University of Zimbabwe

About: University of Zimbabwe is a education organization based out in Harare, Harare, Zimbabwe. It is known for research contribution in the topics: Population & Acquired immunodeficiency syndrome (AIDS). The organization has 4378 authors who have published 6800 publications receiving 160720 citations. The organization is also known as: UZ & University College of Rhodesia and Nyasaland.

Whole-tree level water balance and its implications on stomatal oscillations in orange trees [Citrus sinensis (L.) Osbeck] under natural climatic conditions.

Abstract: Sustained cyclic oscillations in stomatal conductance, leaf water potential, and sap flow were observed in young orange trees growing under natural conditions. The oscillations had an average period of approximately 70 min. Water uptake by the roots and loss by the leaves was characterized by large time lags which led to imbalances between water supply and demand in the leaves. The bulk of the lag in response between stomatal movements and the upstream water balance resided downstream of the branch, with branch level sap flow lagging behind the stomatal conductance by approximately 20 min while the stem sap flow had a much shorter time lag of only 5 min behind the branch sap flow. This imbalance between water uptake and loss caused transient changes in internal water deficits which were closely correlated to the dynamics of the leaf water potential. The hydraulic resistance of the whole tree fluctuated throughout the day, suggesting transient changes in the efficiency of water supply to the leaves. A simple whole-tree water balance model was applied to describe the dynamics of water transport in the young orange trees, and typical values of the hydraulic parameters of the transpiration stream were estimated. In addition to the hydro-passive stomatal movements, whole-tree water balance appears to be an important factor in the generation of stomatal oscillations.

Zinc supplementation in pregnancy.

Abstract: Background It has been suggested that low serum zinc levels may be associated with abnormalities of labour, although this has not yet been established. Objectives The objective of this review was to assess the effect of zinc supplementation in pregnancy on maternal and fetal mortality and morbidity. Search strategy The Cochrane Pregnancy and Childbirth Group trials register was searched. Selection criteria Acceptably controlled trials of zinc supplementation in pregnancy. Data collection and analysis One reviewer assessed trial quality and extracted data. Study authors were contacted for additional information. Main results Seven trials were included. Apart from possible reduction in induction of labour, caesarean section and preterm delivery in the supplemented group, no other differences were detected between groups of women who had zinc supplementation and those who had either placebo or no zinc during pregnancy. Reviewer's conclusions There is insufficient evidence to evaluate fully the affect of zinc supplementation during pregnancy. The possible beneficial effects on preterm delivery need to be evaluated in further trials.

The acquisition and use of miombo litter by small-scale farmers in Masvingo, Zimbabwe

Abstract: A questionnaire survey of fifty-two small-scale farmers was conducted to elucidate the practices associated with acquisition and use of miombo litter. On average, a household cropped 3.7 ha of land and owned ten head of cattle. Farmers collected, on average, 0.5 t of litter per household per annum with larger amounts collected by those with more cropland and more cattle. Cattle ownership is related to quantities of litter collected and the destination of the collected litter, most of the litter being cured in cattle pens. Farmers with less area of cropland applied greater quantities of litter per hectare of cropland than did farmers with more cropland. On average, five tons per hectare per season of the manure-litter mixture is applied to crop fields with litter contributing, on average, 0.12 t/ha to the mixture. Some crops, particularly maize and fingermillet, are more likely to receive litter than other crops.

Prevalence and intensity of schistosomiasis in two rural areas in Zimbabwe and their relationship to village location and snail infection rates.

Abstract: Surveys for schistosomiasis of 2498 people of various ages from 22 villages in northeast Zimbabwe are reported. A high prevalence of Schistosoma haematobium (53·1%) and a medium prevalence of S. ma...

Small farms and development in sub-Saharan Africa: Farming for food, for income or for lack of better options?

Abstract: Most food in sub-Saharan Africa is produced on small farms. Using large datasets from household surveys conducted across many countries, we find that the majority of farms are less than 1 ha, much smaller than previous estimates. Farms are larger in farming systems in drier climates. Through a detailed analysis of food self-sufficiency, food and nutrition security, and income among households from divergent farming systems in Ethiopia, Ghana, Mali, Malawi, Tanzania and Uganda, we reveal marked contrasts in food security and household incomes. In the south of Mali, where cotton is an important cash crop, almost all households are food secure, and almost half earn a living income. Yet, in a similar agroecological environment in northern Ghana, only 10% of households are food secure and none earn a living income. Surprisingly, the extent of food insecurity and poverty is almost as great in densely-populated locations in the Ethiopian and Tanzanian highlands that are characterised by much better soils and two cropping seasons a year. Where populations are less dense, such as in South-west Uganda, a larger proportion of the households are food self-sufficient and poverty is less prevalent. In densely-populated Central Malawi, a combination of a single cropping season a year and small farms results in a strong incidence of food insecurity and poverty. These examples reveal a strong interplay between population density, farm size, market access, and agroecological potential on food security and household incomes. Within each location, farm size is a major determinant of food self-sufficiency and a household’s ability to rise above the living income threshold. Closing yield gaps strongly increases the proportion of households that are food self-sufficient. Yet in four of the locations (Ethiopia, Tanzania, Ghana and Malawi), land is so constraining that only 42–53% of households achieve food self-sufficiency, and even when yield gaps are closed only a small proportion of households can achieve a living income. While farming remains of central importance to household food security and income, our results help to explain why off-farm employment is a must for many. We discuss these results in relation to sub-Saharan Africa’s increasing population, likely agricultural expansion, and agriculture’s role in future economic development.