In October 2001, a wilting disorder of new aetiology was reported affecting banana ( Musa sp.) within the Mukono district of Uganda. The disorder was characterized by a rapid yellowing and wilting of the younger leaves, a discoloration of the internal vascular vessels, occasionally a dieback initiating from the male floral parts with internal rotting of banana fruits. These symptoms were notably distinct from fusarium wilt ( Fusarium oxysporum ) and 'Matooke wilt' (a wilt-like disorder of unknown aetiology), but strongly resembled Moko disease caused by Ralstonia solanacearum , although this particular pathogen had not previously been recorded on banana in Africa.A bacterium was isolated on nutrient agar that was identified by fatty acid (Microbial ID Inc. [MIDI]) and metabolic (Biolog, Inc, Hayward, CA, USA) analyses as Xanthomonas axonopodis (ID probability score < 0·4) and Xanthomonas campestris (ID probability score ∼ 0·9), respectively. The presence of the Xanthomonas specific fatty acids 11:0 ISO, 11:0 ISO 3OH and 13:0 ISO 3OH was recorded. Pathogenicity tests on disease-free tissue culture-derived banana plantlets by stem inoculation with a bacterial suspension induced wilt symptoms consistent with field observations after 3 weeks. Reisolation and identification, as outlined above, confirmed Koch's postulates. Reference to the literature suggested the bacterium was Xanthomonas campestris pv. musacearum (Yirgou & Bradbury, 1968). However, this bacterium is relatively poorly described and not contained within either the MIDI or Biolog databases. To support the identification, rep-PCR (Louws et al ., 1994) using ERIC and BOX primers was performed on the Ugandan banana isolate, cultures of X. campestris pv. musacearum from Ensete and Musa in Ethiopia (IMI 349461, IMI 349986, IMI350025) and other cultures of Xanthomonas spp. from Africa. These analyses revealed an identical DNA fingerprint for all isolates from Musa and Ensete , but distinct fingerprints for the isolates from other hosts. This is the first report of X. campestris pv. musacearum outside of Ethiopia, where it is recorded as a pathogen of ensete and, to a lesser extent, banana. Accordingly, this pathogen has been given the common name of ensete bacterial wilt, although the aptness of this now looks questionable. The risk posed by this new disease record to the contiguous banana plantation of Uganda is undetermined, but significant spread is already being observed. The causative organism for this new disease record has been deposited within the CABI Genetic Resource Collection as IMI 386970. References

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Coffee wilt disease (CWD) caused by

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This chapter describes recent advances in the breeding for coffee wilt disease (Gibberella xylarioides) resistance in Africa. It covers the screening, evaluation and multiplication of resistant cultivars and their impact of resistance on sustainable coffee production.

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This chapter describes the current status of coffee wilt disease (CWD, Gibberella xylarioides) in Uganda, including its occurrence and distribution, its impact on coffee production, the factors affecting its severity and incidence, and country-specific practices for its control.

Tomato (Solanum lycopersicum L.) is a priority vegetable in Uganda, but due to its limited genetic base, its cultivated types are prone to a variety of diseases. The objective of this study was to evaluate new tomato genotypes for resistance to major tomato diseases under hotspot conditions in Uganda. Fourty-five tomato genotypes were evaluated for reactions to tomato bacterial wilt, tomato bacterial speck, early blight and late blight. The study was conducted for two rainy seasons in 2019, at the National Crops Resources Research Institute, Namulonge in Uganda. Data for severity and incidence were collected at two-week intervals after transplanting. Twelve genotypes (Nouvella F1, Rambo F1, Commando F1, AVTO1315, AVTO922, AVTO1701, AVTO1219, AVTO1464, MT56, ADV1287A, Pruna and Vega) exhibited high levels of tolerance to bacterial wilt; while bacterial speck presented mild symptoms majorly seen on Vega, Zodiac and AVTO9802. Rhino, AVTO1418, AVTO1314, Eureka, Roma VFN, MT56, Pinktop, Assila F1, Money-maker, AVTO0922 and AVTO1464 were the least affected by early blight; while AVTO1219, AVTO1701, ADV12021, ADV12076 and ADV1287A expressed low AUDPC values for late blight. Overall, AVTO1315 was the best yielder (30.8 metric tonnes ha-1), followed by AVTO0301 (29.0 t ha-1) and Nouvella F1 (26.1 t ha-1). Among the tomato genotypes evaluated, we recommend AVTO1701, AVTO0922, AVTO1464, AVTO0301 AVTO1315, AVTO1219, Pruna, Vega, ADV1287A and MT56 for the national performance trials.