Table of contents:
- What is pollination?
- Who helps the plants?
- Boundary conditions and force majeure
- How can we help plants to pollinate?
Video: Little Workers Of Big Harvest - About The Role Of Pollinators In Plant Life. Photo
Cherry blossoms - as if doused, and the cat cried fruit. Many are familiar with this situation. Not only with cherries, with many fruits, this happens periodically. Or a vegetable marrow, for example: it has blossomed, and the ovaries begin to rot. It would seem - where is the cherry, and where is the marrow? It turns out that the reason is common - insufficient pollination. Although plants have been “settling” this issue themselves for millions of years, there are still failures. This article is about this important process, its participants, and how to help the “outsiders”.
- What is pollination?
- Who helps the plants?
- Boundary conditions and force majeure
- How can we help plants to pollinate?
What is pollination?
At first, the plants did not rely on anyone in the important fertilization process. One has only to look at the conservative ferns in this matter to feel the whole complexity of the procedure. Gymnosperms are somewhat more advanced, but this event also takes quite a long time for them.
The angiosperms decided to live in a new way and got themselves stamens-pistils. The process went more fun. At first, as usual, chaotic, and then more and more specialized. An example of extremes in this matter is the pollination of figs by blastophagous wasps inside the fruit. And figs can no longer reproduce without wasps, and wasps without figs too.
There are two types of pollination: self-pollination, when all the hope is on oneself, and cross-pollination, which requires an intermediary. Self-pollination is more reliable, and cross-pollination is more progressive, since it gives a huge advantage due to the expansion of the genetic material. Gardeners know that first-generation (F1) hybrids obtained by cross-pollination of different varieties are superior in many respects to “pure” varieties.
Self-pollination is possible in plants with bisexual flowers, which are 75% in nature. These are, for example, tomatoes, peanuts, peas. But this is not the best option, rather a backup.
Plants fight self-pollination. They also want progress. Some - by non-simultaneous ripening of stamens and pistils (apple and pear), others - by different heights of stamens and pistils (lungwort, buckwheat), still others - by self-sterility (cherry, red clover), fourth - by heterosexuality (sea buckthorn, actinidia).
Self-cross pollination, for all its advancedness, is tied to an intermediary. It can be wind (cereals, conifers, birch, hazelnuts, alder), or it can be insects, birds and even bats. The majority of insects are insects.
So that the ripened pollen is not wasted, flowering plants have "developed" many ways to attract insects and ensure pollination. Bright flowers, sticky pollen, attractive scent, sweet nectar, comfortable landing sites. Most often, these methods work.
Some plants have taken the path of cooperation with specific insects. For example, clover - only long-trunk insects can pollinate it: bumblebees and some types of bees. The massive death of bees in recent years and the decline in the bumblebee population have shown that this was not a good idea.
Who helps the plants?
The existence of the vast majority of flowering plants (almost 90% of species) is already impossible without pollinating insects. At the same time, bees perform a significant proportion of intermediary work. It turns out that honey and beekeeping products on a global scale are by-products in the activities of bees. The most significant work of the humming toilers is pollination and ensuring the harvest.
Bee pollination, by the way, is the cheapest method of increasing yields, incomparable in efficiency with any agrotechnical methods. In addition, bees contribute to productivity not only in terms of getting the products people need, but, most importantly, they provide biological diversity.
We are talking about those bees that are in apiaries, and about a huge number of wild species, both solitary and public. In general, there are about 21 thousand species and 520 genera, common on all continents, except Antarctica. Bumblebees are part of the family of real bees. Wasps are not included, but also good pollinators.
Many plants pollinate butterflies, often those with nectaries at the base of a long, narrow tube of corolla or spur (honeysuckle, buddleia). Daytime butterflies prefer bright colors - red, orange, purple. Moths pollinate sweet-smelling light-colored flowers late in the evening and at night (scented tobacco, for example).
Late in the evening, hawk moths attack the Japanese honeysuckle 'Halliana' blooming and smelling of 'Today' by Avon. Hang over the flowers. An enchanting sight at dusk, accompanied by a dizzying scent.
Pest butterflies make up only 2% of the population, the rest (or rather, their children) do not eat anything significant.
Beetles are good at pollinating large flowers, such as rose hips, liliaceae, or small ones in inflorescences, like dogwood, elderberry, umbrella. The sense of smell in beetles is better developed than sight, so plants attract them with sweet smells - fruity, spicy, or the smell of fermentation. But the color of plants pollinated by beetles is dim.
By the way, bees see not at all the way we do. They do not perceive red as red; they distinguish well between white, yellow, and blue. On such flowers, bees are most often found. I have a working bright yellow suit, and on the site bees often fly up to me asking: how can you profit from such a big and yellow one?
Ants make their own contribution to the pollination of the umbrella, which they gladly climb for sweet nectar. They also pollinate pumpkin seeds well - there is also sweet nectar, and you don't need to climb high.
Flies, leafhoppers and a lot of all sorts of little things that we don't even pay attention to also participate in pollination. But the bees have the palm.
Boundary conditions and force majeure
If the flowers have blossomed, this does not mean that there will be a harvest. The most significant factor is the weather during flowering. For example, hazelnuts bloom very early in the Kuban and Crimea: in late January – early February. Its northern sister - hazel - blooms in April. The principle is the same, in nature everything is provided. At daytime temperatures above +12 ° C in dry weather, male catkins grow at an incredible speed, anthers crack from dry air and throw up to 4 million pollen grains into the wind, each (!) Earring.
"Dusting" lasts 1-2 weeks, while the female flowers are open for more than two weeks and, it seems, must be pollinated. But the weather is tricky and insidious, even meteorologists only guarantee relative accuracy for five days. There may be prolonged rains. Or snow, for example. What happened this year. Wet weather for two weeks will nullify Walnut's demographic record efforts.
This spring in the Kuban generally demonstrates sophisticated deceit: since the beginning of March, the temperature is + 22 ° C in the shade for more than a week. Apricots in an emergency order began to drive juices through the tree and opened flowers. As soon as the flowers opened, the night temperature dropped to -7 ° C. We no longer wait for apricots, open flowers can only withstand -1.5 ° C. For most fruit, with open flowers, temperatures of -2 ° C are critical, in buds -3 ° C, the ovary will withstand -1 ° C.
These are not all possible troubles. In wet and cold weather (below +12 degrees), bees will not fly during flowering: the energy costs for flying and collecting nectar or pollen are not justified. Accordingly, there will be very few pollinated flowers. But they will be, because flies, thrips, white-eyed and at this time still roam the flowers, although not as effectively as bees.
The sun and the unexpected spring heat during flowering are even worse: at high temperatures, wind and dry air, the stigmas of the pistils dry out in the flowers, the pollen grains germinate poorly and the ovary is formed with defects or does not form at all.
Plants, of course, reinsured against 1-2-3-day weather troubles: in pome fruits, the susceptibility to fertilization is extended by 9-10 days, in stone fruits by 5-6 days, in berries by 6-7 days. So there is a chance.
It goes without saying that a cross-pollination garden should have at least 2-3 simultaneously flowering plants of each species. If not, you need to plant other varieties in the crowns of trees, plant pollinators or stimulate your neighbors to start gardens.
Pollination of vegetables
Vegetables are even more interesting: low night temperatures (below + 12 ° C) during the flowering period in our favorite nightshade greatly reduce the viability of pollen. High temperatures (above +40 ° C, which is not uncommon in greenhouses) lead to a complete loss of pollen viability. The lack of air movement also reduces the pollination of nightshades. And this despite the fact that the nightshade are self-pollinated!
The situation is more difficult for monoecious pumpkins: pollen from a male flower must be dragged to a female one, and here insects cannot be avoided. It's good that there are parthenocarpic cucumbers, but what should zucchini and pumpkins do? In cool and damp weather, you can often see a small ovary of a pumpkin or vegetable marrow rotting. This is evidence of insufficient pollination. Bees and bumblebees do not fly in this weather, and the ants, which also pollinate the pumpkin seeds, brought in immature pollen.
How can we help plants to pollinate?
The most important thing is to attract bees and bumblebees to the site. It is better to have your own bees, but if circumstances do not allow, you can use strangers and wild ones. The main thing is that they get used to flying to the site. Most of the flowering spring plants that delight the gardener's eye are not interesting to bees. But there is a hum over the weedy tree, and bees with bumblebees sit on almost every flower.
Dandelions are also good baits. Also the clover is white. For red clover, not all bees have the length of the proboscis. But bumblebees fly well at him. By the way, when white clover blooms, our bees even ignore the phacelia. Umbrella are attractive to all insects. Let carrots, parsley, cilantro, celery, parsnips and lovage bear fruit - you can also harvest the seeds. Angelica can be entered into a flower garden. Perennial onions, both edible and decorative, are extraordinarily good at attracting pollinators.
Spraying with insecticides at the beginning and during flowering is completely unacceptable
If there are no herbaceous melliferous plants and the bees ignore the garden, you can sprinkle it with preparations that attract them - "Ovary" or "Perfumer". Well, since the first thing that bees react to is color, you can attach something round bright yellow in the crown of a tree or bush. The bees, if they have already flown in, will definitely inspect the surroundings.
You won't be able to fight the weather; you can only slightly weaken its negative influence. Smoke in the garden during the flowering period can raise the temperature by a degree or two and preserve the generative organs of plants. Sprinkling too. Late in the evening, you can spill abundantly the ground under the trees - the resulting fog will also somewhat improve the situation. If the plants are small, then it's better not to come up with anything covering materials.
In the greenhouse in the heat, you need to arrange ventilation, for self-pollinated plants this is important. It is a good idea to sometimes shake the stems of flowering tomatoes, peppers and eggplants so that pollination goes on more actively.
If the situation with tying pumpkin seeds is depressing, you can “work as a bee”: pick a male flower and poke a female one. To guarantee, it is best to pollinate with two or three male flowers. Among all this pollen, the flower will choose the leader.
Dear Readers! Ideally, when flowers are pollinated by insects, they have long cooperated and adapted to this. Little creatures that people constantly harass in one way or another do a great job of preserving the green blooming world. Take care of them!