Chemically mediated plant-plant interactions, including allelopathy and allelobiosis, are crucial for plant coexistence and community assembly. Allelopathy involves the release of allelochemicals to inhibit neighboring plants, while allelobiosis involves signaling chemicals for neighbor detection and identity recognition. These processes are essential for plant survival and community dynamics. Allelopathy and allelobiosis are closely linked and occur together in plant-plant interactions. Recent studies highlight the importance of allelopathy in sustainable agriculture and forestry, particularly in managing invasive species and improving crop yields. Allelobiosis, involving chemical signals for neighbor recognition, plays a key role in plant-plant signaling and identity recognition. Root exudates and soil-borne signals are critical for belowground interactions, influencing plant growth and competition. Understanding these interactions helps in developing strategies for sustainable agriculture and ecological management. The review emphasizes the need for further research into the molecular mechanisms and ecological significance of allelopathy and allelobiosis in plant-plant interactions.Chemically mediated plant-plant interactions, including allelopathy and allelobiosis, are crucial for plant coexistence and community assembly. Allelopathy involves the release of allelochemicals to inhibit neighboring plants, while allelobiosis involves signaling chemicals for neighbor detection and identity recognition. These processes are essential for plant survival and community dynamics. Allelopathy and allelobiosis are closely linked and occur together in plant-plant interactions. Recent studies highlight the importance of allelopathy in sustainable agriculture and forestry, particularly in managing invasive species and improving crop yields. Allelobiosis, involving chemical signals for neighbor recognition, plays a key role in plant-plant signaling and identity recognition. Root exudates and soil-borne signals are critical for belowground interactions, influencing plant growth and competition. Understanding these interactions helps in developing strategies for sustainable agriculture and ecological management. The review emphasizes the need for further research into the molecular mechanisms and ecological significance of allelopathy and allelobiosis in plant-plant interactions.