Disease management strategies for Ascochyta blight of chickpea

Abstract

Management of chickpea ascochyta blight is a difficult task that requires ongoing attention and utilization of all possible techniques. Starting with clean seed of a resistant cultivar is critical, but even with this sound foundation, fungicide application is often necessary. Optimizing fungicide application strategies in chickpea is essential to protect the crop while simultaneously keeping costs as low as possible. Field experiments showed that early application of fungicide is crucial, and often additional applications were necessary for effective disease management. Of the product sequences tested, those including two strobilurin applications and two other applications during the season gave superior disease control in several cases, but this did not always confer higher yields. Nozzle type had no effect on disease development or yield in any of the field site-years. Similarly in the laboratory study, nozzle types had no effect on the amount of spray coverage or the degree of spray penetration into the crop canopy. A similar laboratory study comparing carrier volumes showed that using a higher carrier volume (>100 L ha-1) improves penetration of a fern leaf-type canopy, but offered no benefit in a unifoliate canopy. In the field, increasing carrier volume did not improve disease control when disease pressure was low to moderate. In some cases under high disease pressure, higher carrier volumes were important for achieving disease control.