Effect of Citral, Methyl anthranate and Nerol as fractions of citrus essential oils for controlling Cercospora and Alternaria leaf spot diseases of sugar beet under field condition was evaluated In laboratory experiments, results indicated completely reduction in linear growth of A. tenuis and C. beticola which were obtained with Citral, Methyl anthranate and Nerol at concentration of 5.0 ml/l. In field trials , results indicated that the most effective treatments was Citral, Methyl anthranate and Nerol at 5.0 ml/l. which reduced the Alternaria leaf spot severity more than 78.3 and 80.0 % respectively. Results showed that Citral, Methyl anthranate and Nerol at 5.0 ml/l. and fungicides (Ridomyl at 2 g/l) reduced the Cercospora leaf spot severity more than 67.5 and 78.1% respectively. The highest increase in sugar beet yield was obtained with Citral and Methyl anthranate at 5.0 ml/l. which increase the sugar beet yield more than 11.5 and 10.5 % respectively. Citral at concentration of 5.0 ml/l. increased the total soluble solids ( TSS) of sugar beet yield by 6.7% .While, slightly increase TSS was obtained with Citral at 2.5 ml/l., Methyl anthranate and Nerol at 5.0 ml/l. for each treatment. It could be suggested that constituents of essential oils may be used as eco-friendly natural compounds for controlling Cercospora and Alternaria leaf spot diseases of sugar beet plants under field conditions. |
