Different Parts Of Kenya Research Articles

Bruchid infestation of cowpea varieties in the field

Cowpea is one of the most widely grown leguminous crops in Africa: in Kenya it occupies over 66,000 ha and Coast Province ranks second to Eastern Province with about 5200 ha. It is an important food item consumed both as a vegetable and as a grain. Unfortunately, it suffers from both preharvest and postharvest infestations which accounts for serious losses of the crop. With the introduction to Kenya of improved varieties from IITA, Nigeria, such losses would be increased due to varying susceptibility in different pest ecosystems. The objective of this study therefore was to observe the infestation of the IITA varieties and compare them with local cowpea varieties collected from different parts of Kenya. The work was conducted at C.A.R.S., Mtwapa from 1979 to 1981 inclusive. From the study, five different bruchid species were identified as infesting cowpea varieties in the field. These were Collosobruchus rhodensienus; C. phaseoli; C. chinensis; Bruchidius atrolineatus; and C. analis; in order of decreasing abundance. Over 50% of the bruchids found in the field were C. rhodensienus while Zabrotes spp. and C. maculatus (F) were never encountered in the field. Although the IITA materials were introduced because of their yield potential, it was found that some of them were as susceptible to preharvest bruchid attack as the locally available materials. The short rains season had more bruchid infestations than the long rain season. There were also fewer eggs on pods of local varieties and fewer bruchids emerging from seeds of local as compared to IITA varieties. The results however were not significantly different. Further work should be done to establish the complex of bruchids found in stored cowpea varieties, the losses caused and control measures applicable to reduce damage.

Effects of Environment and Cultural Conditions on Potassium, Calcium and Magnesium in Coffee Leaves

SummaryPotassium, calcium and magnesium in coffee leaves are presented as total K + Ca + Mg in dry matter and as percentages (proportions) of this sum. Brazilian coffee and leaf samples collected in different parts of Kenya generally fell within the normal ranges of values reported from the Kivu area in the Congo Republic. Data for Kenya coffee leaves are examined for the influence of season, cultural treatments such as organic mulch and fertilizers, and cropping level, on the concentration and balance of the nutrients.

Serological survey of plague in rodents and other small mammals in Kenya

During a survey from 1963 to 1966 over 8000 sera from rodents and other animals from different parts of Kenya were tested for HA antibodies to the fraction 1 antigen of P. pestis. HA antibodies were present in high titre (1 in 512 to 1 in 2048) in sera from Arvicanthis niloticus, Praomys natalensis, Rattus rattus, and Acomys spp. and in lower but significant titres (1 in 16 in 256) in sera from Otomys angoniensis, Aethomys kaiseri, Tatera spp. Lemniscomys striatus, L. griselda and Rhabdomys pumilio. Serum from a Thamnomys dolichurus reacted at 1 in 256. Other animals tested included a few genet cats ( Genetta tigrina), bush squirrels ( Paraxerus ochraceus) dwarf mongooses ( Helogale parvula), an African striped polecat ( Ictonyx striatus) and a giant elephant shrew ( Petrodromus tetradactylus); of these, sera from a Helogale reacted at 1 in 32 and from a Petrodromus at 1 in 256; the other animals were negative. In 1962–1965 10% of the sera were positive and in 1966 only 6%. The percentage of sera positive in 1962–1965 was very high at Kisumu (41%) and at Taveta (42%); at Rongai only 2%. Quite high positive rates were found at Kombeni and Mombasa (both 13%), and at Malindi (16·5%). The positive rate in the Nairobi area was 7%; in 1966 this had fallen to 1%. Since 1950 human plague has occurred sporadically in the Nairobi area (Kiambu in 1952), at Rongai (1952, 1954) and at Konza (1953) near Masaku. It was not uncommon at Nyeri, but a serological survey remains to be done. There are grounds for believing that the permanent reservoir of plague is frequently associated with foothill areas, at medium altitudes. This does not account, however, for its evident persistence in such low-lying coastal areas as Mombasa, Kombeni and Malindi. The HA test is reliable. It remains to explain the persistence of P. pestis in the absence of overt signs of plague by isolating and studying strains from different localities, when the serological results indicate its continued existence.

The Aetiology of Bovine Petechial Fever (Ondiri Disease)

SUMMARY Evidence is presented indicating that bovine petechial fever (B.P.F., Ondiri disease) is associated with, and possibly caused by, a rickettsia-like organism. This organism has been found in cattle in different parts of Kenya where B.P.F. is known to occur enzootically. It is highly pleomorphic and has been observed in neutrophils, large lymphocytes, monocytes and eosinophils of the circulating blood and in the large lymphocytes of the spleen. Morphologically, it resembles members of the Erlichia group but appears to differ in certain aspects from other known members. It is suspected that wild ruminants act as reservoirs of infection and that a tick is the vector.