A promising Fusarium graminearum isolate has been evaluated as a potential biocontrol agent of two important aquatic weeds, Egeria densa and E. najas. This work aimed to study the effects of photoperiod and temperature on the control of these plants under laboratory conditions. The symptons in the plants inoculated with F. graminearum were evaluated every two days, with disease severity being evaluated through a grade scale and plant growth by fresh weight gain, expressed in percentage. The highest severity grades were observed whin both species were kept in the dark and the lowest under 12 hours photoperiod. The temperature of 30 ºC provided the higest disease severity for both species. The species E. densa presented the highest fresh mass production under 12 hours of light and at temperatures belou 25 ºC, and the lowest production in the dark and at temperature of 30 and 35 ºC, while E. najas presented lower fresh mass production in the dark and at temperatures fron 25 to 35 ºC.
biocontrol; aquatic weeds; abiotic factors
