Cardamom Pathology
The chapter discusses, at length, the cardamom pathology, with specific reference to the dreaded “Katte” disease, the causal pathogen and its control, also, minor diseases of cardamom are discussed. It discusses the disease symptoms, damage, and control m
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Cardamom Pathology
Abstract The chapter discusses, at length, the cardamom pathology, with specific reference to the dreaded “Katte” disease, the causal pathogen and its control, also, minor diseases of cardamom are discussed. It discusses the disease symptoms, damage, and control measures. It also discusses the role of biological control measures. Keywords “Katte” disease · Capsule rot · Rhizome disease · Disease management · Viral disease · Integrated disease management
Cardamom plant is affected by a number of pathogens of which some are fungi, others bacteria, and still others nematodes. These pathogens affect the plant in both nurseries and main plantations. To date, as many as 25 diseases caused by pathogens have been reported. On the basis of severity of damage, these diseases are categorized into major and minor. Considerable damage is caused by four major diseases in the plantations and two in the nurseries. Major diseases, such as rots, leaf blights, and nematode infestations, are often widespread and lead to crop losses, while minor diseases generally cause damage to the foliage. Unless properly managed, diseases can cause up to a 50% loss of the crop.
6.1 Major Diseases Capsule rot (locally referred to as Azhukal) and rhizome rot cause the most severe damage. Leaf blight and nematode infection lead to the weakening of plants and a consequent reduction in productivity. Table 6.1 lists the major diseases.
© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2020 K. P. Nair, The Geography of Cardamom (Elettaria cardamomum M.), https://doi.org/10.1007/978-3-030-54474-4_6
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6 Cardamom Pathology
126 Table 6.1 Major fungal and nematode diseases of cardamom Disease Capsule rot (“Azhukal”) Rhizome rot (clump rot) Leaf blight (“Chenthal”) Root knot nematode
Affected plant parts Capsules, leaves, panicles, young tillers Rhizomes, tillers, roots Leaves
Causal pathogen Phytophthora meadii, Phytophthora nicotianae var. nicotianae Pythium vexans, Rhizoctonia solani, Fusarium oxysporum Colletotrichum gloeosporioides
Roots, leaves
Meloidogyne incognita
6.1.1 Capsule Rot (“Azhukal” Disease) Capsule rot is locally known as Azhukal disease. (In the South Indian state of Kerala, “Azhukal” means “rotting” in Malayalam, the language spoken there.) Azhukal is the most severe fungal disease of cardamom. Menon et al. (1972) reported it for the first time in the cardamom plantations of Idukki district in Kerala State. 6.1.1.1 Geographic Distribution of the Disease Initially, symptoms of rotting are observed on the fruits or capsules, and that is the reason the disease has been named capsule rot. Subsequently, symptoms are observed in other plant parts. Azhukal is the major disease affecting cardamom, and it causes severe loss of productivity in the Idukki and Wayanad districts of Kerala State and in the Anamalai Hills of Tamil Nadu (Thomas et al. 1989). The disease appears following the onset of the southwest monsoon. Capsule rot is not observed in
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