Diseases of Cardamom
Damping off / rhizome rot / clamp rot (Pythium vexans, Fusarium oxyoporum, Rhizoctonia solani)
Infected leaves become pale, yellow and ultimately the young leaves die. Older leaves die prematurely and new shoots that arise are weak, decay and the rhizomes rot at the base of the stem. The diseased shoot can be pulled out easily. The disease can be spoiled stem long distance by the presence of fallen shoots.
ManagementDestruction of diseased clumps. Providing proper drainage Changing the nursery site
Azhukal disease / capsule rot / fruit rot – ( Phytoplithora parasitica car. Nicotincanae, Phytophthora palmivora, P.meadii, Pythium vexans)
Symptoms can appear on tender and matured leaves. Large circular, irregular, water soaked spots with black colour appear on leaves. The exposed portion of the unopened leaves my rot. Grey patches of irregular spots with brown margin are formed at the base of the leaf sleath. The basal portion rots and the pseudo stem break away at the collar region. The infection spreads to the underground plants and the rhizomes become rots. Small light brown lesions appear in the green tender fruits which fall of in 3-6 days leaving the small fruit stalk. The tip of inflorescence also rot.
ManagementRemoval and burning of infected paricles and rhizomes. Avoid moving of rhizomes sum diseased areas to healthy area for planting Provide proper drainage
General chlorosis of young leaves – parallel streaks of pale green tissues running along the veins from midrib to the margins. Leaf sheath also shows stich stripes. In advanced stage the whole plant shows moxaic symptom clumps destoriates rapidly and plants are started. Rhizome shrivels and plants dies. If young clumps are attached they die before flowering.
ManagementCollection and removal of infected clumps along with rhizomes and burning. Raising of nursery in diseases free areas.
4. Chenthal disease / leaf blight (Colletotrichum gloeosporioides)
Elongated, water soaked lesions of varying size appear on the upper surface of the leaf. The spots becomes brown to dark with pale yellow hole. Leaves wither and pseudo stem wilts. New shoots which develop are reduced in size. Flowers fail to develop. The inflorescence dry up stating from tip downwards. The affected gardens shows burnt appearance.
ManagementRemoval and destruction of affected leaves
5. Nilgiris necrosis (Nilgiris necoros virus)
On leaves alternate light green to yellow patches or streaks appear parallel to the veins. A number of discontinues spocks appear on other areas of leaves. The virus spreads systemically in all the tillers. The leaves become small, stunted. The matme leaves tear off along the necrotic spots and shown shredded appearance leaves malformed.
ManagementUse healthy rhizomes for planting Rogue the infected plants.