EFFECTS OF SOME FUNGAL ISOLATES ON GERMINATION AND HAUSTORIUM INITIATION OF STRIGA HERMONTHICA (DEL.) BENTH

Two laboratory experiments were conducted to assess the effects of fungal isolates on germination and haustorium initiation of Striga hermonthica. Forty three fungal isolates were isolated from infested and un-infested sorghum fields with Striga hermonthica. A preliminary screening was conducted to assess the effect of these isolates on germination of preconditioned Striga seeds. Sixteen fungal isolates in addition to a standard strain Trichoderma viride were selected according to their effects on Striga seeds germination and haustorium initiation. In the first experiment isolates and strain were assessed for their effect on germination of Striga seeds during conditioning in response to GR24. The second experiment was conducted to study the effects of fungal isolates and T. viride on Striga haustorium initiation. The results revealed that six fungal isolates had no effects; six isolates reduced germination (34-93%) significantly while other isolates significantly enhanced germination (15–59%) of Striga seeds. Moreover, isolate Ai 41 reduced germination over 90% as compared to the corresponding control. Similarly, few fungal isolates inhibited haustorium initiation while some had no effect. Isolate Ai 50 was the only isolate that completely (100%) inhibited haustorium in response to DMBQ. The study concluded that some fungi can be used as control agents against Striga and suggested that further studies had to be conducted in the green house and field to verify theses results and develop a strategy for the use of fungi as mycoherbicides against Striga.