Substrates and fertilization for the rustic cultivation of in vitro propagated native orchids in Soconusco, Chiapas

Abstract

AbstractNative orchid cultivation is a compatible alternative for impoverished coffee farmers in southeastern Mexico who are in crisis due to falling prices. Sustainable orchid cultivation is also an urgent necessity as an alternative to nonsustainable extraction from protected reserves, forest fragments and traditional coffee plantations, and to restore and conserve populations within these habitats. Our objective was to test the effects of locally available substrates and fertilizers upon orchids cultivated under typical rural conditions in coffee-producing areas in Soconusco, Chiapas. Seven species of epiphytic orchids native to Soconusco region—Cattleya aurantiaca, Brassavola nodosa, Prosthechea (Encyclia) chacaoensis, Anathallis (Pleurothallis) racemiflora, Cattleya skinneri, Cycnoches ventricosumandEncyclia cordigera—were propagatedin vitro, acclimatized and established in rustic orchid galleries in the home gardens and plantations of coffee growers. Locally available waste products were used as substrates: clay tiles, tree bark, bamboo, seed hulls of pataxte (Theobroma bicolor) and wire baskets filled with bark chips. Two cheap and readily available commercial foliar feeds, Algaenzims (an organic product) and Bayfolan (a synthetic product) were tested. First, the substrates alone were tested for a period of 6 months to 1 year, then a combination of substrates and fertilizers were tested for 6 months, for effects upon leaf and root growth and root number. The mortality rates of these nonsymbiotically propagated, epiphytic orchids during the acclimatization phase, prior to these experiments, were high, between 60 and 90%. Once established in rustic galleries, the young orchid plants showed no preference for a particular substrate, survival depended upon technical problems during establishment, relating to difficulties with the attachment of plants to substrates, and the variable quality of care and attention offered by the farmers. Both fertilizers significantly improved one or all the parameters studied, and possibly counteracted the negative effects of the absence of symbiotic fungi, which, under natural conditions, are essential for orchid seed germination and adequate development of the young plant. More than half of the producers did not continue with the orchid cultures for economic and cultural reasons.