Plants unlike animals and humans can’t move or communicate. For humans they are life sustaining organisms standing quietly in a specific place from many years, decades and centuries. Their existence is much ignored by us, until we get to know something new and uncommon about them. One of the unknown facts about them is their ability to produce certain compounds which inhibit or kill the adjoining plants or seedlings in order to reduce the competition. This weird phenomenon is called Allelopathy.
There are certain and specific plants which exhibit allelopathy. So, in this post let’s know about some of those plants which possess such unique power of suppressing their enemies.
10 Plants that show Allelopathy
- English Laurel (Prunus laurocerasus)
The English Laurel plant has a substance called ‘Cynolipid’, made up of cyanide and lipids, in its leaves, fruits and seeds. The substance when come in contact with other plants, especially seedlings, it act as a poison and restrain their growth.
- Rhododendron (Rhododendron poniticum)
Rhododendron tree too exudates certain poisonous substances from their roots that suppresses the growth of adjoining seedlings by altering the seed germination, root elongation and mycorrhizal colonization.
- Black Walnuts (Juglans nigra)
The Walnut tree produce a compound called ‘Juglone’ from its buds, leaves, nut shells and roots. The substance affects growth of adjoining plants such as tomatoes, peppers, eggplant, potato, pine and birch.
The Eucalyptus tree too affects the seed germination, growth of seedlings and root length of cotton and wheat growing in its vicinity. The foliage and leaves of the tree have compounds that are found to be having inhibitory effect on other plants.
- Garlic Mustard (Alliaria petiolata)
The grass or weed produces a poisonous substance called ‘Ailanthone’ from its roots. It affects the roots of the neighbouring plants and alters their mycorrhizal association.
- Marigold (Tagetes minuta)
The plant with beautiful flowers not only produces aromatic compounds but also poisonous substances from its roots. It produces alpha-terthienyl from the roots which kills nematodes and hinders the growth of adjoining plants.
- Pine (Pinus roxburghii)
The pine tree produces phenols and esters which get transferred to the ground through its foliage. Through leaching and decomposition, the compounds get mixed with soil making it acidic which helps the tree to check the growth of its competitors in the area.
- Casuarina (Casuarina equisetifolia)
The Casuarina trees also produce Terpenes and Phenols, just like pines and other allelopathic trees, which are natural tannins and carcinogenic. These compounds are present in roots, stems, needles, fruits and seeds of the plant that help the tree to check the growth of competitors.
- Asparagus (Asparagus officinalis)
The Asparagus plant inhibits the growth of any other plant and even its own seedlings from its space by producing certain amino acids, phenolic acids, ferulic acids and saponins.
- Leucaena (Leucaena leucociphala)
The substance present in the Leucaena roots, leaves and foliage reduces the productivity of the field crops such as wheat and turmeric. So, it is advised to avoid the combination of the two for progressive farming.