Antifungal Activity of Some Fungicide Alternatives on the Main Postharvest Pathogen of Tomato Fruits in Egypt

Tomatoes crop and yield is suffered every year due to number of pathogenic diseases. Alternaria rot considered as the most common diseases of tomato fruits and causes heavy losses in quality of the fruits, thus rendering large quantity of tomato fruits unfit for consumption. Several essential oils and minerals were evaluated for their efficacy as potential fungicides against Alternaria alternate. Potato dextrose agar plates were inoculated with a disc of the 7 days old culture of tested fungus after a period of growth the growth inhibition was measured. Showed an ethanol extract of essential oils at concentrate 100 µl/l of clove oil has had the ability to inhibit fungal growth rate of 73.11% also jojoba oil gave inhibition of fungal growth rate of 32.22% while concentration gave 50 µl/l inhibitions by 40% for clove oil. On the other hand, out of four evaluated minerals, metal salts tested showed K₂SO₄ at 0.24% resulted A. alternate in maximum inhibition of growth (64.4%) followed by MgSO₄ by 52.2%. Chitosan, as antifungal agent, was found affected on the linear growth of A. alternate pathogen. The largest effect on A. alternate by 62.22% was observed at 6mg/ml. The obtained results in this study showed the possibility of usage K₂SO₄ and clove oils or chitosan to control fruit rot caused by A. alternate.