REACTION OF CUCUMIS MELO CULTIVARS TO RACES OF FUSARIUM OXYSPORUM F.SP. MELONIS THE CAUSE OF MELON VASCULAR WILT

During 1970-1985, reaction of 180 cultivars of Cucumis melo including cantaloupe, long-melon, snake melon, and dudaim collected from various parts of Iran and other countries were evaluated against races 0, 1, 2 and 1, 2 of Fusarium oxysporum f. sp. melonis using different inoculum potential under greenhouse conditions. Many of the Iranian cultivars were resistant to races 0 and 2 which have not been reported yet from Iran. Few cultivars were found to be resistant to race 1 prevalent in Khorasan and Semnan provinces. None of the Iranian cultivars were resistant to race 1, 2 prevalent in Fars and Isfahan provinces. Some cultivars from Japan and China like Golden Crispy and Ogon no 9 found to have low degree of tolerance to race 1,2. The inoculum potential of the races was important in cultivars reaction to races. Some cultivars were resistant or tolerant at low inoculum while becomes susceptible at higher levels.