Effect of Manuring with Commercial Products and with Local Resources on the Output of Organic Dragonfruit (Hylocereus undatus)

The dragonfruit [Hylocereus undatus (Haworth) Briton & Rose] is a crop of growing economic relevance in the Mexican Yucatan Peninsula due increasing demand on the international market for this climbing cactus, its relatively high pest and disease tolerance, the fruit’s low nutrient and water demand along with dragonfruit’s general adaptation to the subhumid climate and to the (flat and calcareous) soils of this region. Even the only challenging management aspect of this plant, its dependence on trellises, is feasible in this region since selected trees of the local forest can be used for this purpose. Despite this considerable applicability for sustainable farming, organic dragonfruits from Yucatan are still rare. In a series of trials implemented (2010–2013), a dragonfruit organic crop management was established in Chun Yah, central Yucatan. The goal was to create a production system highly independent from external inputs, due to the poorly developed infrastructure of this region. Regarding the manuring of the crop, a management based on a commercial organic foliar treatment was compared, first, to the soil amendment of decomposed cow manure and wood ash and, second, to a control group without fertilization. Weed management was selective. Pests and diseases were controlled using extracts from native species. Bursera simaruba and other endemic trees served for staking. There was no irrigation. The dragonfruits were established in 2010; harvesting (three to four times a year) started in 2011. The arrangement was a randomized block system adapted to the local ecosystem. Yearly harvest results showed that the control variant (4.8 t/ha) was on a par with the local conventional production. Bromatological data suggests that an unsatisfied demand for K was the only seriously limiting fertility factor prevailing in the local ecosystems. However, both organic treatments recorded in a significantly higher annual yield of 6.4 t/ha. Yet, annual management and investment costs of U.S. $1,970 per hectare (at a yearly output of U.S. $3,340 per hectare) are 154% higher when using commercial products than when applying cow manure and ash. Consequently, sustainable production of the dragonfruit, embedding the plant to the local forests and using organic management, results in competitive yields compared to the production based on synthetic products. Furthermore, this strategy is cheaper for local producers, provided cow manure as well as ash are used for manuring instead of commercial organic nutrition products.