Notices 1 Effective January 2007, the Discussion Paper series within each division and the Director General's Office of IFPRI were merged into one IFPRI-wide Discussion Paper series. The new series begins with number 00689, reflecting the prior publication of 688 discussion papers within the dispersed series. The earlier series are available on IFPRI's website at http://www.ifpri.org/publications/results/taxonomy%3A468. 2 IFPRI Discussion Papers contain preliminary material and research results. They have been peer reviewed, but have not been subject to a formal external review via IFPRI's Publications Review Committee. They are circulated in order to stimulate discussion and critical comment; any opinions expressed are those of the author(s) and do not necessarily reflect the policies or opinions of IFPRI.

No abstract

Banana is an important crop in the Kagera region of Tanzania. Banana xanthomonas wilt (BXW) was first reported in Kagera in 2006, and is now an important limiting factor in banana production, because all cultivars are susceptible and infected plants can fail to produce fruit. BXW is caused by Xanthomonas campestris pv. musacearum (Xcm), which is spread by farm tools, infected planting materials, and pollinating insects. Practices that address Xcm dissemination, such as mat removal, debudding and tool sterilization, have not prevented the spread of BXW in the region. Disease surveys were conducted in Kagera from 2007 to 2011 to assess BXW presence, monitor its intensity and evaluate its socioeconomic impacts. Spatiotemporal clusters of BXW were analysed with ARCGIS and SAS. The relationship between BXW clusters and environmental variables was examined using bivariate correlations in SPSS; two modelling approaches, MaxEnt (maximum entropy) and logistic regression, were used to predict the potential distribution of BXW in Tanzania. Disease progress over time was best described with the Gompertz model. Significant clustering of BXW was observed in all years and hotspots were located in the Muleba, Karagwe, Misenyi and Bukoba rural districts. These findings suggest that BXW spreads rapidly over short distances. BXW clusters were positively correlated with rainfall and negatively with temperature and altitude. According to MaxEnt, precipitation was the main factor associated with BXW development. MaxEnt and logistic regression predicted a wide potential distribution of BXW in Tanzania because the climate in all banana-growing regions is conducive for its establishment.

Banana is a key crop in the livelihoods of many people in the Great Lakes region of East and CentralAfrica. For more than a decade now, the crop has been threatened by Banana Xanthomonas Wilt (BXW) which has spread throughout the region but at different rates. The disease attacks all banana cultivars and can cause up to 100% yield losses at farm level if effective control measures are not put in place. However, limited information on impact of BXW at regional level is available to guide interventions. Thus, this study assessed the impact of BXW on farmers' livelihoods in Kagera basin of Tanzania, Burundi and Rwanda. A total of 436 households (Tanzania 120, Burundi 208 and Rwanda 108) mostly from major banana-producing and BXW-affected districts were sampled and interviewed in a household survey. Thirty-three to seventy-five of the total banana mats per farm in the three countries were infected with BXW. Banana production losses caused by BXW were valued at US$ 10.2 million and US$ 2.95 million in Tanzania and Rwanda, respectively, banana sales by farmers dropped by 35% while bunch prices unpredictably doubled. Since banana is a key component of these farming communities, the banana production losses resulted in significant reduction in household food security and incomes. To cope with these challenges, most households are diversifying into other food crops such as maize, cassava and sweet potatoes. This poses a number of socio-economic and biological implications that require further investigation.

No abstract