Evaluation of Different Fungicides against Colletotrichum graminicola, the Cause of Red Leaf Spot of Sorghum

Abstract

| Sorghum (Sorghum bicolor L. Moench) is a very important cereal crop for human beings and livestock. It is subjected to many diseases in Pakistan like fungal, bacterial, and viral among which the fungal diseases are the most destructive. Colletotrichum graminicola is the causal organism of red leaf spot of sorghum which causes heavy losses to the sorghum crop cultivated in different areas of Pakistan. It produces black anthracnose spots on all the above ground parts especially leaves. In the present study, four fungicides (Aliette, Cabrio Top, Nativo, and Melody Duo) were evaluated against C. graminicola under in-vitro and in-vivo conditions. The poisoned food technique was used for in vitro trials with three concentrations (150 ppm, 200 ppm, and 250 ppm). The most effective concentration of fungicides from laboratory experiment was used in field conditions against red leaf spot of sorghum. Results showed that Cabrio Top was the most effective fungicide by showing 88% fungal inhibition while Native also exhibited good results by showing 78.1% fungal inhibition. The remaining 2 fungicides Melody Duo and Aliette were least effective by showing 48.2% and 37.5% fungal inhibition, respectively. In vivo experiment from all four fungicides, Cabrio Top and Nativo showed best results by controlling 74.57% and 71.52%, respectively disease over control while Melody Duo and Aliette were least effective by controlling 65.31% and 60.08% disease over control. It may be concluded that the Cabrio Top at 250 ppm concentration is the best to manage red leaf spot disease severity under field conditions.