Informatics Publishing Limited

A. K. Vijayan ¹, Joseph Thomas ¹, K. Dhanapal ¹, R. Naidu ¹

Affiliations
1 Indian Cardamom Research Institute, Myladumpara, Kailasanadu, Idukki, Kerala - 685 553, IN

Abstract

Small cardamom (Elettaria cardamomum Maton), ... the Queen of Spices is au important spice crop cultivated on a large scale in the Western ghats of South India. Rhizome rot is a major disease caused by Rhizoctonia solani Kuhn in cardamom plantations. The disease occurs in a severe form during monsoon and results in heavy crop losses. In the present study, exotic and native isolates of Trichoderma viride Pers. Fr. and T.harzianum Rifai were tested against the pathogen under in vitro conditions. These isolates were further evaluated in disease-prone areas in the field. Results showed that all the isolates tested showed antagonistic activity through hyphal coiling, penetration and lysis of the hyphae of the pathogen besides inducing growth inhibition of the laller. Among the nine isolates tested in the field, eight were found effective in controlling the disease incidence. An exotic isolate of T. harzianum and a native isolate of T. viride were found to be most effective, the reduction in disease incidence being upto 52 to 69 per cent.

Keywords

Trichoderma viride, Trichoderma harzianum, Biocontrol, Rhizoctonia solani, Cardamom.

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Joseph Thomas ¹, R. Suseela Bhai ¹, A. K. Vijayan ¹, R. Naidu ¹

Affiliations
1 Indian Cardamom Research Institute, Myladumpara, Kailasanad - 685553, IN

Abstract

The small cardamom (Elettaria cardamomum Maton) is severely affected by 'Azhukal' (capsule rot) and rhizome rot diseases caused by Phytophthora meadii McRae, Pythium vexans de Bary and Rhizoctonia solani Kuhn respectively. In an attempt to control these diseases through non-chemical methods, antagonistic fungi and bacteria were tested as bio-control agents against these rot pathogens. The common antagonists such as Trichoderma viride Pers.fr, T. harsianum Rifai, Laetisaria arvalis Burdsall and Bacillus subtilis (Ehrenburg Cohn) were tested under in vitro, pot culture and field conditions to evaluate their efficacy in suppressing the pathogens and minimising disease incidence. All the antagonists tested in vitro interacted with the pathogens by growth inhibition, anastamoses and hyphal lysis. Pot culture studies on the effect of these antagonists on pathogens showed varying degrees of disease reduction. Application of antagonists in Phytophthora-sick soils reduced soil disease potential index and percentage disease incidence. The potentiality or these biocontrol agents in monitoring rot diseases of small cardamom is discussed in this paper.

Keywords

Cardamom, Trichoderma, Azhukal Disease, Laetisatia, Phytophthora, Antagonist.

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