Brown root rot of tomato, and its control, in Crete

SUMMARY Symptoms similar to those regarded as typical of brown root rot disease have been noticed in tomato and eggplant in Crete. Infected plants showed symptoms only during the winter. Three fungi Pyrenochaeta lycopersici, Colletotrichum coccodes and Fusarium oxysporum were consistently isolated from infected tomato roots and proved to be pathogenic to young tomato seedlings. Pycnidia of P. lycopersici were produced when small pieces of infected young tomato roots were plated out on tomato juice agar (Oxoid) and incubated at 23 °C under continuous white light. Good control of the disease was achieved when soil was fumigated with dazomet 98% (70g/m2), methyl isothiocyanate (MIC) 20%+ dichloropropane-dichloropropene mixture (DD) 80% (-Di-Trapex; 50 ml/m2), methyl bromide (75 g/m2), and vapam (200 ml/m2) + ethoprophos 10% (10 g/m2) or when solarisation was applied (soil covered by 50 μm transparent polyethylene sheet) during the whole period of August and September. Dazomet (30 g/m2) or ethoprophos 10% (10 g/m2) when combined with solarisation did not improve its effectiveness. MIC 20%+ DD 80% emulsified (Di-Trapex e.c, 50 ml/m2) was ineffective.