In vitro and in vivo evaluation of different measures to control Ascochyta blight in chickpea

Ascochyta blight, an infection caused by Ascochyta rabiei is a destructive disease in many chickpea growing regions and it caused significant yield losses. To minimize the impact of Ascochyta blight, 5 fungicides viz., Aliette, Cabrio Top, Thiovit Jet, Cymoxanil and Difenoconazole, 5 plants extracts namely Azadirachta indica, Azadirachta azedarach, Datura stramonium, Chenopodium album and Allium sativum L. and two strains T-22 and E58 of bio-control agents (BCAs) Trichoderma viride and Aspergillus flavus were evaluated on the growth of A. rabiei under in vitro conditions by using the food poison technique. The colony growth of Ascochyta rabiei was inhibited at all concentrations of fungicides @ 0.07, 0.15, 0.21%, plants extracts @ 4, 6, 9% and bio-control agents @ 105, 106 and 107 conidia ml-1 respectively. Among all applied treatments, maximum inhibition colony growth of pathogen was recorded in the case of Aliette (83.4%), followed by Cabrio Top (74.3%), Azadirachta indica (50.3%) and Trichoderma viride (60.3%) at their high concentrations. Field trials showed that Aliette and Cabario Top significantly reduced the disease severity to 10 % and 24% respectively, followed by Azadirachta indica and Allium sativum which reduced the disease severity to 40% and 50% respectively. Bio-control agent Trichoderma viride proved less effective in controlling Ascochyta bight severity under field conditions. The present study showed that systemic and sulphur containing fungicides, plant extracts and bio-control agents (BCAs) have the potential to control Ascochyta blight in both in vitro and in vivo conditions