Effect of fungal toxins on germination of Striga hermonthica seeds

Fourteen fungal toxins were assayed in vitro to evaluate their effect on seed germination of the parasitic weed Striga hermonthica. Among them, T‐2 toxin proved to be the most active, being able to inhibit 100% seed germination at 10−5 M, and being still active when tested at a concentration of 10−7 M (19% inhibition). Deoxinivalenol was also very active, causing 100% and 69% reduction in germination when assayed at 10−4 and 10−5 M respectively. Cytochalasin E, tenuazonic acid, fumonisin B1, enniatin and nivalenol were shown to have an inhibitory effect of around 50% at 10−4 M, whereas other toxins had lower or no activity. The high activity shown by some fungal toxins suggests that they may have potential for use as more natural and safe herbicides to suppress parasite seed germination.