Pests and diseases Pests Cardamom Thrips (Sciothrips cardamom' Rank)
- This is a very serious pest occurring in cardamom. It attacks the flower buds and tender capsules which are punctured and on maturation, then scabby warts and corky outgrowths appear on the capsules.
- For the control of the pest, spray the crop with 0.025% Quinalphos or Monocrotophos (0.05%) or Phosalone (0.05%) alternatively during the months of March-September at monthly intervals.
Black hairy caterpillar (Eupterote canerica, E. cardomomi. E. fabia, Lenodera vittata and E. testacea)
- The caterpillars eat up the leaves and completely defoliate the clumps, resulting in the shrivelling up of the pseudo-stem, retardation of growth and reduction in yield.
- This pest can be controlled by dusting with 2% Methyl parathion dust or spraying Quinalphos (0.05%). In addition, the collection of the hairy caterpillars, which are found in large numbers, and destroying them, is recommended. Aponteles tabrobanac has been reported to parasitize caterpillars of Attacus atlas and E.fabia
- Shoot/panicle and capsule borer (Conogethes punctiferalis; Thamurgides cardamomi)
- The grubs bore into the stem and also into the fruit capsules. The infected plants are cut and removed. Spraying the crop with 0.075% Monocrotophos or Quinalphos (0.03%) is effective in controlling shoot and capsule borer. Eriborus trocharteratus and Xanthopinpla australis are the bio-control agents of this pest.
Shoot fly (Formosina flavipes)
- Spraying Quinalphos (0.03%) or Phosalone (0.05%) or Mono¬crotophos (0.05%) will control the pest.
Mites
- The infested plants show the symptoms like the drying up of leaves, which also becomes yellow in colour. To control this pest, Parathion (0.2%) may be sprayed.
White fly (Kanagarajiella cardamom')
- Both the adult and nymphs suck the sap from the leaves and the leaves become yellow.
- The nymphs are seen on the lower surface of the leaves.
- To control the pest, yellow sticky traps (rectangular metal/ polythene sheets painted yellow and coated with a sticky substance such as castor oil or grease) are fixed vertically inside the cardamom plantation at 3'-5' height from the ground level.
- The simultaneous spraying of neem oil @ 0.3 to 0.5% (mix 300-500 ml each of neem oil and Triton or Sandovit in 100 litres of water) should be carried out at 20-25 days, interval.
Root grub (Basilepta fulvicorne)
- Occasionally this pest also causes damage to the crop and this can be controlled by soil application of Carbofuran @ 10 kg/ha during July and December.
- The fungus Metarhizium sp. has been found to infest the root grubs.
Nematodes
- The root-knot nematode, Meloidogyne incognita and Radopholus similes, infest cardamom plantations. The suggested control measure for this is the application of Phorate 10 G @ 30g/clump twice, during May-June and again in September. Verticillium chlamydosporium and ten isolates of fluorescent pseudomonas and VAM are the biocontrol agents of the nematodes.
- The bonnet monkey (Macaqua radiata) is reported to damage the cardamom suckers. The soft scale Coccus hespiridum and its parasite (Coccophagus ceroplastae), the leaf beetle (Lema fulyimana) and Breyipalpus californicus have also been reported as pests.
Diseases
- The major diseases that attack cardamom are the `Icatte' disease, leaf disease, rhizome-rot, damping-off, leaf rust and nursery leaf-rot.
Katte or Marble disease
- This is a virus disease and is transmitted by the banana aphid Pentalonia nigroneryosa f. caladii.
- The disease is characterised by general chlorisis, followed by slender interrupted streaks on the leaves.
- The subterranean rhizomes will be shrivelled leading to a reduction in size and productivity of the clump.
- The vector may be controlled by regular spraying with Parathion (0.2%) or with systemic insecticides like Metasystox, Rogor or Dimecron at 0.5% concentration or Bioneem (0.5%) and Margolin (1%).
- The affected plants have to be uprooted with the rhizomes intact and destroyed three days after spraying.
- Disease-free planting materials should be used for planting. It is also recommended that phytosanitation measures are adopted.
- The green lacewing (Chrysoperla cornea) is highly predaceous to the aphid. The sources of resistance/tolerance for this disease are NKE 3 and NKE 73.
Leaf disease
- The affected tissue becomes dry and brown and shredded into thin
- strips. The leaves dry up and cause the eventual death of the plants. Spraying 1% Bordeaux mixture will control the disease.
Rhizome-rot
- This is caused by Pythium sp. and Rhizoctonia solani. The leaves
- become pale yellow and it causes the premature death of older leaves.
- The base of the shoots get brittle and break away.
- The affected plants have to be removed and destroyed.
- Drenching the soil with 1% Bordeuax mixture will control this disease.
- The variety RR-1 released from the Cardamom Research Station, Appangala, is resistant to this disease.
- Trichoderma harzianum using coffee husk as carrier and Paecilomyces lilacinus are the biocontrol agents of this disease.
Damping off/seedling rot/clump rot (Pythium vexans; Rhizoctonia solani)
- This disease causes heavy mortality of seedlings in the nursery. To control this disease, nurseries have to be provided with proper drainage and drenching with Bordeaux mixture or Copper oxychloride (0.2%) during June, August and October has to be done.
- Nursery leaf-rot (Coniothrium sp. and Phyllosticta elettariae)
- On the leaves of the plants in the nursery, small water-soaked spots first appear, gradually extending into large areas in which the chlorophyll is completely destroyed.
- The affected tissues become flaccid and shrink up to the mid-rib.
- This may be controlled by spraying 0.2% Captafol or 1% Bordeaux mixture at 15-day intervals during the monsoon.
- Bacterial wilt and nematodes are the other nursery diseases.
- The application of Streptocycline (200 ppm) against wilt during June, and Ablicarb granules @ 1 g a.i/sq.m. against nematodes has been suggested.
Capsule rot (Azhukal)
- The causal organism for this disease is Phytophthora meadii, phytophthora nicotianae var. nicotianae.
- The control measure suggested for this disease is spraying and soil drenching with BM (1%) or Copper oxychloride (0.2%) or Aliette (0.3%) during August and October.
Kokkekandu (Vein-clearing virus)
- This is a viral disease caused by the potty virus. The banana aphid is also the vector for this virus. This disease is characterised by vein clearing on leaves and the affected plants produce hook-like shoots.
- Leaf mottling, shredding, quick decline and the death of the clumps result in poor yield. For control, the same disease management practices as that of Katte are followed. The clone 893 is resistant to this disease. The other viral diseases are Cirke disease (mosaic), Nilgiri necrosis virus (NNV) and Forkey (reported from Sikkim)
Seed rot (Fusarium sp.)
- The rotting of cardamom seeds can be prevented by treating the seeds with Bavistin 2.5% or Captan (4 g/kg of seed).
Cropping
- The flowering starts in April-May and continues actively for about 3 to 4 months, i.e., till August-September.
- The inflorescence comes up from the base of the stems of the previous year's growth. In fact, flowering can be observed almost throughout the year. Due to this fact, the ripening of capsules is irregular, which necessitates several pickings.
- The fruiting period (i.e., from the opening of the flower to the ripening of the fruit) is nearly 3-4 months. As many as 75 inflorescences with a number of flowers in each are borne by a single plant.
|