Handbook of Vanilla Science and Technology

Hand pollination is a daily task for a period of 3 months. Per hectare, 300 to 600 days of work are required to carry out pollination, depending on the abundance of flowers, their location, efficacy of the pollinator, and distance between plants.

1.12.4 Quantity of flowers to be pollinated

In general, 6 to 8 flowers per raceme are pollinated to ensure obtaining a minimum of 4 to 5 fruits of acceptable quality (pollination is not 100% successful). Obtaining 100 to 120 fruits per plant requires 8 to 5 flowers per raceme to be pollinated. These approximations are rough since much depends on environmental conditions, the position and vigor of the plants, as well as the biological characteristics of the clone or cultivar. Vanilla growers determine the amount of flowers to be pollinated by considering pricing as well. Over-pollination leads to an abundance of many smaller fruits of lesser value that increase the cost of pollination and exert a heavy cost on the plants. Over-pollination is also associated with major fluctuations in production volume from year to year (Hernández 1997).

1.12.5 Fruit development

Immediately following hand pollination, pollen tubes begin their germination and growth and eventual fertilization of the ovules. The ovary quickly begins to enlarge and assume a strong, dark green aspect as it orientates itself downward. The maximum length and diameter of the fruit is achieved 45 days after hand pollination (Figure 1.5). Afterwards, growth ceases, and the fruit enters into a period of maturation lasting roughly 7 to 8 months.

Fig. 1.5 Developing vanilla fruits.

1.13 HARVESTING

The harvest in Mexico begins on December 10 of each year, in respect of an agreement taken by growers, curers, and industrial manufacturers. Growers harvest their entire crop in a single day, with the fruits at different stages of development. These stages can be significantly different, since flowering occurs over at least a 3-month time period. The heterogeneity in harvested fruits effects attempts at dehydrating the beans during the curing process, since immature fruits lose water more quickly than mature fruits.

The ideal is for fruits to be harvested only when they have reached a ready stage for commercialization, that is, when the distal tip of the bean changes color from green to yellow. This transition normally occurs 8 to 9 months following pollination.

1.13.1 Harvesting practices

In order to avoid rapid dehydration, the whole bundle or raceme of fruits is harvested with hand shears. The central stalk of the inflorescence, the rachis, remains attached. Harvested fruits are placed in baskets or plastic crates to prevent mechanical damage, which can lead to pathogen infection. The fruits are also kept in well ventilated and shady areas.

After harvesting, it is customary to prune shoots that have already flowered. These shoots will not produce again (or as much) unless they retain buds. The pruning is performed with a knife or blade that is disinfected prior to use in a solution of 1 part bleach to 6 parts water.

The removal of “spent” shoots serves to eliminate unproductive parts of the plant that occupy space and deplete the plant's energy resources. Their removal facilitates the maintenance of adequate ventilation and light conditions for the plant. Some of these spent shoots may serve as cuttings to start new plants if they retain meristematic tissue.

1.13.2 Preventing theft

Mexico has taken some actions to prevent theft:

I Each grower should have a permit to transport and sell vanilla. The permits can be obtained direct from SAGARPA, from the Consejo Nacional de Productores de Vainilla, from regional government offices, or from local officials. Officials may confiscate vanilla from a person who cannot present their permit. Middle-men are notified that they should not buy vanilla from a grower who does not present his/her permit, since the vanilla could have been stolen. In practice, middle-men do make purchases without permits, since they can obtain more vanilla for a cheaper price.

II Growers have sought out and receive help from state security forces to protect and transport vanilla (via horse-back escorts or helicopters). This happens when the price of vanilla is high, so when the risk of theft is high.

1.14 GREEN VANILLA COMMERCIALIZATION

The majority of vanilla growers in Mexico sell non-value-added, green vanilla to middle-men and processors who cure and export the cured vanilla beans. The two cities of Papantla and Gutierrez Zamora, both in Veracruz, serve as the centers of vanilla curing and export. Green beans are sourced from growers in the state of Veracruz, as well as from Puebla and Oaxaca.

1.14.1 Prices