Australia: The Land Where Time Began

A biography of the Australian continent 

Allelopathy

Some plants, algae, fungi, bacteria, corals and bacteria, produce compounds, allelochemicals, secondary metabolites, that, when released into the environment, as when excreted into soil, inhibits the germination and growth of other plants. The effects are usually on different species, but also in some cases it inhibits the germination of its own seeds if they are too close to the plant producing the allelopathic substance.

The term allelopathy was coined by Molisch (1937) to refer to biochemical interactions between all types of plants, including microorganisms. In his discussions he indicated that the term referred to both detrimental and beneficial reciprocal biochemical interactions. The meaning of the Greek words it was derived from actually mean mutual harm.

Rice suggests that the term should apply to any harmful effects, direct or indirect, by one plant, or microorganism, on another through the production of chemical compounds released into the environment. Rice also distinguishes allelopathy from competition that involves removal or reduction of a factor required by other plants from the environment, such as water, minerals, foods and light. Since Rice's book was published the use of the term allelopathy changed to include positive and negative effects on other plants, but then swung back to the original meaning, negative effects. The term has been borrowed by authors on zoology to refer to interactions between invertebrates.

Sources & Further reading

Rice, Elroy L., 1974, Allelopathy, Academic Press, New York, Sanfrancisco, London