Search Results (55)

The foliar pathogens of wheat, particularly Zymoseptoria tritici and Pyrenophora tritici-repentis, represent a significant threat to yield. We used a SEIR (Susceptible–Exposed–Infected–Removed) model to quantify epidemic dynamics based on different fungicide application strategies, focusing on the daily dynamic growth rate r(t) (net infection increase) and the removal rate γ(t) (loss infectious tissue) after BBCH 37. In Scenario A (treatment of seed with Systiva^®), the r(t) of Z. tritici was positive only during the early phase of the epidemic, followed by progressive suppression over time, while the r(t) for P. tritici-repentis remained negative throughout. Scenario B (seed treatment combined with foliar propiconazole) resulted in uniformly negative r(t) values for both pathogens, indicating stronger and sustained suppression. These findings highlight the practical utility of epidemic growth rate modeling for evaluating fungicide strategies and support integrated seed + foliar applications as a robust approach to disease management in wheat. Full article

Wheat is one of the world’s essential crops, and the presence of foliar diseases significantly affects both the yield and quality of wheat. Accurate identification of wheat leaf diseases is crucial. However, traditional segmentation models face challenges such as low segmentation accuracy, limiting their effectiveness in leaf disease control. To address these issues, this study proposes MSDP-SAM2-UNet, an efficient model for wheat leaf disease segmentation. Based on the SAM2-UNet network, we achieve multi-scale feature fusion through a dual-path multi-branch architecture, enhancing the model’s ability to capture global information and thereby improving segmentation performance. Additionally, we introduce an attention mechanism to strengthen residual connections, enabling the model to precisely distinguish targets from backgrounds and achieve greater robustness and higher segmentation accuracy. The experiments demonstrate MSDP-SAM2-UNet achieves outstanding performance across multiple metrics, including pixel accuracy (PA) of 94.02%, mean pixel accuracy (MPA) of 88.44%, mean intersection over union (MIoU) of 82.43%, frequency weighted intersection over union (FWIoU) of 90.73%, Dice coefficient of 81.76%, and precision of 81.63%. Compared to the SAM2-UNet, these metrics improved by 2.04%, 2.76%, 4.1%, 2.06%, 4.9%, and 3.6%, respectively. The results validate that MSDP-SAM2-UNet have tremendous segmentation performance and offer a novel perspective for wheat leaf disease segmentation. Full article

Wheat, a globally vital food crop, faces severe threats from numerous foliar diseases, which often infect agricultural fields, significantly compromising yield and quality. Rapid and accurate identification of the specific disease is crucial for ensuring food security. Although progress has been made in wheat foliar disease detection using RGB imaging and spectroscopy, most prior studies have focused on identifying the presence of a single disease, without considering the need to operationalize such methods, and it will be necessary to differentiate between multiple diseases. In this study, we systematically investigate the differentiation of three wheat foliar diseases (e.g., powdery mildew, stripe rust, and leaf rust) and evaluate feature selection strategies and machine learning models for disease identification. Based on field experiments conducted from 2017 to 2024 employing artificial inoculation, we established a standardized hyperspectral database of wheat foliar diseases classified by disease severity. Four feature selection methods were employed to extract spectral features prior to classification: continuous wavelet projection algorithm (CWPA), continuous wavelet analysis (CWA), successive projections algorithm (SPA), and Relief-F. The selected features (which are derived by CWPA, CWA, SPA, and Relief-F algorithm) were then used as predictors for three disease-identification machine learning models: random forest (RF), k-nearest neighbors (KNN), and naïve Bayes (BAYES). Results showed that CWPA outperformed other feature selection methods. The combination of CWPA and KNN for discriminating disease-infected (powdery mildew, stripe rust, leaf rust) and healthy leaves by using only two key features (i.e., 668 nm at wavelet scale 5 and 894 nm at wavelet scale 7), achieved an overall accuracy (OA) of 77% and a map-level image classification efficacy (MICE) of 0.63. This combination of feature selection and machine learning model provides an efficient and precise procedure for discriminating between multiple foliar diseases in agricultural fields, thus offering technical support for precision agriculture. Full article

To address the need for improved nutritional value of organically grown wheat, this study investigated the impact of silicon treatments (AdeSil, ZumSil) on yield, health status, and bioactive compound content in spring wheat cultivars. The 2019–2020 research evaluated different application variants: seed dressing, foliar sprays, and their combinations. Comprehensive seed dressing combined with two foliar treatments, (variant B) and two foliar treatments (variant C), significantly increased yield (by an average of 8.9% and 7.6% vs. control, respectively). These variants beneficially affected fungal disease resistance mainly in the stressful 2019; in optimal 2020, they showed no clear advantage over the control, which performed similarly or better. Seed dressing (variant D) increased total phenolic acids (PAs) content and antioxidant activity, with the spelt cv. Wirtas exhibiting the highest levels. Silicon treatments modified alkylresorcinols (ARs) content, but effects depended on the year, cultivar, and application variant, not always exceeding the control. Silicon treatments, especially when applied in combination (seed dressing and foliar application), can improve spring wheat yield and favorably modify PAs content, enhancing grain nutritional value. However, the plant response regarding health status and ARs content is strongly conditioned by cultivar specificity and the prevailing environmental conditions of the growing year. Full article

Leaf rust (LR) is a devastating foliar disease that impacts common wheat (Triticum aestivum L.) globally. For optimal disease protection, wheat cultivars should possess adult plant resistance (APR) to leaf rust. In the current study, the objective was to map quantitative trait loci (QTL) related to leaf rust resistance. This was achieved by using 193 recombinant inbred line (RIL) populations which were developed from the cross between N. Strampelli and Huixianhong. Four trials were conducted in China (three in Baoding, Hebei province, and one in Zhoukou, Henan province) to assesses the leaf rust response of the RILs and parental lines. The wheat 660K SNP array and additional SSR markers were used to genotype the RIL populations. Through inclusive composite interval mapping (ICIM), three QTL related to leaf rust (LR) resistance were detected. ICIM was also employed to reevaluate previously published data in order to identify QTL with pleiotropic effects. To determine the physical positions, the flanking sequences of all SNP probes were compared against the Chinese Spring wheat reference sequence through BLAST searches. Three leaf rust resistance loci, two on chromosome 2A and 5B, were contributed by N. Strampelli. QLr.hbau-2AL.1 was detected in three leaf rust environments with phenotypic variance explained (PVE of 12.2–17%); QLr.hbau-2AL.2 was detected in two environments with 12.5–13.2% of the PVE; and QLr.hbau-5BL was detected in all leaf rust environments with phenotypic variance explained (PVE) of 17.8–19.1%. QLr.hbau-5BL exhibited potentially pleiotropic responses to multiple diseases. The QTL and the associated flanking markers discovered in this study could prove valuable for purposes such as fine mapping, the exploration of candidate genes, and marker-assisted selection (MAS). Full article

Wheat pathogens pose a significant risk to global wheat production, with climate change further complicating disease dynamics. Effective management requires a combination of genetic resistance, cultural practices, and careful use of chemical controls. Ongoing research and adaptation to changing environmental conditions are crucial for sustaining wheat yields and food security. Based on selective academic literature retrieved from the Scopus database and analyzed by a bibliographic software such as the VOSviewer we discussed and focused on various aspects of current and future strategies for managing major wheat pathogens and diseases such as Tan spot, Septoria tritici blotch, Fusarium head blight, etc. Chemical management methods, such as the use of fungicides, can be effective but are not always preferred. Instead, agronomic practices like crop rotation and tillage play a significant role in managing wheat diseases by reducing both the incidence and severity of these diseases. Moreover, adopting resistance strategies is essential for effective disease management. Full article

Tan spot (Pyrenophora tritici-repentis) and stripe rust (Puccinia striiformis f. sp. tritici) are major foliar diseases of wheat, causing significant yield losses globally. This study evaluated the efficacy of fungicide seed treatments in managing these diseases during early growth stages under greenhouse, growth chamber, and field conditions in the Northern Great Plains. Winter and spring wheat cultivars were treated with pyraclostrobin or combinations of thiamethoxam, difenoconazole, mefenoxam, fludioxonil, and sedaxane, among others. Greenhouse and growth chamber plants were inoculated with the respective pathogens, while field trials relied on natural inoculum. Fungicide treatments significantly reduced stripe rust severity (up to 36%) (p ≤ 0.05) and moderately reduced tan spot severity during early growth stages (15–20%). Treated plants demonstrated a 30–40% improvement in plant vigor, and a 25–50% increase in winter survival. Additionally, grain yield in treated plots increased by 25–50% (p ≤ 0.05), with test weight and protein content improving by 10% and 15%, respectively. These findings demonstrate the potential of fungicide seed treatments as an integrated pest (or pathogen) management (IPM) strategy to enhance early foliar disease control and wheat productivity. Full article

Sclerotinia sclerotiorum is one of the fungi that cause plant diseases. It damages plants by secreting large amounts of oxalic acid and cell wall-degrading enzymes. To meet this challenge, we designed a new pH/enzyme dual-responsive nanopesticide Pro@ZnO@Pectin (PZP). This nanopesticide uses zinc oxide (ZnO) as a carrier of prochloraz (Pro) and is encapsulated with pectin. When encountering oxalic acid released by Sclerotinia sclerotiorum, the acidic environment promotes the decomposition of ZnO; at the same time, the pectinase produced by Sclerotinia sclerotiorum can also decompose the outer pectin layer of PZP, thereby promoting the effective release of the active ingredient. Experimental data showed that PZP was able to achieve an efficient release rate of 57.25% and 68.46% when pectinase was added or under acidic conditions, respectively. In addition, in vitro tests showed that the antifungal effect of PZP was comparable to that of the commercial Pro (Pro SC) on the market, and its efficacy was 1.40 times and 1.32 times that of the Pro original drug (Pro TC), respectively. Crucially, the application of PZP significantly alleviated the detrimental impacts of Pro on wheat development. Soil wetting experiments have proved that PZP primarily remained in the soil, thereby decreasing its likelihood of contaminating water sources and reducing potential risks to non-target organisms. Moreover, PZP improved the foliar wettability of Pro, lowering the contact angle to 75.06°. Residue analyses indicated that PZP did not elevate prochloraz residue levels in tomato fruits compared to conventional applications, indicating that the nanopesticide formulation does not lead to excessive pesticide buildup. In summary, the nanopesticide PZP shows great promise for effectively managing Sclerotinia sclerotiorum while minimizing environmental impact. Full article

Fungal diseases are a yield-limiting factor for wheat. Their management in organic production systems is one of the prevailing challenges because it must be based mainly on indirect measures through agricultural practices. Variety mixtures are one of these practices, a concept that has been demonstrated to improve several factors affecting yield. Recently, it has become a practice that enables sustainability in agriculture. Our research aim is to evaluate the capacity of this practice to control three fungal diseases (foliar and ear) on durum wheat. This study was conducted over two consecutive years (2019 and 2020) at two locations: a certified organic farm in the Benslimane region (2019) and the National School of Agriculture farm in Meknes (2020). Four durum wheat varieties (Isly, Tarek, Karim, and Nassira) were used to create the mixture. The parameters that were monitored were the disease severity, the grain yield, and its components. The analysis of variance for the three fungal diseases’ severity was significant. The variety that showed resistance to all diseases was the Isly variety, and the most susceptible variety was the Nassira variety. The resistance of the other varieties to the diseases was variable from one year to the other. The mixture showed average severity values. It allowed a reduction in the severity of leaf rust of 47% during the first year and 30% during the second year compared to the most susceptible variety (Nassira). In the case of HLB (helminthosporiosis leaf blight), it reduced the disease by 47% during the first year and 34% during the 2020 season. For ear disease, Fusarium head blight (FHB), the reduction was 68% during the year 2019 and 49% during 2020. The mixture also ensured yield stability between the two trial years (1.66 t ha⁻¹ and 1.54 t ha⁻¹). Full article

Wheat leaf rust, caused by Puccinia triticina, poses a growing threat to global wheat production, necessitating alternative strategies for effective disease management. This study investigated the potential of gamma-aminobutyric acid (GABA) to enhance resistance to leaf rust in two wheat cultivars: the susceptible Morocco and moderately resistant Sakha 94 cultivar. Our findings revealed that GABA significantly improved resistance in both cultivars to P. triticina, particularly in Morocco, by mitigating disease severity and reducing pustule density and size while extending both incubation and latent periods. This study assessed the effectiveness of two GABA application methods: plants received 1 mM GABA treatment, as a foliar spray, twenty-four hours prior to infection (pre-GABA), and plants received 1 mM GABA treatment both 24 h before and after infection (pre-/post-GABA), with the latter yielding significantly better results in reducing infection severity and improving plant resilience. Additionally, GABA application influenced stomatal behavior, promoting closure that may enhance resilience against leaf rust. GABA application on plants also modulated the production of reactive oxygen species (ROS). This led to a stronger oxidative burst in both susceptible and moderately resistant cultivars. GABA increased O₂^●− levels in guard cells and surrounding stomata, enhancing stomatal closure and the hypersensitive response. GABA enhanced the accumulation of soluble phenols and increased the activity of key antioxidant enzymes, catalase (CAT) and peroxidase (POX), which are vital for managing oxidative stress. To the best of our knowledge, this investigation represents the first report into the impact of GABA on wheat leaf rust disease. Full article

Leaf rust (caused by Puccinia triticina Erikss., Pt) is a severe foliar disease of cultivated wheat worldwide. Severe development of the disease results in significant losses in seed yield and quality. Growing immune varieties is the most rational method for Pt control in terms of effectiveness and ecological safety. However, the gene pool of cultivated wheat is very narrow for seedling Pt effective resistance genes, which hampers breeding for this trait. One of the well-known methods to broaden genetic diversity for resistance is the introgression of highly effective genes from wild relatives into the genomes of cultivated wheat. The Aegilops L. species have been proven to be perfectly suited for this purpose. No gene for Pt resistance has been transferred to wheat from Aegilops biuncialis Vis. (Lorent’s goatgrass) up to now. Previously, we selected eight accessions of the species from the VIR (N.I. Vavilov All-Russian Institute of Plant Genetic Resources) genebank that showed a perfect level of resistance to leaf rust. In this research, we studied the genetic control of resistance using hybridological, phytopathological, and molecular analyses. According to the F₁–F₃ hybrid evaluation results, each accession possesses one dominant gene for Pt resistance, and genes in different accessions are allelic or very tightly linked. Phytopathological test clone analysis showed that this gene is not identical to Lr9, Lr19, Lr24, Lr39, and Lr47, which are effective against Pt populations in some areas of Russia. This conclusion was partially supported by the results of the identification of DNA markers specific to these genes in bread wheat. Thus, we identified one dominant gene (temporarily symbolized as LrBi1) for effective seedling Pt resistance; it is recommended for introgression to cultivated wheat via interspecific hybridization. Full article

Septoria leaf blotch (SLB), caused by Zymoseptoria tritici, is one of the most important foliar diseases of wheat. The management of this disease is assisted by selecting a sowing time and seeding density that is less favorable to the pathogen. The aim of this research was to evaluate the severity of SLB on winter wheat cv. ‘Etana’ sown at three different sowing times and three seed rates. The severity assessments were performed on the upper two leaves three times during the growth stages using the phenological growth stage key developed by the Biologische Bundesanstalt, Bundessortenamt, and Chemical industry (BBCH), namely stages 37–41, 59–65, and 75. The area under the disease progress curve (AUDPC) was evaluated in each plot. In 2022, seed rates showed significant differences (p = 0.0047), while sowing times did not show significant differences. In contrast, both seed rate and sowing time showed significant effects in 2021 (p = 0.0004 for sowing time and p < 0.0001 for seed rate). During the 2021 growth stage BBCH 75, late sowing times exhibited a significant reduction in SLB on the first leaf. The reduction ranged from 47.0% to 52.6% compared to the optimal sowing time, and from 59.2% to 66.2% compared to the early sowing time. At optimal sowing times (between 11 September and 25 September), seed rates of 400 and 450 seeds/m² resulted in a low SLB. At late sowing times in 2022, a lower SLB (43.2% compared to the early sowing time) was obtained from seed rates of 400 seeds/m². No significant interaction was observed between sowing time and seed rate across both study years. In the absence of interaction, the effects of sowing time and seed rate on SLB severity were independent and not additive. In 2022, the highest values of AUDPC were recorded for the early sowing time and the highest seed rate. Increasing the seed rate (450 seeds m⁻²) gave higher AUDPC at early sowing time with significant differences compared to other seed rates at optimal or late sowing times. In conclusion, our findings highlight the significant influence of sowing time and seed rate on SLB severity in winter wheat. Understanding these factors can inform agricultural practices to better manage SLB. Future research should explore additional agronomic practices and environmental factors to develop comprehensive strategies for SLB management. Full article

Fungicides play a crucial role in conventional agriculture for disease control, but their prolonged use raises health and environmental concerns. Fusarium culmorum (F. culmorum), a major wheat pathogen causing Fusarium head blight (FHB) and Fusarium crown rot (FCR), poses significant mycotoxigenic threats. The application of natural plant extracts has been proven to fight against phytopathogenic fungi. This study aimed to a field experiment that was carried out at the Field Experimental Station of the Institute of Plant Protection—National Research Institute in Winna Góra, Poland, during the 2022/2023 season to evaluate the potential of Lamium album (L. album) flower extract as a foliar spray against mycotoxigenic fungi in two winter wheat varieties: Arkadia and Julius. The supercritical carbon dioxide extraction method (SC-CO₂) was employed to obtain the L. album flower extract. Ergosterol (ERG) and mycotoxin accumulation in the harvested wheat grains were analyzed using chromatography-based methods. The results demonstrated a notable reduction in ERG content in the field plots treated with L. album flower extract, from 26.07 µg/g (control group) to 8.91 µg/g (extract-treated group) for Arkadia and from 70.02 µg/g (control group) to 30.20 µg/g (extract-treated group) for Julius. The treatment with L. album reduced mycotoxin biosynthesis in both varieties, with deoxynivalenol (DON) and zearalenone (ZEN) production significantly decreased. Additionally, Arkadia exhibited greater resistance to Fusarium infection, and the antifungal effect of L. album was more pronounced than in the Julius variety, which proved to be more sensitive. In conclusion, L. album flower extract exhibited promising antifungal effects in field experiments to fight against F. culmorum in winter wheat varieties, suggesting a potential alternative to synthetic fungicides. However, as complete prevention of mycotoxin contamination was not achieved, further research is warranted to optimize extract concentrations and conduct long-term analyses to consider this plant extract as a sustainable control agent. Full article

To reveal genetic diversity for effective resistance to five foliar diseases and toxic aluminum ions, the entire collection of wheat species from the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) originating from Ethiopia and Eritrea were studied regarding their traits. The collection contains 509 samples of four wheat species (Triticum aestivum—122 samples; T. aethiopicum—340 samples; T. polonicum—6 samples; and T. dicoccum—41 samples). The majority of accessions are new entries of landraces added to the Vavilov collection as a result of the Russian–Ethiopian expedition in 2012. Wheat seedlings were inoculated with causal agents of leaf rust (Pt), powdery mildew (Bgt), Septoria nodorum blotch (SNB), and dark-brown leaf spot blotch (HLB). The types of reaction and disease development were assessed to describe the levels of resistance. All samples of T. aethiopicum were also screened for seedling and adult resistance to Pt, Bgt, and yellow rust (Pst) under field conditions after double inoculation with the corresponding pathogens. To study tolerance to abiotic stress, seedlings were grown in a solution of Al³⁺ (185 µM, pH 4,0) and in water. The index of root length was used to characterize tolerance. Seedlings belonging to only two accessions out of those studied—k-68236 of T. aethiopicum and k-67397 of T. dicoccum—were resistant to Pt at 20 °C but susceptible at 25 °C. Specific molecular markers closely linked to the five genes for Pt resistance effective against populations of the pathogen from the northwestern region of Russia were not amplified in these two entries after PCR with corresponding primers. Four entries of T. dicoccum—k-18971, k-18975, k-19577, and k-67398—were highly resistant to Bgt. All samples under study were susceptible to HLB and SNB. Under field conditions, 15% of the T. aethiopicum samples were resistant to Pst, both at the seedling and the flag leaf stages, but all were susceptible to the other diseases under study. Among the evaluated samples, 20 entries of T. aestivum, 1 of T. polonicum (k-43765), and 2 of T. dicoccum (k-18971, k-67397) were tolerant to aluminum ions. The identified entries could be valuable sources for the breeding of T. aestivum and other wheats for resistance to biotic and abiotic stresses. Full article

Wheat leaf rust, caused by the obligate biotrophic fungus Puccinia triticina Eriks. (Pt), is one of the most common wheat foliar diseases that continuously threatens global wheat production. Currently, the approaches used to mitigate pathogen infestation include the application of fungicides and the deployment of resistance genes or cultivars. However, the continuous deployment of selected resistant varieties causes host selection pressures that drive Pt evolution and promote the incessant emergence of new virulent races, resulting in the demise of wheat-resistant cultivars after several years of planting. Intriguingly, diploid wheat accessions were found to confer haustorium formation-based resistance to leaf rust, which involves prehaustorial and posthaustorial resistance mechanisms. The prehaustorial resistance in the interaction between einkorn and wheat leaf rust is not influenced by specific races of the pathogen. The induced defense mechanism, known as systemic acquired resistance, also confers durable resistance against a wide array of pathogens. This review summarizes the host range, pathogenic profile, and evolutionary basis of Pt; the molecular basis underlying wheat–Pt interactions; the cloning and characterization of wheat leaf rust resistance genes; prehaustorial and posthaustorial resistance; systemic acquired resistance; and the role of reactive oxygen species. The interplay between climatic factors, genetic features, planting dates, and disease dynamics in imparting resistance is also discussed. Full article