B. K. Sharma ¹

Affiliations
1 Himachal Pradesh Krishi Vishwavidyala, Regional Research Station, Dhaulakuan 173001, Himachal Pradesh, IN

Abstract

In dual cultures, biocontrol agents viz., Trichoderma harzianum, T. viride , Gliocladium virens, Absidia cylindrospora and plant extracts viz., Agave americana, Azadirachta indica, Cassia fistula, Eucalyptus terticornis, and Vitex negundo were evaluated against causa] fungi of yellows and rhizome rot of ginger. Trichoderma harzianum, T. viride, Azadirachta indica and Agave americana were most effective in reducing mycelial growth of Fusarium oxysporum f sp. zingiberi Trujillo and Pythium aphanidermatum (Eds.) Fitz causing yellows and rhizome rot of ginger, respectively.

Keywords

Antifungal Properties, Biocontrol Agents, Ginger, Plant Leaf Extracts, Rhizome Rot.

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B. K. Sharma ¹

Affiliations
1 HPKV, Regional Research Station, Dhaulakuan, Distt. Sirmour (H.P.) 173001, IN

Abstract

The Antagonistic fungi, viz., Trichoderma harzianum, T. viride, Gliocladium virens, Absidia cylindrospora Alternaria alternata and Fusarium solalli were evaluated against Sclerotinia sclerotiorum causing chickpea stem rot. T.harzianum and A.cylindropora were most effective in inhibiting the mycelial growth in dual cultures. Inhibitory activity of autoclaved culture filtrates was much less as compared to filter-sterilized culture filtrates. Culture filtrates of T.harzianum, G. virens and T. viride were particularly effective in inhibiting sclerotial germination. In pot culture experiments, wheat bran-saw-dust-tap water (1:1:6;W/W/v) mixture was most effective in reducing seedling mortality. Application of antagonists in Sclerotinia - sick plots reduced the disease incidence and increased yield over control. T.harzianum was most effective followed by G. virens and T. viride.

Keywords

Sclerotinia sclerotiorum, Trichoderma harzianum, Stem Rot, Chickpea, Antagonist.

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B. K. Sharma ¹, B. M. Singh ¹, S. K. Sugha ¹

Affiliations
1 H.P. Krishi Vishvavidyalaya, Palampur - 176062, IN

Abstract

Integrated effect of biocides and fungicides on sclerotlal germination of Sclerotinia seleratiorum (Lib.) was studied under in vitro conditions. MBC and Bayleton reduced sclerotial germination with an increase in dipping duration at higher concentration. At 100 μg/ml, ten and twenty min. dipping in MBC and Bayleton respectively, caused complete inhibition of sclerotlal germination. Complete kill of sclerotia was obtained with MBC at 5 μg/ml with 10 min. dip and 4 × 10⁸ spores/ml of Trichoderma harzianum Rifai whereas 15 min. dip was required for the same effect with Bayleton. A combination of presoaking, high temperature, treatment with MBC and Bayleton and three biocontrol agents significantly reduced sclerotlal viability. Complete inhibition or sclerotial germination was obtained with T. harzianum and Gliocladium roseum with the highest spore density(4 × 10⁸ spores/ml) at 50 and 55 °C.

Keywords

Scterotinia sclerotiorum, Trichoderma harzianum, Gliocladium roseum, MBC, Bayleton.

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B. K. Sharma ¹, B. M. Singh ¹

Affiliations
1 H.P. Krishi Vishvavidayalaya, Palampur-176 062 (H.P.), IN

Abstract

White rot of pea caused by Sclerotinia sclerotiorum (Lib.) is a serious menace in Kangra valley of Himachal Pradesh. The pathogen is polyphagous and soil borne, therefore, difficult to control through fungicides and host resistance. Because of the limitations in the use of fungicides as well as to minimize the pollution hazards, use of fungal antagonists as biocontrol agents against S. sclerotiorum was deemed very important. Keeping in view these aspects, present investigations were, undertaken.

Keywords

Sclerotinia sclerotiorum, Trichoderma harzianum, T. viride, Gliocladium roseum, Epicoccum nigrum, Pea.

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