Kivu Region Research Articles

Partial replacement of local common bean mixtures by high yielding angular leaf spot resistant varieties to conserve local genetic diversity while increasing yield

SummaryThe effect of replacing proportions of local farmer bean (Phaseolus vulgaris) mixtures with varieties resistant to angular leaf spot on grain yield was evaluated under local disease pressure in the Kivu region of Zaire. Local bean mixtures in on‐station and in multi‐locational trials containing respectively 25%, or 50% of Centro Internacional de Agricultura Tropical (CIAT) breeding lines BAT76, or A285, resistant to angular leaf spot yielded significantly more than the local mixture alone. Yields exceeded expected values in three seasons of on‐station testing and in two seasons of multi‐locational trials. Yield over the expected was found to be a property of new mixtures not protected with fungicide and were attributed to disease control. Relative to expected yields non‐protected farmer mixture components performed 17% and 16% better than in protected plots and A285 components yielded 24% and 16% better at respectively 25% and 50% A285 supplementation levels. A285 increased yields of the local mixture components and benefitted from the local mixture when not protected by fungicide. Yield increases in multi‐locational trials were largely attributed to the higher yield potential of the resistant variety A285, although angular leaf spot severity was significantly reduced. It was concluded that high yielding, resistant varieties were able to increase bean yield in the region, but probably at a substantial cost in genetic diversity in farmer bean mixtures. That said, a partial replacement strategy is preferable to strategies which encourage complete replacement of local germplasm with one or few high yielding varieties.

Kings and Clans: Ijwi Island and the Lake Kivu Rift, 1780-1840

This book questions the assumption that clans, as traditionally defined by anthropologists and historians, are static structures that hamper political centralization. By reconstructing the history of kings and clans in the Kivu Rift Valley at a time of critical social change, this book enlarges our understanding of social process and the growth of state power in Africa. In the early 19th century many factors contributed to the creation of new social relations in the Lake Kivu region - ecological change, population movement, the expansion of the Rwandan state from the east, the rise of new political units to the west and the movement of many population groups and their rural forms through the area. This book looks at the role of clans in the establishment of a new kingdom on Ijwi Island in Lake Kivu. Drawing on detailed ethnographic observations of the social and ritual organizations of Ijwi society, oral data and evidence from written sources, this book shows that the clans of Ijwi were not static formations, nor did the establishment of a royal family on the island emerge from military conquest and internal social breakdown.

La Connaissance des Ophidiens dans le Bulega (Kivu, est du Zaire)

The Lega in the Kivu Region, Eastern Zaire, have rich knowledge of the snake fauna. The snakes have social significance in their legends, folktales and proverbs, in which they incarnate a naughty and vagrant man, and arc responsible for certain problems in the village. The Lega distinguish and classify the snakes empirically according to their body color, size, temperament and biotope in which they live. Larger snakes are eaten and the skin is sold. Snake bite is treated by some plant medicine, for which phytochemical analysis is being carried out.

Snakes of Zaire and Their Bites

The ophidiological survey made in Zaire revealed the presence of 152 species of snakes included in 60 genera and in 8 families. The family Colubridae contains the largest num­ ber of genera (45) and species (97). Their geographical distribution shows that the eastern part of Kivu region contains a wide variety of species (90 species). The density ofZairean snakes has not yet been known. But in some localities like Kamanyola in the Kivu province, the density is as high as 80 individuals per square kilometer for Ihe vipers. Other area5 like Kinsuka in the vicinity of Kinshasa has as many as 10 species within the same area. Snakes arc found in the forest, the savanna and in the aquatic milieu. Some species are arboreal and others live in the mountain regions. Evolutionary considerations based on the anatomical observations indicate that the equatorial forest of the Northern Zaire contains some of the most ancient and conserva­ tive forms of snakes. Some are considered to be the most evolved and specialized fom1 of snakes in the world. The frequencies of the snake bites at the sanitary sectors are surveyed. According to the epide­ miological data on snake bites, envenomations constitute a serious problem for the public health. \1ortality is 6 to 14.3% (mean 8%) of the total snake bites from 1979 to 1986. Bites are most fre­ quent during the agricultural activities. In the savannaofK ivu, which shows the tropical climate, the bites are recorded in the rainy season. The dangerous snakes have been identified: 79 species (51 o/c) are venomous, including vipers, elapids and opisthoglyphous colubrids which are the most dangerous. The treatment of snake bites to reduce mortality and morbidity is applied ac­ cording to the principles of modem medicine (using antivenom sera) and of the traditional methods (using traditional drugs). The phytotherapy against envenomation is known in Zaire and in many other countries of Africa. Phytochemical screening of these plant drugs is being made for testing their biological activities, and the pharmacological analysis is being carried out for the confirmation of the presence of any anti venomous substance.

Serum levels of prolactin and milk production in women during a lactation period of thirty months.

Serum prolactin was measured in single blood samples collected from 219 nursing mothers of the Kivu region (Zaïre) during 30 post-partum months. In addition the number of feeding episodes per day and the amount of milk given to the child in 24 h were recorded. The mean serum prolactin levels remained around 1000 mu/l during the first 15 months of lactation and fell during the next 3 months to 550 mu/l. A decline in milk production per day occurred during the second year, but it was less marked than that of prolactin. This decline seemed to be associated with the decline in suckling frequency as the quantity of milk given per feed remained almost unchanged throughout lactation. The average amount of milk given by mothers with serum prolactin levels in the range of values seen in non-lactating and non-pregnant women (about 500 mu/l) is nevertheless of some 35 g per feeding or 260 g per day. These results demonstrate that milk production can be maintained in women with normal levels of prolactin and suggest that prolactin plays a permissive role in established lactation.

Evolution et structure de la population de Bukavu

The Growth and Structure of the Population of Bukavu. Bukavu, the largest city of the Kivu Region and also the capital of it, is experiencing an extremely strong demograhic growth. This growth was especially dynamic during the first years following indépendance because of a rural exodus upon which little or no control was exercised .. Urban immigration is all the greater in that the average population density of the Bukavu hinterland is the highest in the country. As it is generally young couples who migrate, they found families in the city. Thus natural increase is another factor in the demographic growth of the city.

Hyperprolactinaemia during prolonged lactation: evidence for anovulatory cycles and inadequate corpus luteum.

Serum progesterone and prolactin were measured in single blood samples collected from 176 mothers during a lactation period of 2 years and from fifty-six non-lactating, non-pregnant and regularly menstruating women from the Kivu region (Zaïre). On the basis of serum progesterone levels, evidence of corpus luteum activity was obtained in 61% of non-lactating women; but only 20% of non-amenorrhoeic lactating mothers. This suggests an increased incidence of anovulatory cycles and/or cycles with short luteal phases among nursing mothers. The incidence of corpus luteum activity was 8% in amenorrhoeic lactating mothers. In this 8% recurrence of ovulation preceded return of menstruation. Mean serum progesterone was significantly higher and serum prolactin significantly lower in the non-lactating women than in the nursing mothers. This suggests that although ovulation occurs, corpus luteum activity is inadequate in hyperprolactinaemic nursing mothers.

SIBLING SPECIES OF SMALL AFRICAN HONEY‐GUIDES

SUMMARYIt is now clear that Indicator exilis does not have so extensive a range or so many geographic races as were attributed to it only a few years ago. Alongside exilis, over a large part of its distribution in forested tropical Africa, lives a sibling species, I. willcocksi, of somewhat more greenish colouration, usually more streaked on the crown. On the higher mountains in the Kivu region of Central Africa dwells a third species, I. pumilio, of small size, with beak proportionately still smaller. A fourth species, I. meliphilus, markedly paler grey beneath than any of the preceding, is restricted to rather dry regions from eastern Africa to Nyasaland and Angola. Many details of distribution and geographic variation will require further investigation.

Correlation between the Fat and the Protein Content of Human Milk

I HAVE undertaken a study of the chemical composition of mature human milk (excluding colostrum) in the Kivu region of the Belgian Congo. The analyses were done on 250 samples of all the milk secreted during 24 hr. by mothers belonging to the Bashi tribe. This ethnic group lives along the eastern shore of Lake Kivu (about long. 29° E. of Greenwich) in the Belgian Congo, between latitudes 2° 10′ S. and 2° 40′ S. at an altitude varying from 1,460 to 2,000 metres above sea-level. Their staple foods are beans, sweet potatoes and beer made from bananas. Demaeyer took the samples in his quantitative study of milk secretion.