Mangbettu

MANGBETTU (Monbuttu), a negroid people of Central Africa living to the south of the Niam-Niam in the Welle district of Belgian Congo. The Mangbettu were some of the most in veterate cannibals in Africa. Physically the Mangbettu differ from their negro neighbours, are not so black and are less negroid, many having quite aquiline noses. The beard, too, is fuller than in most negroes. The men wear bark cloth, the women a simple loin cloth, often not that. Both sexes paint the body in elaborate designs. As potters, sculptors, boatbuilders and masons the Mang bettu have had few rivals in Africa. Their huts, with pointed roofs, were larger, better built, and cleaner than those of their neighbours, and some of their more important buildings were of great size and exhibited some skill in architecture.

See G. A. Schweinfurth, Heart of Africa (1874) ; W. Junker, Travels in Africa (189o) ; G. Casati, Ten Years in Equatoria (1891) ; C. van Overbergh and Ed de Jonghe, Les Mangbetu (19o9).

or MANGOLD, a variety of the comm

on beet, known botanically as Beta vulgaris. The name is German and means literally "Root of Scarcity," a name perhaps given because it often produces a large yield when other crops fail. R. C. A. Prior (Popular Names of British Plants) says it was originally mangold, a word of doubtful meaning, which is still applied to it. The root is a store of carbohydrate food-stuff in the form of sugar, which is formed in the first year of growth when the stem remains short and bears a rosette of large leaves. If the plant be allowed to remain in the ground till the following year strong leafy angular aerial stems are developed, 3 ft. or more in height, which branch and bear the inflorescences. The flowers are arranged in dense sessile clusters subtended by a small bract, and resemble those of the true beet. The seeds are clusters of "spurious" fruits ; hence several seeds are present in one "seed" of commerce, which necessitates the careful thinning of a young crop, as several seedlings may spring from one "seed." There are five chief varieties : (a) Long varieties, (b) Ox-horn varieties, (c) Intermediate or gatepost, (d) Tanbard, (e) Globe; and among these are subvarieties; for example, there is the Golden Tanbard with orange-coloured skin and yellow zones in the flesh, and crimson Tanbard with crimson skin, and flesh with crimson zones.

This plant is very susceptible of injury from frost, and hence in the short summer of Scotland it can neither be sown so early nor left in the ground so late as would be requisite for its mature growth. But it is peculiarly adapted for those southern parts of England where the climate is too hot and dry for the successful cultivation of the turnip. In feeding quality it rivals the swede; it is much relished by livestock—pigs especially doing remarkably well upon it ; and it keeps in good condition till midsummer if required. The valuable constituent of mangold is dry matter which averages about 12% as against 11% in swedes. The chief nutri tive ingredient is cane sugar which may be 3-4% in the long red varieties and 7-8% in the Golden Tanbard and Globes. It is exempt from the attacks of the turnip beetle.

For further details, see Robbins, Botany of Crop Plants (Phila delphia, 1924) and J. Percival, Agricultural Botany (London, 1926).

Cultivation.

The special value of the crop is in its produc tiveness, in the succulence and long keeping qualities of its roots, and in its adaptability for districts which are too warm and dry for turnip cultivation. In the cooler northern half of Great Britain and in the upland parts of the Midlands, mangolds occupy a relatively small area ; where climatic conditions are not unfavourable, how ever, good yields can be secured on most soils by suitable methods of cultivation, including liberal manuring and attention to the soil reaction. Mangolds are sensitive to soil acidity.

.Mangolds are sometimes grown continuously, but more com monly occupy a part of the fallow course in a rotation. This crop succeeds best when the requisite deep working and manuring oper ations have been completed in the previous autumn or winter. The preceding corn stubble should be skimmed and cleaned dur ing September, and, after about 20 tons per acre of yard manure have been applied, it should be ploughed deeply before Christmas. In March the soil should be lightly stirred as soon as dry enough, and a mixture of 3 cwt. of superphosphate and 4 cwt. of kainit per acre should be given. Further and gradually deeper stirring of the soil should be performed in March or early April. Where the crop is to be drilled on ridges, these should be formed about the end of March, the requisite application of i to i 2 cwt. of sulphate of am monia being applied before ridging. The soil should lie undis turbed for some three weeks before drilling, but when ready to sow, the surface should be again lightly stirred with chain harrows.

About the third week in April is an average suitable date for sowing. The seed may suitably be drilled at a depth of about in. and in rows about 24 in. apart. A liberal allowance of seed, io lb. per acre, is desirable.

Horse- and hand-hoeing begin as soon as the lines of plants are clearly visible. The plants are next bunched out, and as soon as they have four leaves they are singled out to about 1 o in. apart. A top dressing of 1 to II- cwt. of nitrate of soda is now given. Two, or if necessary three, further horse hoeings and a second hand hoe ing complete the after-cultivations of the crop ; but it is desirable that deep working between the rows should cease by the middle of July, by which date the root fibres have begun to extend across the spaces between the rows.

Harvesting takes place in October before the incidence of frosts, to which the roots are susceptible. Unlike turnips and potatoes, mangolds may be stored in large heaps, and dampness at the time of lifting and storing does not impair their keeping qualities. The average yield is 19 tons per acre, which represents a greater amount of digestible matter than any other crop grown in Britain. Under favourable conditions, yields more than double this figure are obtained. Where good crops of mangolds can be grown, no other crop produces digestible nutriment at so low a cost per unit.