Effect of Aquatic Extracts of Five Plant Species in the Control of Alternaria Leaf Spot Disease on Faba Bean in Vitro

Abstract

 This research was conducted at the University of Idlib (2019- 2020).it studies The effect of aqueous extracts of five plant species in vitro, (Azedarach fruits, garlic cloves, eucalyptus leaves, thyme and rosemary, with three concentrations of each extract: 5%, 10% and 20%) on inhibiting the radial growth of Alternaria alternata that causes alternaria spotting disease on the Faba bean plant isolated from Infected Faba bean plants on PDA, and comparing the effect of these extracts with the fungicide (diphenoconazole + azoxystrobin) known commercially as Amstar Top.

The results showed that all the extracts of all concentrations caused a clear inhibition of the radial growth of the fungus in varying proportions, and there were clear significant differences among the extracts themselves and among the different concentrations within the same extract at a significant level of 0.01. The highest inhibition percentage of the pesticide Amstar was 100%, followed by the concentration of 20% of the extracts: Azedarach fruits, garlic cloves, rosemary leaves, eucalyptus leaves, and thyme leaves with inhibition rates of 68.55%, 64.22%, 60.83%, 57.56%, and 53.89% respectively.

The inhibitory concentration of 50% of the tested strains fungi (IC50) of the extracts was: 8.13%, 9.33%, 12.3%, 14.79%, 17.38%. for each of Azedarach fruits, garlic cloves, rosemary leaves, eucalyptus, and thyme respectively.