BIDIRECTIONAL ALLELOPATHIC INTERACTIONS OF RADISH (RAPHANUS SATIVUS L.) AND OTHER CROPS

Abstract

Allelopathy, the biochemical interaction among plants mediated through the release of secondary metabolites, has emerged as an important ecological phenomenon with significant implications for sustainable agriculture and integrated crop management. Among vegetable crops, radish (Raphanus sativus L.), a member of the Brassicaceae family, is recognized for producing a diverse array of bioactive compounds, including glucosinolates, isothiocyanates, phenolic acids, and flavonoids, which influence the germination, growth, and physiological performance of neighbouring plant species. Conversely, radish itself is susceptible to allelochemicals released by weeds, crops, and cover plants, highlighting the bidirectional nature of allelopathic interactions within cropping systems. This review synthesizes current knowledge on the allelochemicals produced by radish, their modes of release, and their biological effects on agricultural crops, weeds, and associated plant communities. It further examines the allelopathic impacts of other plant species on radish, emphasizing their influence on seed germination, seedling establishment, growth, and productivity. The review also discusses the environmental, biological, and management factors that regulate allelopathic activity, including soil properties, climatic conditions, microbial transformations, plant developmental stage, and allelochemical concentration. In addition, existing knowledge gaps are identified, particularly the limited availability of field-based investigations, insufficient characterization of allelochemicals in tropical radish germplasm, lack of standardized experimental methodologies, and the underutilization of modern omics approaches for elucidating allelopathic mechanisms. By integrating evidence from studies investigating both the donor and receiver roles of radish, this review provides a comprehensive understanding of bidirectional allelopathic interactions and their ecological and agronomic significance. The information presented is expected to support future research aimed at developing sustainable weed management strategies, optimizing crop rotation systems, and improving environmentally friendly vegetable production.