Evaluation of rooting and growth of pitaya (Hylocereus spp.) cuttings in soilless production: comparison of hydroponic vs. aquaponic systems

Effluents generated in aquaculture could contribute to increased risk of environmental contamination. Aquaponic could facilitate the resolution of this problem by transforming those potential pollutants into nutrients for plants, providing an extra vegetable production in a circular economy framework. Highly profitable vegetables such as pitaya (Hylocereus spp.) could improve the economic viability of these farms, but little is known about its performance in aquaponic systems. Rooting and vegetative growth of 12 cuttings of white-fleshed pitaya (Hylocereus undatus) and red-fleshed pitaya (Hylocereus hybridum) were evaluated over a period of six months in two aquaponic systems rearing tilapia with different hydroponic subsystems (Nutrient Film Technique, NFT and Media Bed, MB). A control group of hydroponic culture using substrate filled pots was used for comparison. Water quality and environmental parameters were also measured to evaluate their influence on plant development. Hylocereus hybridum showed higher vegetative growth, and earlier shoot emission in combination with the control system, followed by the NFT and finally the MB. In relation to root growth, Hylocereus undatus showed best results in combination with the substrate system. Best results for precocity in root emission, evaluated in the NFT system, were obtained for Hylocereus hybridum. Water quality parameters had no significant effect on plant development, while fish live weight increased in both systems.