Dispersal of Synchytrium psophocarpi in Papua New Guinea

Airborne sporangia of Synchytrium psophocarpi showed a diurnal periodicity, maximum numbers occurring between 1600 and 1800 h and minimum numbers between 0600 and 0700 h. There wers significant correlations between the amounts of airborne sporangia and temperature (positive), relative humidity (negative) and dew (negative). The numbers of airborne sporangia increased following the onset of the wet season (November—April) but declined after the onset, of the dry season (May—October). Most airborne sporangia appeared to deposit within 15 m of their source. The potential for dispersal of sporangia by rain splash was demonstrated.