Biological control of gooseweed (Sphenoclea zeylanica Gaertn.) with an Alternaria sp. uri icon

abstract

  • Greenhouse and field experiments at the International Rice Research Institute (IRRI) evaluated the potential of a leaf blight pathogen (Altemaria sp.) for the control of gooseweed, Sphenoclea zeylanica Gaertn. In greenhouse experiments, S. zeylanica plants at all growth stages, from seedlings to flowering, were killed by the pathogen when applied as conidial suspensions of 6.3 x 10(3) to 1.4 x 10(6) conidia ml(-1) over a range of dew period durations. Field trials confirmed the effectiveness of the Alternaria sp. to control S. zeylanica under varying environmental conditions. Concentrations of 10(5)-10(6) conidia ml(-1) applied at 50 ml 0.25 m(-2) gave good control of gooseweed, reducing weed density by 80-99% and weed biomass by over 90% in all trials. The Alternaria sp. did not affect rice or other non-target species present in the field plots.

publication date

  • 1995
  • 1995
  • 1995