Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Plants as sources of natural herbicides against branched broomrape (Orobanche ramosa L.).

Abstract

Studies on possible role of allelopathy in controlling branched broomrape (Orobanche ramosa), through screening different plant species, including summer and winter plants, traditionally known as non-host crops, medicinal herbs, and a large number of common weed species for possible effect of their root exudates released into the soil on the parasite's ability to attack the following tomato plants (as a preferable host crop) revealed great variation between species in their abilities to stimulate germination, growth and development of the parasite on the following tomato plants. Tomato grown after Datura metel, Brassica spp., Eruca sativa, Lupinus alba, Raphanus sativus, Spinacia oleracea, Hibiscus sabdariffa, and Salvia officinalis showed significantly low O. ramosa infestation. However, reduction in parasite infestation obtained after certain tested species may be due to their allelopathic effect on tomato plants. Dried shoot residues of different weed species incorporated into Orobanche ramosa infested soil, showed that certain weed species highly stimulated parasite germination and infestation to tomato plants; others reduced or almost completely prevented infestation. Shoot residues of Chenopodium amaranticolor, Chenopodium murale, Ecballium elaterium, Leontodon tuberosa, Malva sylvestris, Sacropoterium spinosa, Suaeda asphaltica, and Smilax aspera greatly reduced parasite infestation, while those of Althea rosa, Anthemis cotula, Astragalus oocephalus, Avena sterilis, Bryonia cretica, Capparis spinosa, Centaurea iberica, Cichorium intybus, Convolvulus althaeoides, Convolvulus arvensis, Convolvulus dorycnium, Conyza bonariensis, Echinops ritro, Epilopium angustifolium, Eryngium glomeratum, Euphorbia macroclada, Euphorbia allepica, Lantana camara, Launea nudicaulis, Lephechloa pumila, Molucella leavis, Ononis natrics, Onopordon anisacanthum, Onopordon macrocephalum, Osyris alba, Papaver rhoeas, Polygonum aviculare, Portulaca oleracea, Rubus tomentosus, Satureja thymbra, Satureja thymbrifolia, Senecio vernalis, and Sinapis arvensis encouraged and increased parasite infestation. Results showed the importance of certain plants as trapping or catching species for the parasite and the potential effects of their root exudates and/or residues on Orobanche ramosa.