Pepper wilt disease intensity was assessed on-farm in Bako Tibbe and Nonno districts of West Shewa Zone, Ethiopia during the main cropping season of October 2012. The wilt causing pathogens were identified from 50 diseased samples collected from the two districts. Of the 120 hot pepper fields surveyed, 116 fields were found to be infected with wilt disease. The overall percent prevalence and incidence of wilt disease was 96.7 and 86.4%, respectively. Identification and pathogenicity tests revealed that Ralstonia solanacearum and four fungal wilt pathogens (Rhizoctonia solani, Fusarium spp., Phytophthora spp. and Verticillium spp.) were detected in the surveyed fields. The percentage of occurrence of Rhizoctonia solani, Fusarium spp., Phytophthora spp. and Verticillium spp. were 45.0, 17.48, 12.59 and 11.89%, respectively; whereas, the frequency of R. solanacearum was 100%. Wilt disease in pepper in these two districts was caused by more than one wilt causing pathogen, thus management strategies should focus on these complex pathogens.

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Wheat stem rust caused by Puccinia graminis f. sp. tritici is a disease that causes complete annihilation of wheat crops over wide areas during epidemic years. The highland of Ethiopia is considered as a hot spot area for the development of stem rust complex. Hence, this study was carried out to detect the virulence diversity of P. graminis f. sp. tritici in Southern Tigray. The findings of this paper were based on race analysis through inoculation of stem rust populations, isolation and multiplication of single-pustule of the pathogen and race determination by inoculating on stem rust differential hosts. The phenotypic characterization of P. graminis f. sp. tritici resulted in identification of 20 races from 32 isolates, which included the most prevalent races TTSNK, RRJJC and HRJJC with a frequency of 9.4% each and the most virulent races TTKSK and TTSSK each making 85% of Sr genes ineffective. Three important races (TTSSK, TTSNK and RRTTF) are new to the study area and the country (Ethiopia) as a whole putting a significant wheat proportion at risk. Among 20 wheat stem rust differential hosts, four were found effective for 75% and more of the races identified. Differential host carrying Sr24 was effective to all, while gene SrTmp was effective to 90% of the races followed by Sr17 and Sr31 each effective for 75%. In contrast, differential hosts carrying SrMcN, Sr9b, Sr9g and Sr10 were ineffective to 96.9, 93.8, 87.5 and 81.2% of the isolates tested, respectively. Thus, use of effective Sr genes such as Sr24 and SrTmp in single cultivar through gene pyramiding has paramount importance as the additive effects of several genes gives the cultivar a wider base  stem rust resistance along with periodic race survey.