Chapter 9: Crop Plants and Exotic Plants


Chapter 9: Crop Plants and Exotic Plants


NUTMEG AND MACE
Myristica fragrans Houtt., family Myristicaceae

Nutmeg and mace are produced in the tropical areas of Indonesia and the West Indies. Purseglove (1968*) indicated that annual production of nutmeg amounted to about 170,000 cwt (1 cwt = 112 lb). About 1 pound of mace is obtained for each 10 pounds of nutmeg. This would indicate that between 15,000 and 20,000 cwt (2,240,000 lb) of the volume produced was mace.

Plant:

The nutmeg tree is bushy, 30 to 40 feet tall, resembles an apricot, and the trees are usually spaced about 30 feet apart. It produces a pale orange-yellow fruit about 2 1/2 inches long, that resembles an apricot, but when ripe the l/2 inch thick husk separates into two pieces, disclosing the dark-colored nut, covered with a brilliant scarlet network (aril) known as mace (Nicholls and Holland 1929). When the nuts are harvested, the aril is separated from the nut and sold as mace, and the nut marketed as nutmeg. The seeds must be planted within 3 days after harvest or the viability is lost. The plant will begin fruiting at 5 to 6 years of age, but is at its best by 15 years and will remain at this productive level another 10 to 20 years (Ridley 1912*). A plant may produce 1,800 fruits in a year, yielding 20 pounds of nutmeg and 2 pounds of mace (Nicholls and Holland 1929).

Inflorescence:

The nutmeg tree is dioecious, with male flowers on one tree and female flowers on another. Occasionally, a plant may have a few flowers of the opposite sex, that is, a male tree may have a few female flowers. Occasionally, also, the sex of the plant may change entirely, particularly it may change from all male or staminate flowers to completely female or pistillate flowers (Ridley 1912*).

The bell-shaped pendant, light-yellow flowers are in small cymes on a woody stalk one-half inch in diameter. The 5- to 10-mm male flowers are more globose than the female ones, and have a mass of cylindrical stamens 8 to 12 mm and extending to the flower opening. The slightly larger (10 mm) female flowers, seldom over three in a raceme, are dilated at the base, with a tiny, two-lobed stigma and an ovary that largely fills the corolla. Nectar is produced in both types of flowers at the base of the corolla. The development from flower to ripe fruit requires 6 to 9 months (Flach and Cruickshank 1969). There may be three flowering cycles during the year.

Pollination Requirements:

There seems to be little doubt that cross-pollination is required between trees as there are insufficient flowers of both sexes on any one tree. The pollen must be transported to the numerous pistillate flowers to set the 1,500 to 2,000 nuts expected per year on a mature tree.

Pollinators:

Nutmeg is insect pollinated, but there is lack of agreement as to what insects are responsible. Flack and Cruikshank (1969) stated that "natural pollination is carried out by a moth." Ridley (1912*) stated that he had seen only small bees and small beetles visit the flowers. Nicholls and Holland (1929) stated that pollination is effected only by wind and insects. Purseglove (1968*) said that pollination is probably effected by small insects. It becomes evident that there is insufficient information on the pollination of this crop, but logically its pollination is by insects.

Pollination Recommendations and Practices:

None, yet the evidence indicates that for stable production the grower of nutmeg should arrange for a stable pollinator population on these flowers.

LITERATURE CITED:

FLACH, M., and CRUICKSHANK, A. M.
1969. NUTMEG. In Ferwerda, F. P., and Wit, F., eds. Outlines of Perennial Crop Breeding in the Tropics, pp. 329-338. H. Veenman and Zonen, N. V. Wageningen, The Netherlands.

NICHOLLS, H. A., and HOLLAND, J. H.
1929. A TEXTBOOK OF TROPICAL AGRICULTURE. 639 pp. Macmillan & Co., Ltd., London.


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