The use of soil born bacteria as substitute to chemical herbicides for control of Striga hermonthica infesting sorghum

摘要

A series of laboratory and green house experiments were conducted to study the effects of some soil borne bacteria on germination,haustorial initiation,attachment and successful parasitism in S.hermonthica on sorghum.A total of 210 bacterial strains and isolates were screened.Some bacterial isolates and strains viz Pseudomonas putida,Azospirillum brasilense,Bradyrhizobium japonicum and Azotobacter amazonas inhibited germination by 2 to 26％.Incubation of conditioned S.hermonthica seeds over a medium inoculated with a Klebsiella sp.induced considerable germination (34 and 49 ％).However,unconditioned seeds were not stimulated.Isolates G18,G11,D2,G8,GSL,D25ok,and Azotobacter inhibited haustorial initiation (20-69％).The isolates G 18,B3,G11,G8C,M2,GSL,M20,G18(x),M34,S23,S 10,S 19,Azotobacter,A.brasilense,Bradyrhizobium curtailed haustorium initiation (21-74％) in response to root macerate,while GSL,S22,G14 isolates and strains P.