Efectos alelopáticos de rastrojos de cultivos de servicio en la supresión de malezas problemáticas

The present study aimed to evaluate the allelopathic potential of residues from three cover crops Avena strigosa (black oat), Secale cereale (rye), and Vicia villosa (hairy vetch) in the suppression of the weeds Amaranthus palmeri (Palmer amaranth), Echinochloa colona (jungle rice. Bioassays were conducted under controlled conditions using aqueous extracts obtained from the aerial and root parts of each species. Results showed that oat exhibited the highest inhibitory capacity on both weed species and Lactuca sativa used as an indicator species, with significant reductions in root and hypocotyl length, in some cases even surpassing the herbicide control. Vicia villosa also showed a reduction effect, particularly on A. palmeri, with root extracts standing out for their activity at low concentrations. Secale cereale, in turn, displayed a strong allelopathic potential on the indicator species (L. sativa), although it had a lower effect on A. palmer iand no effect on E. colona. The results confirm that these cover crops mainly oat contain compounds with inhibitory capacity that could contribute to weed suppression, complementing the physical effect of crop residues within integrated weed management. Further field studies are needed to determine whether these laboratory findings can be reproduced under real production conditions.