SPICES & CONDIMENTS : Nutmeg

Introduction :

Nutmeg is native of Molucces Island (Indonesia) and was introduced to India towards the end of the 18^th century and is grown now in certain pockets of Kerala, Tamil Nadu, and Karnataka. They are important to confectionery, culinary and pharmaceutical industries. Nutmeg and mace also yield 7 to 16 and 4 to 15% of oil respectively. This oil is used for flavouring food products and liquors and also in perfumery industries. Oleoresin of nutmeg and mace is used almost entirely in the flavouring of processed foods. The nutmeg butter prepared by the expression of fat from the ground, cooked nutmeg is mostly used to impart spicy odour to the perfumes. The pericarp is used for making jams, jellies and pickles.

Botanical name of nutmeg is Myristica fragrans Houtt which belongs to family Myristicaceae. Nutmeg is a densely foliated evergreen tree growing to a height of 20m and above. The fruit is a fleshy drupe, spherical or slightly ovoid in shape and pale yellow in colour with a longitudinal groove in the centre.

Climate and Soil :

Nutmeg thrives well in warm humid conditions in locations with an annual rainfall of 150cm and more. It grows well from sea level upto about 1300m above MSL. Areas with soils of clay loam, sandy loam and red lateritic are ideal for its growth. Both dry climate and water logged conditions are not good for nutmeg. The soil and climate prevailing in the hill slopes of Western Ghats and Eastern Ghats (from 700 to 1300m) are ideally suited to grow nutmeg.

Varieties :

There is no named variety of nutmegs in India.

Propagation and nursery techniques :

Nutmeg trees are usually propagated through seed. Large sized tree burst fruits from high yielding trees are harvested or collected as and when they fall down. The fleshy rind of the fruit as well as the mace covering the seed is removed before sowing. The seeds should be sown in specially prepared nursery beds immediately after collection. If there is delay in sowing, the seeds may be kept in trays filled with moist sand or stored in ploybags or moss, which keep them viable for 15 days.

Regular watering is necessary for good germination. The germination may commence from about the 30^th day and lasts upto 90 days after sowing. About 20 days old sprouts are transplanted to polythene bags containing a mixture of good soil, sand and well decomposed cowdung (3:3:1). About 18 to 24 months old seedlings are used for transplanting in the field. Air layering, inarching and budding have also been attempted with varying degree of success, but the epicotyl grafting technique developed by NRCS, Calicur is found to be promising now.

Planting :

Seedlings are transplanted in the main field when they are 12 to 18 months old. Recommended spacing is 8 x 8m. Pits of 60cm cube are dug and filled with compost and topsoil. Seedlings are planted carefully in the centre of the pits during rainy seasons. Young plants are provided with artificial shade and irrigated during summer months. The basins are mulched with locally available trashes. As nutmeg requires light shade especially at early stage, fast growing shade plants like Erythrina indicia, Elithosperma or Gliricidia maculate or bananas are planted in between them a few months prior to planting. As nutmeg plants grow, these shade plants may be thinned out. Through not essential, irrigation is advantageous to grown up trees for getting better yield.

Nutmeg can be advantageously grown mixed with coconut and arecanut. When coconut is planted at a spacing of not less than 8 x 8m one plantations raised with a spacing of 2.7m x 2.7m, nutmeg can be planted at every third row of arecanut so that within the square formed by four nutmeg plants there will be nine arecanut seedlings. In coffee based mixed system also, nutmeg can be planted at a spacing of 7-8m.

Manures and fertilisers:

Nutmeg requires heavy manuring for proper growth and yield. Farm yard manure or compost at the rate of 10kg per plant may be applied during the first year of planting. The quantity should be increased every year so that a well-grown tree of about fifteen years and above may receive 50kg organic manure. During the first year, fertilizers to supply 20g nitrogen, 18g phosphorus and 50g potash are applied per plant. The fertilizer doses may be increased gradually every year till a well grown tree of fifteen years or more receives about 500g nitrogen, 250g Phosphorus and 1000g potash annually.

The fertilizers are applied in two equal split doses, first in May-June along with organic manure and the other in September-October. Shallow trench is dug around each tree at a radius of 1 to 1.5m away from the trunk for applying manures and fertilizers and covered after application of manures. As nutmeg has a very shallow root system, trenches should not be deep and no intercultivation is usually done very close to the trunk. However weeding is done periodically.

Harvesting :

Seedling trees start bearing in 7 to 8 years while grafts start bearing in 4 to 5 years. They attain full bearing stage after 15 to 20 years and may yield upto 60 years. Nutmeg trees flower throughout the year with a peak in certain months. Hence, though fruits are seen throughout the year, the peak season of harvest is from June to August. The fruits take 9 months from flowering to harvest. When the fleshy rind of the nut splits open, the fruits are fully ripe for picking. They are either plucked from the tree or are allowed to drop on to the ground and then collected. After removal of the outer fleshy rind, mace is detached from the seed shell by hand and flattened out. It is then allowed to dry slowly in the sun for ten to fifteen days. During drying the mace gradually becomes brittle and horny and attains a yellowish brown colour.

The seeds are dried separately for 4 to 8 weeks either in the sun or in artificial heat until the kernel rattles inside the shell, which is then broken open with a wooden mallet, and the kernel is taken out. The fleshy pericarp can be used for making pickles, jams and jellies.

Yield :

Individual nutmeg fruit weights on an average 60g of which the seed weighs 6 to 7g, mace 3 to 4g and the rest pericarp. A fully-grown tree under normal conditions may produce on an average 2,000 to 3,000 fruits per year. On the assumption that about 65% of the trees in a garden are female and are optimum yields, about 800 kg nutmeg and 100kg mace can be expected per hectare.

Plant protection :

Disease	Symptoms	Control measure
Die back (Diplodianatalensis)	Drying up of mature and immature branches from tip downwards.	Remove the infected branches; smear Bordeaux paste in the cut end of the branches.
Thread blight (Marasmius sp.)	Blighting of the affected stems or leaves	Spray 1.0-% Bordeaux mixture.
Fruit rot (Diplodia natalensis and phytophthora sp.)	Splitting of immature fruits and subsequent rotting of mace.	Spray 1.0-% Bordeaux mixture when the fruits are half-mature.