This study aimed to evaluate the effects of four antioxidants (Ascorbic acid, Citric acid, Oxalic acid and Salicylic acid) each with 3 concentrations (2.5, 5.0 and 10.0mM) on the linear growth and spore germination of F. oxysporum.
The obtained results revealed that, all the four antioxidants under study decreased the linear growth and spores germination of F. oxysporum with different degrees. Oxalic acid at concentration 10 mM completely inhibited mycelial growth of F. oxysporum followed by Salicylic acid at concentration of 10 mM was reducing the linear growth of F. oxysporum by 59.43%. While all antioxidants at concentration 5 and 10 mM completely inhibited spore germination of F. oxysporum.
The same antioxidants at the same concentrations were used to test their efficacy in reducing disease incidence and disease severity of cucumber Fusarium wilt disease. All antioxidants are used as seed soaking.
The obtained results showed that, in general, both disease incidence and disease severity of Fusarium wilt disease were reduced as a result of treatment by all antioxidants compared to the control. Percentage of disease incidence and disease severity was decreased by increasing the concentration of tested antioxidants from 2.5 up to 10mM. In all cases, Salicylic acid was the most effective antioxidants on disease development as it reduced the percentages of disease incidence and disease severity and increased the percentage of survival plants in addition Salicylic acid at 10 mM completely prevented the disease followed by Oxalic acid & Citric acid at 10 mM and reducing the disease severity by 95.00 and 91.33% respectively. On the other hand, Citric acid at 2.5 mM was the least effective concentration and reduced the disease severity by 76.33%. |
