Cardamom thrips

CARDAMOM ELETTARIA cardamomi Maton the ``Queen of spices'' is indigenous to the evergreen forest of western Ghats in South India.

Till recently India was the main crop is prone to a number of pests of which cardamom thrips Sciothrips cardamomi Ramk cause more than 47 per cent of yield loss. The greyish brown adult insects lay minute kidney shaped eggs on panicle, leaf sheath and flowers which hatch into nymphs in 12 days. The thrips lacerate surface of the tissues with mandibles and suck the exuding plant sap.

Affected capsules appear malformed, rusty, shriveled and some time with gaping slits. Such capsules are inferior in aroma, have less number of seeds, seeds are under-developed may not germinate and fetch low price in the market. The population is maximum in summer (Feb. to May), minimum in rainy period (June to July) and low in August to December. The following Integrated Pest Management Practices (IPM) may be followed for effective control.

- Remove all the dry drooping leaves, leaf sheath and old panicles immediately before commencement of first application of insecticide.

- Remove alternative host plants such as Panicum longipes, Amomum sp, Colacasia sp and Alacasia sp.

- Maintain plant density with wider spacing of 2.5 x 2.5m.

- Regulate the shades.

- Apply any one of the following insecticides in summer with 30 days interval - fenthion 500 ml, profenofos 500 ml, phasalone 1000 ml and monocrotophos 1000 ml/ ha using high volume sprayer.

- During peak flowering periods, insecticide which is less toxic to honey bees (Phasalone) may be sprayed.

- If water scarcity is felt during summer any of the following dust formulations may be applied such as quinalphos 25 kg, phasalone 25 kg, phenthoate 25 kg and methylparathion 25 kg.

D. Rajabaskar, R.S.Suresh Kumar & A. Regupathy

TNAU, Coimbatore 624 003

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