A Cost-Effective, Simple, and Productive Method of Hydroponic Culture of Edible Opuntia “Maya”

Abstract

The stem of the cactus Opuntia (genus Opuntia, subfamily Opuntioideae, family Cactaceae), commonly referred to as the nopal cactus or prickly pear, is widely consumed as a vegetable in Mexico and in the Mediterranean countries (Stintzing and Carle, 2005; CruzHernández and Paredes-López, 2010) as well as in Japan, where it is produced mainly in the Kasugai City, Aichi Prefecture. These plants are also used in some countries as a remedy for a variety of health problems including edema and indigestion (El-Mostafa et al., 2014). Opuntia plants are commonly produced through soil or pot culture; however, the cultivation of vegetables using soil exposes them to soil-borne diseases and salt accumulation and also poses the difficulties of fertilizer management (Lakkireddy et al., 2012). In a hydroponic culture, plants are grown using a nutrient solution (water and fertilizer), with or without the use of an artificial medium. The absence of soil results in an absence of weeds or soil-borne diseases, while precise fertilizer management is readily achieved (Lakkireddy et al., 2012). Thus, there are many advantages associated with the hydroponic culture of edible Opuntia, although this method is not yet commercially practiced. With respect to the growth behavior of Opuntia, flat paddle-shaped daughter cladodes develop from the areole of the mother cladode, and this process is repeated (Pimienta-Barrios et al., 2005). We have previously shown that edible Opuntia can be grown by hydroponic culture using the commercially available bubble wrap and a cultivation panel (Horibe and Yamada, 2016a; Horibe et al., 2016b). However, it was difficult to attach cladodes using these items due to their characteristic stem shape, and cladodes occasionally fell into the culture solution as the fixative loosened. For the hydroponic culture of most vegetables, seeds are spread on the commercially available cultivation panel; however, in the case of edible Opuntia, vegetative propagation using the stem is commonly used for its production because this method is much faster and easier compared with seed propagation. Thus, an appropriate method for the hydroponic culture of edible Opuntia should be developed. In the present study, we designed a new method for the hydroponic culture of edible Opuntia using a deep flow technique (DFT), and investigated the effectiveness of this method by comparing the cladode growth using this method and with pot culture using a growth chamber and a greenhouse. In this novel method, we used cheap materials while we did not use aeration, which requires a power source, thereby facilitating the cost-effective cultivation of Opuntia anywhere.