A total of 93 isolates of Xanthomonas campestris pv. phaseoli was collected from five countries over a wide range of altitude (500–2320 m above sea level) in eastern Africa. Collections were made from a range of cultivars of the common bean (Phaseolus vulgaris), including known sources of resistance, as well as from wild alternative but symptomless hosts including Senna (Cassia) hirsuta and Digitaria scalarum. From these, 30 isolates were selected for detailed characterization. Although variation was found in parameters including phage type, the production of brown pigment in culture media and in‐vitro growth rate, there was little consistent relationship between these characters and pathogenic variation. Studies of pathogenic variation among the 30 isolates on 20 genotypes of P. vulgaris revealed quantitative host non‐specific differences (aggressiveness). On tepary bean (P. acutifolius), however, the 30 isolates interacted differentially with the genotypes and eight distinct physiologic races of X. c. pv. phaseoli were defined, suggestive of an underlying gene‐for‐gene relationship. Despite this apparent gene‐for‐gene interaction, resistance to common bacterial blight in P. vulgaris, derived from earlier use of P. acutifolius, has apparently remained non‐specific and essentially durable. It is suggested that, since levels of resistance already available within P. vulgaris provide adequate protection, bean breeders should resist the temptation to incorporate new complete resistance from P. acutifolius as it would risk destabilizing the host–bacterium relationship by introducing race‐specific resistance that is more likely to prove transient in agriculture.

A medicinal plant study was carried out in eighteen parishes and 54 villages of Erute county, Lira district, Uganda. Parishes and villages were selected using stratified random sampling techniques. Questionnaires, interviews and discussions with the local people were used to obtain information on the names of the plants, their medicinal uses and conservation methods. The number of the medicinal plants species used was 180 belonging to 144 genera and 57 families of flowering plants. The major families recorded for medicinal purpose included Fabaceae (37 species), Asteraceae (26 species), Euphorbiaceae (eleven species), Vitaceae (eight species), Verbenaceae (seven species), Poaceae (six species), Solanaceae (five species), and Rubiaceae (four species). There is a need for putting in place measures to conserve these plants. Unfortunately, most of the healers or users were not interested in cultivation of the plants. The situation could worsen with the social changes and demand for land for agriculture in the district.

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Rural–urban migration in developing countries is considered to be a key process for sustainable development in the coming decades. On the one hand, rural–urban migration can contribute to the socioeconomic development of a country. On the other hand, it also leads to labor transfer, brain-drain in rural areas, and overcrowded cities where planning is lagging behind. In order to get a better insight into the mechanisms of rural–urban migration in developing countries, this paper analyzes motivations for rural–urban migration from the perspective of rural households in Uganda. A total of 1015 rural households located in southwestern Uganda were surveyed in 2019. A total of 48 percent of these households reported having at least one out-migrant. By means of logistic regression modeling, the likelihood for rural out-migration was assessed using household- and community-level socioeconomic characteristics as predictors. The results show that most out-migrants are from relatively wealthy households with a higher-than-average education level. Typically, these households are located in villages that are well connected with urban centers. Poor households in remote locations send significantly fewer migrants because of their limited access to migration information and poor transport networks. From these findings, the following policy recommendations are made: Firstly, efforts should be made to extend basic social services, including quality education, towards rural areas. Secondly, in order to reduce socially disruptive long-distance migration and the eventual overcrowding and sprawls of major cities, government investments should be oriented towards the upgrading of secondary towns, which can offer rural out-migrants rewarding employment and business opportunities.

Relative growth rate (RGR) is an important parameter in plant growth models. However, no field measurements of RGR have been made in Cyperus papyrus (papyrus) wetlands. In this study, the growth dynamics of aerial shoots were investigated in a tropical papyrus wetland. The aim was to estimate temporal changes in the growth rates, and also establish the effect of water level and temperature change on total culm number, culm recruitment and senescence. Dry weights of shoots during their life cycle were determined using a non-destructive method after establishment of relationship between culm diameter and dry weight. Measurements were made over period of seven months. During the course of the measurements, culm density significantly increased from 16.1 to 35.9 culms•m −2 . There were significant changes in both culm recruitment and senescence. Maximum RGR of developing culms was 1.04 g g −1 d −1 . Using a culm density of 27 per m −2 , productivity range was 16.74 to 37.37 g m −2 d −1 . There was an inverse and significant relationship between rate of change in leaf weight ratio (LWR) and RGR of the culms. In conclusion, RGR of the aerial shoot development was controlled by rate of change in LWR from 41 to 156 days of growth. There was a strong and negative influence of water level fluctuation on total culm density.