Nutmeg is a perennial ever green spice tree and a native of Molluccas in East Indonesia. There is some evidence to suggest that the Roman priests may have burned nutmeg as a form of incense. It is also known to have been used as a prized and costly spice in medieval cuisine, used as flavorings, medicines, preserving agents and that were at the time highly valued in the European markets. Nutmeg is reported to have been introduced to Sri Lanka in the beginning of the 19th centaury but there are evidences that the crop had been brought here even before that by merchants who were traveling on the Silk Road.
Products and Uses
Nutmeg and mace are the main two products. Oils are extracted from both nutmeg and mace. Powdered nutmeg and mace is used in curry powders.
Nutmeg and mace are mainly used for culinary purposes to flavor curries and other food products, confectionaries and bakery products. It is also used in preparation of beverages and drinks. Nutmeg is used as an ingredient in Ayurvedeic and Chinese medicine.
Major Growing Areas
Nutmeg prefers cooler climates hence mid country areas of Sri Lanka are ideal for the growth of nutmeg. Total extent of Nutmeg in Sri Lanka is 924ha and from which 80% of the extent is in Kandy district. Other major growing areas are Kegalle and Matale districts.
In Sri Lanka no specific varieties have been identified. Mother trees are selected considering high yield (over10,000fruits/tree/yr), regular bearing habit, size of the nut (wet weight 10g /fruit) and heavy mace (wet weight 1g/fruit).
Soils and Climatic needs
Deep well drained loams, and sandy clay loams rich in organic matter are preferable. Soils with high water table or liable to water logging are unsuitable.
Rainfall – well distributed rain fall of 1,500-2500mm. is sufficient
Temperature – average annual temperature should be 20-30 C
Altitude – up to 1500m
Shade is essential during the first two years of growth. Thereafter exposure to light is beneficial. However cooler, humid micro climate is much preferred for establishment and fruit setting.
Persistent strong winds are harmful. Sheltered valleys and leeward slopes are best for growing cardamom.
Seeds are used for planting. Dark brown full sized seeds of matured fruits from selected mother plants are used for planting. Seeds have to be sown in nursery beds as soon as possible since the viability is lost within 8-10 days.
Seedlings are potted in poly bags filled with a mixture of equal parts of top soil, cow dung and sand. About 10g of rock phosphate are also added. Seedlings are kept under shade for about 6-8 months, then hardened and transplanted in the field. If large size plants are needed seedlings of 6-8 months of age are re-potted in bigger poly bags filled with same mixture and kept for another 9-12 months. Bigger plants establish well in the field.
For healthy growth of nursery seedlings, fertilizer solution (1kg urea, 0.5kg TSP, 0.75kgMOP dissolved in 100L of water) can be sprayed.
Spacing – 20’x20’(250 plants/ha.)
Planting is done with the on set of monsoon rains. Planting hole is 21/2’x21/2’ in size and is filled with a mixture of top soil and cattle manure. The collar of the plant has to be at the soil level and the care has to be given not to damage or bending the tap root during the planting. Soil around the plant has to be mulched adequately after the planting.
Temporary shade has to be provided to protect plants from direct sunlight. It is better if temporary shade trees have to be planted before 6-8 months of planting.
Removal of Male Plants
There are separate male and female trees in nutmeg but the sex cannot be identified from out side appearance. Only way for an average farmer to identify the sex of tree is after flowering. Generally 50% of the seedlings are males. Male trees do not set fruits but are essential for the pollination. Therefore after flowering male trees are removed marinating 1: 10 of male: female ratio. Vacancies are in-filled with new plants.
Recommended mixture - 625 kg / ha at the 10th year and after (density 250 plants/ha)
|Components of the mixture
||Parts by weight
||Nutrient in the mixture
|Rock phosphate ( 28 % P2O5)||2||8% P2O5|
|Muriate of potash (K2O)||3||25% K2O|
|Kieserite (24%MgO)||1/3||1% MgO|
Rate of fertilizer application:
|10 yr. onwards||1250||1250|
Terracing and Weeding
It is essential to bench terrace the base of the seedling particularly in sloping lands initially to a diameter about 0.5m. and thereafter widen as plant grows. An inward slope of the terrace will help to reduce the erosion of cut soil.
Weeds must be kept under check. Frequent slashing is recommended and slashed material must be applied to the base of the plant as mulch.
Diseases and Pests
There are no economically important disease and pest problems.
Harvesting and Post Harvest practices
If well managed, nutmeg starts to bear at the 7th year and harvest increases with time. Productive age of nutmeg is uncertain as it can give good crop more over hundred years. However peak harvest comes after 20 years of age.
Yield of nutmeg vary from tree to tree from several nuts to 8000-10000 nuts per tree. Average yield is 1500dry nutmeg/tree/year and 1-1.5kgdry mace/tree/year.
As soon as fruits split or about to split they are hand picked from the trees. Fruits are opened by hand and the mace is removed from the nut by cutting with a small pointed knife where it is attached to the base of the nut. The nuts are dried until the kernel rattles in the shell. Dried nutmeg can be sold as it is or can be shelled and sold only the kernel.
The mace is flattened by hand and dried slowly under the sun until a bright orange-yellow fragrant product is obtained.
Standard quality specifications
Shell consist of well dried mace containing not more than 5% of pieces less than one forth of the size of the normal whole mace.
Shell consist of well dried mace in pieces
Moulds and Insects: Shall not be ore than 3% by mass in either grade
Extraneous Matter: Shall not be more than 1% by mass in either grade
Medicinal and Chemical Properties