Studies on Physical, Chemical and Amorphous Constituents of Associated Red and Black Soils: A Case Study in Hatti Schist Belt of North Karnataka.

Associated red and black soils of the transect from Hira region of Hatti schist belt were studied for their properties. Soils were moderately deep to deep, reddish brown (5YR 3/4) to dark black (10YR3/2), clay in texture. The pH ranged from 7.56 to 7.7, EC from 0.4 to 0.44dSm-1, low to medium in organic carbon, moderate in CEC (40.1 – 54.3 c mol (p+) kg-1). Free iron oxides ranges from (0.6-3.2%), Na2CO3 extractable free silicon ranges from (0.4-3.1%) and Na2CO3 extractable free aluminium ranges from (0.2 - 2.5%).

Pathogenicity Tests and Evaluation of Efficacy of Fungicides Against Rhizoctonia Bataticola, the Causal Agent of Dry Root Rot of Chickpea.

The pathogen was identified based on its mycelial and sclerotial characters and pathogenicity test was proved by soil inoculation method. Efficacy of two non systemic fungicides (copper oxychloride and captan), two systemic fungicides (hexaconazole and tebuconazole) and one antifungal antibiotic validamycin each at different concentrations were tested against Rhizoctonia bataticola, incitant of dry root rot of chickpea under in vitro conditions. The fungicides copper oxychloride, captan, hexaconazole and tebuconazole were found to be highly effective (100%) in inhibiting the mycelial growth of the highly virulent pathogen at all the concentrations tested.

Mycoparasitism of Trichoderma Spp. on Rhizoctonia Bataticola, the Causal Agent of Dry Root Rot of Chickpea.

Mode of parasitism between Trichoderma and Rhizoctonia bataticola was examined under a microscope. Formation of several loops and coiling around the hyphae of pathogen, forming a thick compact rope like structure followed by rupturing, twisting and leakage of hyphal protoplasm, air bubbling inside the cytoplasm, breaking of cytoplasmic continuity, aggregation of cytoplasm within cell leading to severe vacoulation were observed at later phase of interaction.