Assessment of weed root extracts for allelopathic activity against Orobanche and Phelipanche species

Broomrapes (Orobanche and Phelipanche species) are holoparasitic weeds that infect roots of crop hosts from Asteraceae, Brassicaceae, Apiaceae, Fabaceae, Solanaceae. The parasitic difficult to control selectively without damage once attached their roots. Identification natural compounds with herbicidal activity against pre-attached broomrape stages can provide alternatives. With the aim identify plant species efficacy for control, organic residual aqueous phase extracts seventeen weed common in south Spanish broomrape-infested fields were assessed as potential inducers suicidal germination inhibitors radicle growth. Assessments carried out vitro using seeds seedlings four noxious species, Orobanche crenata Forsk., cumana Wallr., minor Sm. ramosa (L.) Pomel. While root all did not induce on O. seeds, most induced P. except those obtained Amaranthus albus L., retroflexus L. Convolvulus arvensis Moderate levels by some tested, strongest induction Heliotropium europaeum Silybum marianum Gaertn. seeds. For extract inhibition radicles, C. strongly inhibited radicles species. other low or negligible growth, many radicles. Exceptions Datura stramonium Malva sylvestris Solanum nigrum Urtica dioica which inhibit A. retroflexus, Portulaca oleracea S. nigrum, Among active assessed, showing promising chemical profiles selected future studies characterize early