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Allelopathy: what is it, types and examples

A phenomenon that many people are unaware of is that nearby organisms have the ability to communicate or interact with each other through chemical compounds. This is what is called allelopathy and, for example, a very simple case is the relationship between plants that are close to each other in an orchard. This is known as a crop association and also serves for organic pest control in plants.

In this AgroCorrn article we will see more about allelopathy: what it is, its types and examples .

You may also be interested in: Apomixis: what it is, types and examples
  1. Allelopathy: what is it
  2. Types of allelopathy
  3. Allelopathy: examples

Allelopathy: what is it

The simple definition of allelopathy is that it is a biological phenomenon in which an organism generates biochemical compounds that influence the survival, growth or reproduction of other organisms. These compounds can represent beneficial effects ( positive allelopathy ) or harmful ( negative allelopathy ) for the recipient organisms. Among these compounds are aliphatic compounds such as acids or alcohols, lipids, fatty acids, terpenes or aromatic compounds. The release of the compounds can occur in volatile form, through leachates or exudates from their roots. The effect of allelopathy is not total for good or bad, but varies in degrees according to the characteristics of the organisms involved.

The organic farming takes good advantage of this phenomenon in protecting crops certain insects or pests by placing aromatic plants, such as placing rough near potato crops. Here we explain more about how to combat pests in organic farming with this technique and others.

There are natural products that are used for their biological characteristics such as pesticides, herbicides, growth inhibitors or stimulants, and antibiotics. The effects of these products are varied, such as the inhibition of germination, the inhibition or stimulation of the growth of neighboring plants, avoiding the actions of insects and leaf-eating animals or preventing the harmful effects of viruses, bacteria and fungi. Natural products are an important part of the defense mechanisms of plants and are biodegradable.

Types of allelopathy

Among the types of allelopathy are those that occur between fruit trees, which is known as autotoxicity or auto-allelopathy , and those that occur between herbaceous plant species on fruit species or heterotoxicity .

Biological control with plants has long been used in agriculture to repel or attract insects, worms, and other disease agents. Examples of commonly used plants are aromatics, vegetables, medicinal plants and “weeds”. The types of biological pest control that are generally used are repellent plants, companion plants or trap crops.

Companion plants

They are also known as related plants and provide mutual benefit to other plants. These benefits can be in the germination of the seed, development and growth or, even, in the taste and aroma of the final crops. Related or companion plants must be planted in the vicinity of the crop so that their emitted substances are absorbed by the other plant. For example, nettles close to aromatic plants lead to an increase in their aromatic quality.

Repellent plants

These are plants that with their strong aroma keep insects away from crops. There are plants that are specific to a specific type of insect and others that are more general. These plants can be planted inside the crop or bordering it as a protective barrier and have an area of ​​influence of up to 10 meters away.

Trap crops

These are plants that attract harmful insects away from the main crop. These are sown around the perimeter of the crop to be protected, or also between the other plants, to concentrate the pests and later trap and eliminate them. Another use of these plants is to help reproduce predators or parasites of pests that affect the garden.

Image: Google Sites

Allelopathy: examples

Some examples of allelopathy that we can cite in each of the groups are:

Companion plants

  • Garlic with onions, strawberries, lettuce or tomatoes.
  • Celery with cabbages, beans, leeks, or tomatoes.
  • Peppers with aubergines, parsley, tomatoes or lettuce.
  • Potato with garlic, calendula, beans or celery.
  • Onions with beets, cucumbers, tomatoes or carrots.
  • Tomatoes with garlic, basil, leeks or carrots.

For more examples of this type, you can consult this other AgroCorrn article on Vegetables that grow well together .

Repellent plants

  • Basil acts as a repellent against spider mites, whiteflies or aphids.
  • The mint acts as a repellent against ants, whiteflies or mice.
  • Oregano repels ants, flies or aphids.
  • Sage repels cabbage butterflies, whiteflies or aphids.

Trap crops

  • Dill attracts earthworms.
  • Ivy attracts bed bugs and mites.
  • Mustard attracts foliage-eating worms.
  • Tobacco attracts whiteflies.
  • Clover attracts the cabbage fly.
  • Rue attracts flies and moths.

Below you can see a video that deals with this interesting topic of plant communication.

Image: Google Sites

If you want to read more articles similar to Allelopathy: what it is, types and examples , we recommend that you enter our Biology category .

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