Handbook of Vanilla Science and Technology

This system is normally practiced in deforested areas that have been used to cultivate another crop. The name of this system is “pure cultivation” (Chauds 1970), and the first step consists of planting support trees. After a year, when there is sufficient shade (50%), the vanilla is planted (Pennigton et al. 1954). This system is utilized by growers with more economic means, in lots of 0.5 to 2 ha per grower.

Support trees that are regularly used are “pichoco” (Erythrina sp.) and/or “cocuite” (Gliricidia sepium), two leguminous trees with the capacity to fix atmospheric nitrogen and that can be propagated clonally through cuttings. Per ha, 1,000 to 5,000 support trees are planted, as are 2,000 to 10,000 cuttings of vanilla (2 vanilla plants/support tree). The planting distances between trees are 1 × 2 m, 2 × 2 m, 1.5 × 2.5 m, and 3 × 3 m.

This system of vanilla cultivation has the advantage of relatively high yields, but generally only in the fourth or fifth year after planting (second or third harvest). After this time, yields decline drastically, most likely due to the difficulties of managing mature plants in such a confined space (especially for adequate shade and ventilation).

Yields of green vanilla beans vary from 1 to 2 tons per ha in rain-fed systems, and 2 to 4 tons per ha with a higher density of plantings (10,000 plants per ha) and with irrigation.

Establishing a monoculture of vanilla from a cleared area requires around $10,000 USD to cover the costs of establishing support trees and the high density of plantings. Maintenance costs per year average $7,500 USD.

1.2.3 Vanilla cultivation in existing orange groves

Orange trees are excellent support trees for vanilla, because their branches are durable and grow laterally and are able to support a good quantity and distribution of shoots (Figure 1.1). These features help mitigate the problem of the shoots shading out other shoots. The canopy of orange trees is capable of providing vanilla plants with sufficient sunlight throughout the year. In most systems with orange trees as supports, vanilla flowers in the second year.

Fig. 1.1 Vanilla vines growing on orange trees as a support.

This system is one of the best ventilated, with a low incidence of pests and diseases. Yields are higher and costs of production are lower because orange trees in coastal Veracruz have been extensively cultivated for decades.

Many of the vanilla growers started off cultivating oranges and continue to do so when managing vanilla. The vanilla plants are established when the orange grove is producing. Orange trees that are selected as supports have an average height of 4 m and a well-formed canopy. Dry branches (“chupones”) are pruned, as are those in the interior of the canopy that impede the spread of vanilla plants as they are growing or block out too much sunlight.

Densities of orange tree plantings vary between 204 to 625 individuals per ha. Trees are spaced on a grid of 4 × 4 m, 5 × 5 m, 6 × 6 m, and 7 × 7 m, and 3 to 6 cuttings of vanilla are planted per orange tree, yielding a total of between 1,224 and 1,875 vanilla plants per ha.

Growers manage 1 to 5 ha and harvest 500 to 2,500 kg of green vanilla/ha, although most obtain 1 ton.

Establishing vanilla cultivation in an existing orange grove requires a minimum initial investment of $7,000 USD/ha. The orange trees represent an economically sustainable resource in the sense that they do not have to be purchased or planted. Annual maintenance costs average $6,000 USD/ha per year.

1.2.4 Shade houses

This is the most recent and intensive form of vanilla management in Mexico. Its principal feature consists of substituting or complementing natural shade with artificial shade by means of shade cloth (black or red) of 50% luminosity, which is stretched above all the support trees at ca. 3 to 5 m high, at the four sides of the planted area. These systems are referred to as “shade houses”. In size, they are usually on the order of 25 × 40 m (1,000 m²) and some are up to 1 ha.

Shade houses most commonly feature artificial or “inert” support tress, such as concrete posts, or posts made from wood or bamboo. On occasion, living support trees, such as “pichoco” (Erythrina sp.) or “cocuite” (Gliricidia sepium), are used in lieu of or in combination with artificial supports. High planting densities are typical of this system, with 254 to 2,500 supports and 1,524 to 2,500 vanilla plants per 1,000 m².

Shade houses are appropriate on flat ground that has been deforested or on patios, and for use by growers with relatively more economic means. The initial investment is high, usually $10,000 USD per 1,000 m², with annual maintenance costs of $2,000 USD. For this reason, most shade houses in Mexico are subsidized by the government.