Pollination is a miracle of nature. During the summer season, life spreads because of varied forms of pollination: insects, the wind, animals and even water.
But what happens in the Jardin botanique’s tropical food plants greenhouse when summer’s over, when shutters stop opening, when nature is at rest? It’s at that moment that a new pollinator springs into action: specialized horticulturist Catherine Boudreault takes her turn at being a “bee”!
What does hand pollination mean?
First of all, pollination is the act of sexual reproduction in a large proportion of plants, consisting of the transport of pollen from male organs to female organs. It ensures fertilization and the production of seeds and fruit. This pollination can also be carried out manually by humans.
In that case, the horticulturist consults her flowering calendar. Although the dates vary from year to year, the seasons when flowers appear are similar for each species. Next, Catherine makes sure she clearly distinguishes the sexed parts of a flower. Flowers vary in shape and structure in ways that can sometimes be surprising! Finally, the horticulturist has to recognize the moment of receptivity of the sex organs, meaning the moment when the pistil (female part) is disposed to welcome pollen (male part). If it happens to be the wrong time, fertilization will fail.
How is hand pollination done?
Hand pollination of flowers has to be done in a tight timeframe. Flowers open successively throughout the day, and generally speaking are receptive only for a brief moment. It’s therefore advisable to take care of things in the morning, before noon, or a little later in the afternoon.
Soft natural-fiber brushes that have been cleaned and disinfected are used to collect pollen and deposit it on perfectly formed flowers. The freshest pollen will yield the best results.
Does hand pollination take place all winter?
Fortunately not! Banana trees are parthenocarpic, meaning they produce fruit without the need for an act of fertilization. This year there have been more than 20 bunches of bananas! The jackfruit, meanwhile, has male and female flowers at the same time. Pollen from the male flowers, once released, falls naturally on the female flowers located nearby. The jackfruit in the tropical food plant greenhouse this year produced a fruit weighting 48 pounds! This incidentally is the tree that produces the largest fruit in the world, capable of reaching close to 100 pounds.
The particularities of manually pollinating vanilla
This graceful climbing orchid, a native of Central America, is cultivated in many countries having a tropical climate. In its natural environment, vanilla is pollinated by the Melipona bee, but in Québec that bee doesn’t exist. How does the horticulturist manage to obtain vanilla pods in the exhibition greenhouse? The pollinia, the club-shaped structures in which pollen grains are massed, have to be collected by hand and deposited on the pistil. That technique, known as the “Marriage of Vanilla,” was perfected in 1841 by the renowned Edmond Albius, a plantation slave on the island of Reunion.
Despite the many efforts we make to synchronize hand pollinations, it inevitably happens that some appointments get missed. But not to worry: the determination of our specialized horticulturist to present you with the greatest possible number of fruits throughout the year is boundless!