Major diseases of Cardamom are:-
1.Damping off / rhizome rot/clamp rot – Pythium vexans, Fusarium oxysporum, Rhizoctonia solani, Phytophthora
- 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.
- Destruction of diseased clumps.
- Providing proper drainage
- Changing the nursery site
- Drenching the nursery beds with Copper oxychloride 0.25% or Bordeaux mixture 0.5%, before 15 days of sowing.
- Soil drenching with B.M 1% (or) PCNB 1.0%
2.Azhukal disease/capsule rot/fruit rot – Phytophthora parasitica car. nicotianae/ Phytophthora palmivora
- Symptoms can appear on the 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 sheath.
- 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 off in 3-6 days leaving the small fruit stalk. The tip of inflorescence also rot.
- Removal and burning of infected plants.
- Avoid moving of rhizomes from diseased areas to healthy area for planting
- Provide proper drainage
- Three sprays with Bordeaux mixture 1% in May, June, July
- Soil drench with Bordeaux mixture 1 % (or) Copper oxychloride 0.25%
3.Cardamom mosaic virus (CDMV)
- General chlorosis of young leaves – parallel streaks of pale green tissues running along the veins from midrib to the margins.
- Leaf sheath also shows stitch stripes.
- In the advanced stage, the whole plant shows the mosaic symptom.
- Rhizome shrivels and plants dies. If young clumps are attached they die before flowering.
- Vector: Pentalonia nigronervosa
- Collection and removal of infected clumps along with rhizomes and burning.
- Raising of the nursery in diseases free areas.
- Spray with dimethoate (or) Methyl dematan (or) Phosphomidon to kill the vector.
4.Chenthal disease/leaf blight – Colletotrichum gloeosporioides
- Elongated, water soaked lesions of varying size appear on the upper surface of the leaf.
- The spots become brown to dark with a pale yellow hole. Leaves wither and pseudo stem wilts.
- New shoots which develop are reduced in size. Flowers fail to develop.
- The inflorescence dries up starting from tip downwards. The affected garden shows burnt appearance.
- Removal and destruction of affected leaves
- Three sprays with carbendazim 0.1% (or) Mancozab 0.2% (or) copper oxychloride 0.25% at 30 days interval.
- TamilNadu Agritech Portal