Management of Late Leaf Spot of Groundnut by Different Fungicides and Their Impact on Yield

In vitro experiments were carried out with Phaeoisariopsis personata isolate to determine its sensitivity/tolerance to different fungicides viz., Tebuconazole (0.05%), Tebuconazole (0.10%), Tebuconazole (0.15%), Tebuconazole (0.20%), Tebuconazole (0.40%), Folicur (0.10%) and Mancozeb (0.30%) using poisoned food technique both in solid and liquid medium. In the solid medium method, visual observation was taken 20 days after inoculation of the pathogen. There was no significant difference among the different fungicides in their efficacy against P. personata, compared to control. In case of liquid medium the observations were taken after 25 days of inoculation and the results are presented. There was significant difference between the fungicides in per cent inhibition against the mycelial growth of the pathogen, P. personata. Among all the fungicides, Tebuconazole 0.4% (87.97%t) showed maximum inhibition followed by Tebuconazole 0.2% (85.24%) and Tebuconazole 0.15% (83.50%), among these Tebuconazole 0.15% was found to be optimum. Application of fungicidal sprays influenced the development of Cercospora leaf spot and reduced its intensity. Among these applications of different fungicides, Tebuconazole (0.15%) gave best result and reduced the disease intensity to 52.42%. Area under disease progress curve (AUDPC) greatly varied among different fungicidal treatments and showed significant difference in yield data. Impact of fungicides used for disease control was apparent on yield per plot. Tebuconazole (0.15%) gave best result and increased yield up to 67% as compared to 39% increase by Tebuconazole (0.10 %).