate the effect of exogenous auxin and shading of the parental stock plants on the subsequent quality of red pitaya cuttings. The use of a commercial rooting auxin (with and without) and five shading levels on stock plants (full sun, 35, 50, 65 and 80% shading) were tested via four randomized blocks in a factorial 2x5 scheme with two plants per plot. After 90 days, the following vegetative characteristics were evaluated: length of the longest root (LR), root dry mass (RDM), root width (RW), shoot fresh weight (SFW) and shoot dry weight (SDW), total dry weight (TDW), number of axillary shoots (NAS), sum of the length of the axillary shoots (SLAS), and shoot:root ratio (SRR). We concluded that for the production of high quality plants, collecting cuttings from stock plants grown in full sun or 80% shade is recommended, eliminating the need to use commercial rooting auxin.