A severe outbreak of crown and root rot of tomato caused by Fusarium oxysporum f. sp. radicis-lycopersici in Malta

摘要

A severe outbreak of crown and root rot of tomato was observed in greenhouses in Malta in eight locationsudduring the period November 2004 – February 2005. Besides root and crown symptoms, several plants showedudcankers at the basal part of the stem. Fusarium oxysporum was constantly isolated from these plants. One isolateudfrom each location was tested for pathogenicity on tomato seedlings. All these isolates caused severe necrotic lesionsudof the crown and roots, and stem cankers. It was concluded that F. oxysporum f. sp. radicis-lycopersici (FORL) wasudthe cause of the outbreak. Incidence ranged from 10 to 50%. Cold weather conditions occurring in Malta during theudlate fall and winter of 2004–2005 probably favoured the disease. The use of tomato cultivars or hybrids resistant toudFORL is suggested for winter tomato crops in south Mediterranean areas.