Septoria tritici blotch (STB), caused by Zymoseptoria tritici, is a major disease of spring wheat in Ethiopia and worldwide. This study evaluated 45 spring wheat genotypes for adult plant resistance under natural infection at Holetta Agricultural Research Center during the 2022 and 2023 seasons. Disease was assessed using two methods: (i) visual estimation of disease severity (DS) as the percentage of leaf area with necrotic lesions bearing pycnidia; and (ii) pycnidial density within lesions scored on a 0–5 scale to classify resistance levels. Combined analysis of variance across years showed significant effects (P ≤ 0.01) of year, genotype, and genotype × year interaction. Genotype accounted for 42.81% of the total variance in mean disease severity (from early grain filling to 70% flag leaf infection with pycnidia-bearing necrosis) and 42.3% of the variance in AUDPC. Mean severity ranged from 46.46% to 73.49% in 2022 and 8.73% to 71.71% in 2023, while pycnidial density ranged from 2.23% to 35.7% and 1.21% to 45.47% in 2022 and 2023, respectively. Four reaction classes were identified: resistant (24.4% and 25.2%), moderately resistant (30.4% and 24.4%), moderately susceptible (22.2% and 20.7%), and susceptible (22.96% and 29.63%) in 2022 and 2023, respectively. ‘Catbird’ was the most susceptible cultivar, whereas ‘Gondo’ was the most resistant. Cluster analysis grouped the cultivars into eight clusters based on STB severity and AUDPC, including two clusters (six genotypes) with resistant responses. These clusters did not include the differential lines used to characterize Z. tritici races, suggesting that the underlying resistance genes require further molecular characterization. The resistant genotypes (Blouk #1, 6B662, Coulter, Erik, Gondo, and ETW17–115) were effective against pathotypes virulent to major Stb genes present in Veranopolis (Stb2, Stb6), Shafir (Stb6), and Estanzuela Federal (Stb7). Disease severity and AUDPC were negatively correlated with plant height, number of tillers per plant, spike length, number of seeds per spike, thousand kernel weights, and grain yield. Correspondence and principal component analyses identified three major groups among the 45 genotypes: resistant, high-yield potential, and susceptible. The resistant genotypes identified here provide valuable material for breeding programs targeting improved resistance to Z. tritici.
Septoria tritici blotch (STB), caused by Zymoseptoria tritici is among the most damaging foliar diseases of wheat, with yield losses reaching up to 82% under favorable conditions. To identify resistant sources, one hundred sixty bread wheat genotypes were screened at Dabat and Adet in northwestern Ethiopia during the 2023 and 2024 cropping seasons using an alpha lattice design with two replications. Disease severity was assessed at three growth stages and agronomic traits were recorded across environments. Combined analyses revealed that 17.5% of the tested genotypes exhibited resistant responses to STB, producing superior grain yield (≥ 4.5 t ha⁻¹) and thousand-kernel weight (≥ 45.41 g). Additionally, 52.5% of genotypes were moderately resistant, whereas 30% showed moderately susceptible reactions. Highly significant differences (P < 0.0001) were observed among genotypes for all studied traits, which were negatively correlated with disease parameters. The highest grain yield (5160.88 kg ha⁻¹) was obtained from genotype G81. This genotype also exhibited significantly lower disease severity at maturity (24.35%) and a significantly reduced AUDPC (968.6) compared with most of the tested genotypes. These findings highlight promising genetic resources for STB resistance, and further molecular studies such as QTL mapping and GWAS are recommended to identify resistance loci and accelerate their utilization in wheat breeding programs.
Abstract Sorghum (Sorghum bicolor (L.) Moench) is an important crop for food diversification and bioenergy programs in Indonesia due to its drought tolerance, adaptability to marginal lands, and high nutritional value. However, a previously unreported sorghum wilt disease in Indonesia is hindering its productivity. Morphological, molecular, and pathogenicity testing methods were used in this study to identify the cause of sorghum wilt in South Sulawesi. According to a field survey conducted in Maros Regency (2025), disease incidence ranged from 11 percent to 100 percent, and disease severity increased as the plants aged. The Super 1 variety showed a 27.72% incidence 21 days after planting (DAP), while Numbu showed 11.08%. At 56 days after planting (DAP), both varieties reached 100% incidence with severity reaching 91.7%. Pathogen isolation produced colonies with long-chained microconidia ranging in color from white to pale purple. Macroconidia are rarely septate (3–5), and no chlamydospores are present. Isolate FV-SR01 belongs to the Fusarium verticillioides clade, showing 99.8–100% similarity to reference strains, according to molecular analysis based on ITS and TEF1-α sequences. According to pathogenicity tests, seedlings exhibited wilting symptoms within ten to twelve days after inoculation; the disease severity index reached 3.6 (80–90% wilting), and the same isolate was successfully re-isolated, fulfilling Koch’s postulates. This study indicates that F. verticillioides is the primary cause of wilt disease in sorghum in South Sulawesi. This report is the first of its kind in Indonesia and will help strengthen the plant disease database and aid in the development of sustainable sorghum management strategies.
E. Djaya, T. Kuswinanti, A. Nasruddin et al.· Brazilian Journal of Biology· 0 citations
Background
: High-tunnel tomato cultivation technology is vital for year-round production during the rainy season and for enhancing income among smallholder farmers in north-west Ethiopia. However, its productivity and sustainability are adversely affected by Fusarium wilt (FW) disease. This study assessed the current status of FW epidemics, examined associated biophysical factors, and characterized
Fusarium oxysporum f. sp. lycopersici
(FOL) isolates during the 2024 main cropping season.
Methods
: A total of 75 high-tunnel technologies were inspected in four major tomato-producing districts within two zones. A logistic regression model was used to associate biophysical factors with disease incidence and severity.
Results
: All the surveyed high-tunnels were infected with FW, with incidence ranging from 43.6% (Libo Kemkem) to 60.5% (Dera), and severity from 41.4% to 58.3%. Disease incidence and severity were strongly correlated (P < 0.001) with district, age and leakiness of high-tunnels, seed type and source, plant and weed density, crop rotation, and irrigation method. Elevated incidence and severity (>50%) were notably associated with Dera district, gray soils, older and leaky high-tunnels, local and unknown seed varieties, informal seed exchange, high plant and weed density, fruit-setting stage, absence of crop rotation, and contact irrigation method. Pathogen isolation and characterization study identified eight morpho-culturally and pathogenically diverse FOL isolates.
Conclusion
: FW exhibits extensive distribution across high-tunnel technologies, driven by various biophysical factors and has diverse strains. Therefore, integrated management strategies, including cultural interventions and resistant varieties, are imperative for sustainable high-tunnel tomato production in the study area. Further research on temporal pathogen dynamics and molecular characterization of isolates is also recommended.
Yekoye Abebaw, G. Damessa, E. Adgo et al.· CABI Agriculture and Bioscie...· 0 citations
Wheat head blast (WHB), caused by the fungus
Pyricularia oryzae
pathotype Triticum (PoT), is a major disease affecting wheat in the Brazilian Cerrado region. This disease can significantly reduce grain yield because the environmental conditions in the tropical Cerrado biome favor PoT infection of wheat heads. This study aimed to evaluate the effect of the 2NS/AS translocation on WHB resistance and its impact on key yield components across multiple environments in the southern region of Minas Gerais state. As a result, eight wheat cultivars were evaluated under field conditions over five consecutive growing seasons (2021–2025). Disease incidence, grain yield (kg.ha
−1
), and thousand-kernel weight (TKW; g) were assessed. Significant differences (
p
≤ 0.05) were observed for all traits, with selective accuracies ranging from 0.79 to 0.99. Cultivars ORS1403 and TBIODuque exhibited the lowest disease incidence. TBIODuque, along with BRS404, ORSFeroz, and TBIOAton were the highest-yielding genotypes, while BRS404 and ORSFeroz showed the highest TKW. Furthermore, GGE biplot analysis confirmed that the patterns aligned with the average trends, with the TBIODuque cultivar standing out for its higher resistance and yield. Cultivars carrying the 2NS/2AS translocation showed lower average disease incidence to WHB. However, this translocation was not associated with increases in grain yield or TKW. This study provides valuable information to assist researchers in selecting wheat cultivars with partial WHB resistance for the tropical regions of the Brazilian Cerrado biome.
Ana Luiza Maria Serpa Andrade, A. Dorigan, F. Pereira et al.· European journal of plant pa...· 0 citations
Brown spot, caused by Bipolaris oryzae, is an important constraint to rice production under favourable disease conditions. This study evaluated the field efficacy of eight fungicides against brown spot and assessed disease severity among rice genotypes cultivated in farmers’ fields. A randomised complete block design with three replications was established at Rampur, Chitwan, using the susceptible cultivar Sankharika. Eight fungicide treatments and an untreated control were compared following three foliar applications at seven-day intervals. Disease severity and the area under the disease progress curve (AUDPC) were determined, and grain yield was correlated with AUDPC. A roving survey was also conducted at 21 locations in Chitwan and Nawalparasi districts. All fungicide treatments reduced final disease severity relative to the untreated control. Metalaxyl 8% + mancozeb 64% WP recorded the lowest mean AUDPC (436.85), followed by carbendazim (470.50) and hexaconazole (482.20). Hexaconazole recorded the lowest final disease severity (28.90%), whereas the untreated control recorded 45.20%. The association between grain yield and AUDPC was weak and not statistically significant (r = −0.031). The survey identified six genotypes, with maximum severity of 78% in Samba Mansuli and Sabitri and minimum severity of 26% in Kalo Basmati. These findings indicate differential fungicide performance and genotype responses under the evaluated field conditions and support further multilocation and multiseason validation.
Rajan Lamsal, Surakshya Ghimire, Gautam Thapa et al.· Asian Journal of Biology· 0 citations
Spot blotch, caused by Bipolaris sorokiniana, is one of the most destructive foliar diseases limiting wheat productivity, particularly under the warm and humid conditions of the Indo-Gangetic Plains. The present study was conducted during the 2024-25 Rabi season at the Norman E. Borlaug Crop Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, to evaluate the efficacy of different fungicides against spot blotch under field conditions. The experiment comprised eight fungicidal treatments, including triazoles, strobilurins, their combinations, and a contact fungicide, together with an untreated control. Two foliar sprays were applied at 10-day intervals after disease initiation. Disease severity was assessed as percentage disease intensity (PDI), while grain yield and the percentage increase in yield over the untreated control were recorded. Among the treatments, tebuconazole 50% + trifloxystrobin 25% (0.10%) was the most effective in reducing disease severity and increasing yield. The findings indicate that triazole-strobilurin combination fungicides provided better management of spot blotch, which may be associated with their complementary preventive and curative modes of action and systemic activity.
K. Kandpal, Deepshikha, Archana Kushwaha et al.· Microbiology Research Journa...· 0 citations