Crop Allelopathy for Sustainable Weed Management in Agroecosystems: Knowing the Present with a View to the Future

Abstract

In the face of yield losses caused by weeds, especially in low-input agricultural systems, and environmental pollution due to the excessive use of synthetic herbicides, sustainable weed management has become mandatory. To address these issues, allelopathy, i.e., the biochemical phenomenon of chemical interactions between plants through the release of secondary metabolites into the environment, is gaining popularity. Although many important crops are known for their allelopathic potential, farmers are still reluctant to use such knowledge practically. It is therefore important to assist advisors and farmers in assessing whether allelopathy can be effectively implemented into an eco-friendly weed management strategy. Here, we aim to give a comprehensive and updated review on the herbicidal potential of allelopathy. The major findings are the following: (1) Crops from different botanical families show allelopathic properties and can be cultivated alone or in combination with other non-allelopathic crops. (2) Many allelopathic tools can be adopted (crop rotation, intercropping, cover cropping as living or dead mulches, green manuring, use of allelochemical-based bioherbicides). (3) These methods are highly flexible and feature increased efficiency when combined into an integrated weed management strategy. (4) Recent advances in the chemistry of allelopathy are facilitating the use of allelochemicals for bioherbicide production. (5) Several biotechnologies, such as stress induction and genetic engineering techniques, can enhance the allelopathic potential of crops or introduce allelopathic traits de novo. This review shows how important the role of allelopathy for sustainable weed management is and, at the same time, indicates the need for field experiments, mainly under an integrated approach. Finally, we recommend the combination of transgenic allelopathy with the aforementioned allelopathic tools to increase the weed-suppressive efficacy of allelopathy.

Allelopathic Activity of a Novel Compound, 5,6-Dihydrogen-11α-O-acetyl-12β-O-tigloyl-17β-marsdenin, and a Known Steroidal Glycoside from the Leaves of Marsdenia tenacissima (Roxb.) Moon

“…Herbicides are powerful tools for controlling weeds. However, improper and long-term use of herbicides not only negatively affects human and environmental health but also cause an increase in herbicide-resistant weeds [3,4]. To avoid these effects, investigating allelochemicals from potent allelopathic plants has become crucial in the search for weed control alternatives to synthetic herbicides [5].…”

Inuloxin A Inhibits Seedling Growth and Affects Redox System of Lycopersicon esculentum Mill. and Lepidium sativum L.

“…Over the last decades, the increasing herbicide-resistant weeds and public concern about human health and the environment caused by the widespread use of synthetic herbicides, has made the use of sustainable weed management mandatory [ 40 , 41 ]. Much effort has been focused on natural compounds with an emphasis on new chemicals involved in plant–plant interactions for the discovery of potential herbicides [ 15 , 42 ].…”

Toward the Allelopathy of Peganum sp. and Related Chemical Constituents in Agriculture

“…The time of decomposition before seeding is also a valuable parameter to consider recalling that the efficacy of the plant residue decreases with the increasing time of decomposition (Xuan et al, 2005;Sampietro et al, 2007). In addition, crop rotation practices, inter-cropping, and mulching all involve the application of allelochemicals in agroecosystems (Scavo and Mauromicale, 2021).…”