Stemphylium

The ripe tomatoes fruits present a good medium for the formation of many phytopathogenic and saprophytic microorganisms. One of such microorganisms, that is growing in the wide range of temperatures (4-35ºC), is the fungus Stemphylium botryosum Wallroth (Deuteromycotina).

Infection is mainly through stomata and wounded surfaces of the plant. The fungus is confined to both leaves and fruits: the former show brownish spots, the latter – white-grayish mycelium that makes up a colony 1-2 cm diam. (fig. 1). It darkens quickly turning into dark gray, brownish and nearly black