Vol. 10, Issue 5 (2021)

Author(s):
Arunasri P, Padmodaya B, Prasanthi A, Naidu MVS, Tirumala Reddy S, Reddi Kumar M, Koteswara Rao SR and Ravindra Reddy B

Abstract:
Sclerotium rolfsii Sacc. is a major soil borne pathogen that causes stem rot of groundnut. Per cent incidence of stem rot will be influenced by soil health that include soil pH, electrical conductivity, organic carbon and which in turn influence soil microflora (fungi, actinomycetes and bacteria). Integrated Disease Management practices like combination of Indigenous Technology Knowledge inputs like Modified Panchagavya, Combination fungicide Hexaconazole 4%+Zineb 68% (Avtar), biocontrol agent Trichoderma asperellum GT₄ and organic amendment (Neem cake) were combined in the form of 14 treatments including inoculated control and un-inoculated control. In the present investigation impact of these soil health aspects on disease incidence of stem rot of groundnut was studied. With the soil pH 7.4 (at 45 DAS) and 7.2 (at the time of harvest) per cent disease incidence of stem rot was least (9.08% and 14.13%) in treatment T₁₂ that includes seed treatment with Hexaconazole 4%+Zineb 68%(Avtar),seed treatment with T. asperellum GT₄ and neem cake application@500kg/ha. With the highest electrical conductivity (0.79) and organic carbon (0.87), disease incidence of stem rot was least (9.08% and 14.13%)in treatment T₁₂. Soil microflora responded differently to these treatments and edaphic factors. Soil fungal population increased even upto harvest and were highest in T₉ (94 ×10⁴ cfu/g soil) with mean of 88 ×10⁴ cfu/g soil in treatment T₉. Actinomycetes were highest (72.22×10⁵ cfu/g soil) in treatment T₈ where as bacteria were highest (72.56 ×10⁶ cfu/g soil) in treatment (T₁₂). Overall mean soil microflora were highest in treatment T₁₂ (63.37 cfu) and thus neem cake was found to influence disease incidence and soil health.