Wheat rust diseases pose one of the greatest threats to global food security, including subsistence farmers in Ethiopia. The fungal spores transmitting wheat rust are dispersed by wind and can remain infectious after dispersal over long distances. The emergence of new strains of wheat rust has exacerbated the risks of severe crop loss. We describe the construction and deployment of a near realtime early warning system (EWS) for two major wind-dispersed diseases of wheat crops in Ethiopia that combines existing environmental research infrastructures, newly developed tools and scientific expertise across multiple organisations in Ethiopia and the UK. The EWS encompasses a sophisticated framework that integrates field and mobile phone surveillance data, spore dispersal and disease environmental suitability forecasting, as well as communication to policy-makers, advisors and smallholder farmers. The system involves daily automated data flow between two continents during the wheat season in Ethiopia. The framework utilises expertise and environmental research infrastructures from within the cross-disciplinary spectrum of biology, agronomy, meteorology, computer science and telecommunications. The EWS successfully provided timely information to assist policy makers formulate decisions about allocation of limited stock of fungicide during the 2017 and 2018 wheat seasons. Wheat rust alerts and advisories were sent by short message service and reports to 10 000 development agents and approximately 275 000 smallholder farmers in Ethiopia who rely on wheat for subsistence and livelihood security. The framework represents one of the first advanced crop disease EWSs implemented in a developing country. It provides policy-makers, extension agents and farmers with timely, actionable information on priority diseases affecting a staple food crop. The framework together with the underpinning technologies are transferable to forecast wheat rusts in other regions and can be readily adapted for other wind-dispersed pests and disease of major agricultural crops.

Turcicum leaf blight (Exserohilum turcicum) (TLB) is a major disease affecting maize (Zea mays) in western Ethiopia. This study was designed to: assess the incidence and severity of TLB in major highland and mid-altitudes of maize growing agro-ecologies of Western Oromia, map the geographical distribution of the TLB disease in the study area, and evaluate the reaction of maize varieties under production to TLB. From each representative zone, 2 -12 districts were surveyed based on production of maize and 8 -73 fields each averaging 1 ha at the interval of 5 -10 km were assessed per zone. Such fields were randomly selected on both sides of the road. Each sampling point was marked with the global positioning system (GPS) using GPS receiver for altitude and co-ordinates. In each field, 9 m² areas were marked out in three randomly selected points in a diagonal form using meter tap. Ten stands of maize plant in the middle of each marked area were randomly selected and assessed for incidence and severity. Survey was conducted on 172 farmers' fields in 29 districts and five zones of major maize growing agro ecologies in western Oromia region of Ethiopia. Survey results revealed the prevalence of TLB across all the districts albeit at different levels. Mean TLB incidence ranged from 16.3% in Abay chomen to 96.67% in Wayu Tuka and mean percent severity index varied between 3.1% in Abay chomen and 57.5% in Lalo Assoabi district. The overall mean incidence and PSI were high (up to 74.1 and 34.7%, respectively) during the grain filling stage of maize compared to tasseling and silking stage of the crop. Most of maize varieties under production were found to be affected by TLB, while fertilizer application reduced the intensity of disease. Successive survey for TLB in all the maize producing areas across the country should be carried out to have a complete picture on the importance of the disease across geographic regions and agro ecologies, to identify sources of resistant genotypes and the pathotypes/available in Ethiopia, and to associate weather variables with the development of TLB.

Article InfoTurcicum leaf blight (Exserohilum turcicum), TLB, is a major disease affecting maize (Zea mays) in western Ethiopia. The aims of this study wereto: evaluate maize varieties and propiconazole spray frequencies on epidemics of TLB, determine optimum propiconazole (tilt 250 EC) spray frequency for integrated management of TLB, and assess the cost/benefit of using propiconazole for each spray frequency against TLB. The effects of maize varieties, fungicide frequencies and their interactions on TLB development were assessed in a field experiment during the 2017 main growing season at Ambo Plant Protection Research Centre (APPRC). The experiment involved three maize varieties(AMHQ-760,Wonchi and Jibat) and three fungicide (Tilt, propiconazole) frequencies arranged in a factorial setting in randomized complete block design with three replications. One unsprayed check for each hybrid varieties was included. TLB was initiated following artificial inoculation. Data were recorded on disease incidence and severity. Six time severity scores were used to calculate area under disease progress curve (AUDPC) and infection rate. Grain yield and yield components weremeasured after harvest. Finally correlation and economic analyses were carried out. Disease parameters varied markedly acrosstreatments, especially variety-fungicide combinations had a highly significant variation (p<0.01) in disease parameters. The highest terminal percent severity index (PSI) (86.7%), AUDPC value (2614.4 %-day) and disease progress rate (0.09339 units-day -1 ) were recorded on unsprayed variety AMHQ-760. On the other hand, the same variety had significantly lower disease level and gave the highest grain yield (9.424 t ha -1 ) when it was treated thrice with propiconazole. TLB resulted in grain yield losses of up to 62.4% on AMHQ-760. PSI, AUDPC, incidence and disease progress rate were negatively correlated with yield and yield components. The highest marginal benefit (ETB 63,089 ha -1 ), and marginal rate of return (ETB 14.53) were obtained from variety AMHQ-760 with thrice application of propiconazole. Based on current results, thrice propiconazoles pray were found effective to manage TLB even on susceptible maize variety. However, additional experiments should be carried out to verify the current results.

Wheat rusts are the key biological constraint to wheat production in Ethiopia—one of Africa’s largest wheat producing countries. The fungal diseases cause economic losses and threaten livelihoods of smallholder farmers. While it is known that wheat rust epidemics have occurred in Ethiopia, to date no systematic long-term analysis of past outbreaks has been available. We present results from one of the most comprehensive surveillance campaigns of wheat rusts in Africa. More than 13,000 fields have been surveyed during the last 13 years. Using a combination of spatial data-analysis and visualization, statistical tools, and empirical modelling, we identify trends in the distribution of wheat stem rust (Sr), stripe rust (Yr) and leaf rust (Lr). Results show very high infection levels (mean incidence for Yr: 44%; Sr: 34%; Lr: 18%). These recurrent rust outbreaks lead to substantial economic losses, which we estimate to be of the order of 10s of millions of US-D annually. On the widely adopted wheat variety, Digalu, there is a marked increase in disease prevalence following the incursion of new rust races into Ethiopia, which indicates a pronounced boom-and-bust cycle of major gene resistance. Using spatial analyses, we identify hotspots of disease risk for all three rusts, show a linear correlation between altitude and disease prevalence, and find a pronounced north-south trend in stem rust prevalence. Temporal analyses show a sigmoidal increase in disease levels during the wheat season and strong inter-annual variations. While a simple logistic curve performs satisfactorily in predicting stem rust in some years, it cannot account for the complex outbreak patterns in other years and fails to predict the occurrence of stripe and leaf rust. The empirical insights into wheat rust epidemiology in Ethiopia presented here provide a basis for improving future surveillance and to inform the development of mechanistic models to predict disease spread.

Estimates of heterosis for F1 hybrids over mid and better parent were computed for traits that showed significant differences between genotypes on analysis of variance. Heterosis for yield components and yield was studied using 8x8 half diallel cross in tomato (Solanum lycopersicum L.). The heterosis for yield was generally accompanied by heterosis for yield components. Heterosis for marketable fruit yield per plant ranged from (-63.4%) (P3xP8) to (33.8%) (P6xP8) and (-62.5%) (P3xP8) to (52.6%) (P5xP7), for mid parent and better parent respectively. Significant heterosis over better and mid-parent was observed for all the traits.  Best parent and Mid-parent heterosis (MPH) was highest  and in desirable direction for number of marketable fruit per plant  (29.3%; 29.2%)  in crosses ( P3xP6 for both ) and pericarp thickness  (46.3%; 57.6%) in crosses (P2xP6 and P4xP8), number of fruit cluster per plant (32.8%; 35.9%) in cross (P3xP6 for both), individual fruit weight (36.1%; 41.2%) in cross (P2xP8, P3xP5) and fruit diameter (28.4%; 28.3%) in cross (P3xP5; P2xP6), fruit length (23.07%; 20.4%)  in cross (P2xP6 for both). Out of 28 F1 crosses, positive and desirable heterosis by 10 crosses over better parent and 17 crosses over mid-parent were observed for total fruit density in tomato. An important heterosis both in heterobeltiosis and mid-parent was recorded in marketable fruit yield in ton per hectare. From all the crosses, seven crosses revealed positive from which three crosses are the most important P2xP7 (31%),  P3xP5 (20%) and P3xP6 (54%) in better parent heterosis. Similarly for mid-parent heterosis, only ten crosses out of 28 reveled positive while the rest 18 crosses showed the undesirable direction for marketable fruit yield indicating majority of the hybrids exhibited unfavorable heterotic response and only a few hybrids could be considered for selection.

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A study was conducted in a 8 × 8 half diallel cross set of tomato excluding reciprocals to estimate the general combining ability and specific combining ability for marketable fruit yield per plant (kg) and yield components, namely number of fruits per plant, individual fruit weight (g) fruit length (cm), fruit diameter (cm) and fruit thickness (cm) including some quality traits as TSS, pH and pericarp thickness. The experiment was conducted from December 2019 to March 2020 at Wollega University Experiment Field, Shambu and Hareto sites. Simple lattice design was used for field trial. Data from Fl generation and parents were analyzed using the Griffing Method II of Model I. Significant differences among genotypes were obtained for all the traits except for number of primary branches per plant. The effects of general combining ability (GCA) and specific combining ability (SCA) were highly significant indicating the presence of additive as well as non-additive gene effects except for fruit length and fruit diameter. The genotype P8 is selected a parent with the best general combining ability for marketable fruit yield per plant, individual fruit weight, fruit density, and fruit thickness. The tomato genotype P5×P7 followed by P3×P6 and P3×P7 were proved to be the best specific combiner for marketable fruit yield and number of fruits per plant.

Wheat stem rust caused by Puccinia graminis f.sp tritici is constant biotic constraint of wheat production across the world. Because of quick alteration of genetic makeup of wheat stem rust pathogen; monitoring shift in virulence within pathogen is crucial to avoid sudden occurrence of epidemics due race change. This study was to identify physiological races stem rust pathogen in Ethiopia during 2019 cropping season. Wheat stem rust samples were collected during 2019 main cropping season from major wheat growing areas of Oromia, Amhara, Tigray and Southern Nations Nationalities and Peoples regions of Ethiopia. Besides, samples were also collected from Afar region where wheat was grown by irrigation during off season. The samples where isolated on universally wheat stem rust susceptible line (McNair) for the sake of mono pustule isolation and multiplication to have sufficient spores. Each isolates where inoculated on twenty standard differential lines and each line was evaluated after fourteen days to determine the races. Eight stem rust races namely, TKKTF, TKTTF, TTTTF, TKKTT, TTKTT, TTRTF, TKPTF and TTKTF were identified from samples analyzed; TKKTF was identified from 175 (44.1%) stem rust isolates, while TTTTF was detected from 73 (18.4) samples analyzed. In addition, TKTTF was isolated from 70 (17.8%) samples; however, TTKTF, TTKTT, TTRTF, TKPTF and TKKTT were recorded from 48 (12.1%), 21 (5.3%), 4 (1%), 1 (0.25%) and 1 (0.25%) samples analyzed in the season. TTKTT races have 95% virulence spectra to stem rust