Establishment of a Sustainable Production System for Chaya (Cnidoscolus aconitifolius) in Quintana Roo, Mexico

Spinach tree, or chaya (Cnidoscolus aconitifolius Mill.), is an autochthonous mesoamerican euphorbiaceous. Wild types of chaya are characteristic species of the rainforests of the Yucatan Peninsula. A domesticated subvariety of chaya is frequently observed in local home gardens, as the boiled leaves of this plant are an essential component of traditional Mayan cuisine and medicine. The leafy perennial shrub is an excellent source of vitamins and minerals; it is also rich in antioxidants. Yet, it is the high protein content of chaya that sustains the seminal potential of this plant as food, forage, and medicinal crop. However, there is no intensive production of the spinach tree so far, which is why an entire production system has to be developed. In José María Morelos (central Yucatan), several field trials have been dedicated to the establishment of a sustainable crop management for chaya. Since 2014, as the first and essential parameter, the optimum arrangement for cropping the spinach tree has been determined.  Three variants were compared: 1) Monocropping of chaya with a density of 50,000 plants/ha; 2) monocropping with 25,000 plants/ha; and 3) intercropping the spinach tree with roselle (Hibiscus sabdariffa) for its similar nutrient and water demand. In the latter variant, both plants were established at a density of 25,000 plants/ha. The trial was arranged in a randomized block system. The management was organic with emphasis on using local resources. There was no irrigation. Clones of the so-called sweet chaya, the most common phenotype in local gardens, were established in rows 2 m equidistant (with varying planting distances in between the rows). The effect of this arrangement on the development of chaya was evaluated by the vegetative growth of the recently established cuttings. Height increment was identical in all three variants. Foliar size and number, as well as stem growth, were inferior in the intercropped variant, but they were at the same level in the case of monocropping. In the denser variants, a tendency of slower vegetative growth in the dryer months is monitored. So far, no substantially harmful pests and diseases have been observed. Although agrobiodiversity is consequently useful for sustainable production, first results show that intercropping the chaya with roselle is not a recommendable strategy for obtaining this diversity.