Allelopathy: Mechanisms and Applications in Regenerative Agriculture

Allelopathy is an important mechanism in plant communication and interference, involving the release of plant/microorganism self-produced, special featured organic molecules into the environment. These molecules (allelochemicals) inhibit or stimulate the growth of neighbored plants and microorganisms (targets), depending on their type and dosage. They are therefore regarded as natural plant growth modulators, with the effects also influenced by the developmental and other characteristics of the target plants. When used as a form of negative interaction between species, allelopathy in agriculture serves as a proven, sustainable tool for integrated weed control in organic farming, thereby mitigating environmental risks, a key objective of the Green Deal and Farm to Fork Strategy of the EU Agricultural Policy. Allelopathy can reduce the use of synthetic herbicides or of chemically upgraded natural compounds which cannot be no longer considered natural products. The adoption of allelopathy (plant-plant and plant-microbe interactions) in regenerative agricultural practices still requires thorough multidisciplinary research (encompassing chemistry, genetics, metabolism, and agronomy) to address two complementary areas of focus. First, screening is needed to identify new allelopathic plants and their allelochemicals. Second, it is crucial to investigate the agronomic feasibility of effectively using these plants and their metabolites in conventional agroecosystems through field studies. For the latter, it is important to assess the potential for incorporating these allelopathic plants into crop rotations, often as cover crops, without adversely affecting subsequent crops.