The fungus A Itemaria e ichhomiae isolate #5 (Ae5) is being developed as a
mycoherblcide agent for controUlng water hyacinth (Eichhomia crassipes) in Egypt.
Inoculum concentrations above 10% (mycelial wet weight) were equally effective in the
management of water hyacinth. There was an inverse relationship between the fungal
culture age (up to 9 week old) and inoculum infecUvily; the younger mycelial inoculum
was more virulent on the weed plants than older ones. Applications 0 f A e5 ina n
aqueous carrier and/or in nine different invert/oil emulsions were evatuated for the
biocontrol of water hyacinth without a post·treatment dew period under natural (outdoor)
conditions. The invert/oil emulsions were developed to provide moisture and to retard
evaporation from the fungal inoculum applied so that the fungal propagules could
germinate and Infect the target weed under relatively dry conditions. All of the invert
and/or oil emulsion formulations induced higher levels 01 cisease on water hyacinth
plants when compared to the aqueous suspension formulatiCJI. under dew.free
conditions. RedUCing the oil content in the Ae5 emulsion formulati0!ftrom 30 to 5% had
no significant effect On the formulation's infectivity against wate~ hyacinth. In the
absence old ew, A e5 f onmulated inc ottonseed 0 iI emulsion caused 1 00% control of
water hyacinth in the outdoor field plots 7 to 13 weeks after applicatiOn. Thus, the
results confirm the utl1ity and feasibility of oil emulsions as formulating materials for
bioherblcides under the lack of dew conditions.