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P. Sreerama Kumar ¹, S. P. Singh ¹, C. P. Anuroop ¹

Affiliations
1 Project Directorate of Biological Control (ICAR), P. B. No. 2491, H.A. Farm Post, Hebbal, Bellary Road, Bangalore 560 024, Karnataka, IN

Abstract

The hyphomycetous fungus, Sporothrix fungorum de Hoog&de Vries was discovered affecting the coconut eriophyid mite, Aceria gllerreronis Keifer in Karnataka and Tamil Nadu in India during 1999-2000 in up to 15 per cent of coconut samples. At 2xlOs, 2xl0· and 2xl07 conidia per ml the fungus could bring' about 47.03, 92.75 and 98.29 per cent mortalities, respectively, 96h after inoculation. It was able to grow and conidiate profusely on potato dextrose agar (PDA) as well as Sabouraud dextrose agar (SDA). The diameter of the colony increased significantly between 10 and 21 days of inoculation in both the media, reaching up to 35.83 and 36.00 mm on PDA and SDA, respectively. Among three different liquid media, viz., potato dextrose broth (PDB), Sabouraud dextrose broth (SDB) and an enrichment medium (EM), EM was the best in terms of wet and dry weights (per 100 ml) as well as conidia production in both stationary (6450.3 mg, 1602.3 mg and 71.7 x 106 / ml) and shake cultures (13416.7 mg, 3402.7 mg and 83.0 x 107 / mI). The present report gives new details about S. fungorum as well as its association with the coconut mite.

Keywords

Aceria gllerrerollis, Biological Control, Coconut, Eriophyid Mite, Sporothrix fungorum.

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R. D. Prasad ¹, R. Rangeshwaran ¹, C. P. Anuroop ¹, P. R. Phanikumar ¹

Affiliations
1 Project Directorate of Biological Control (ICAR), P. B. No. 2491, H. A. Farm Post, Hebbal, Bangalore 560 024, Karnataka, IN

Abstract

The conidia and chlamydospores of Trichoderma harzianum produced by solid state and liquid fermentation, respectively, were formulated as powder and tested for their comparative bioefficacy and shelf life. Both the propagules did not differ significantly in reducing ischolar_main rot incidence in chickpea caused by Rhizoctonia solani. Conidial formulation retained optimum amount of viable propagules (>10⁶ cfu/g) even after 180 days of storage at room temperature but in chlamydospore formulation, viable propagules reduced to less than 10⁶ by 150 days.

Keywords

Bioefficacy, Chlamydospores, Conidia, Formulation, Shelf Life, Trichoderma harzianum.

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R. Rangeshwaran ¹, R. D. Prasad ¹, C. P. Anuroop ¹

Affiliations
1 Project Directorate of Biological Control (lCAR) Post Bag No.2491, H. A. Farm Post, Bellary Road Bangalore 560024, Karnataka, IN

Abstract

Talc based formulations of two antagonistic bacteria viz., Pseudomonas putida (PDBCAB 19) and P. fluorescens (PDBCAB 2) were evaluated against natural incidences of wilt and wet ischolar_main-rot of chickpea. Observations on rhizoclonia ischolar_main-rot incidence indicated that the disease was prevalent up to 60 days of plant growth whereas fusarial wilt was observed from 60 days. At 30th day. highest ischolar_main-rot incidence (10.8%) was observed in pathogen control plots and minimum was in fungicide treated plots (3.1 %). P. fluorescens (PDBCAB 2) treated plots also exhibited low ischolar_main-rot (4.4%). However, at day 60 lowest ischolar_main-rot incidence (5%) was recorded in P. fluorescens (PDBCAB 2) treated plots and highest ischolar_main-rot incidence (13.9%) was observed in pathogen control. Low ischolar_main-rot incidence (5.8%) was also noticed in P. putida (PDBCAB 19) treated plots. Fusarium wilt was lowest (3.3%) in P. putida (PDBCAB 19) treated and highest (13.3 %) in control plots at day 90. Combination of both P. fluorescens (PDBCAB 2) and P. putida (PDBCAB 19) exhibited suppression of ischolar_main-rot and wilt incidences by 5.8 and 7.5 per cent, respectively. Highest plant stand and seed yield was observed in P. fluorescens (PDBCAB 2) treated plots. There were no significant differences in the shoot and ischolar_main lengths among bioagent treatments, however, vigour index was highest in plots treated with a combination of P. fluorescens (PDBCAB 2) and P. putida (PDBCAB 19).

Keywords

Antagonistic Bacteria, Chickpea, Root-Rot, Wilt.

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