This study indicates that F. verticillioides is the primary cause of wilt disease in sorghum in South Sulawesi, 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.
Abstract
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.
Scanning electron micrographs of Sclerotium rolfsii paired with effective Trichoderma and Bacillus isolates showed swollen hyphae with cell-wall damage, providing clear evidence of antagonistic interactions caused by volatile compounds produced by B. amyloliquefaciens and T. harzianum.
A. A. Khan, V. Bhuvaneswari, P. Anisha et al.· Asian Research Journal of Ag...· 0 citations
Sweet cherry (Prunus avium L.) is an economically important stone fruit cultivated in the Shimla district of Himachal Pradesh (H.P.), India (31.1050°N, 77.1640°E), which accounts for over 90% of India's cherry production (~3,000–3,500 ha). During surveys in June–July 2023 and 2024, leaf spot disease was observed at seven localities (Narkanda, Kotgarh, Baghi, Matiana, Theog, Kumarsain, and Thanadhar). Disease incidence ranged from 48.0 to 92.9% and severity from 21.7 to 62.9%, affecting all major commercial varieties. Symptoms consisted of small, irregular dark-brown spots with concentric rings on both leaf surfaces, coalescing to cause necrosis and defoliation. Tissue pieces (2–4 mm) from necrotic leaf margins (20 leaves/orchard; 3–5 orchards/locality; 7 localities) were surface-sterilized with 1% NaOCl (1 min), rinsed in sterile water, and plated on PDA at 25°C for 7 days. The pathogen was recovered from 17 of 20 sampled leaves per orchard (isolation frequency 85%). Ten morphologically consistent isolates were obtained; three representative isolates (UHF-CHERRY-1, -2, -3) were selected based on morphology and sporulation, and deposited at MTCC, CSIR-IMTECH, Chandigarh (MTCC 14201, 14202, 14203, respectively). Colonies turned dark olive-green; diameter 52–58 mm after 7 days. Conidia were obclavate, light to dark brown, 23.37–25.64 × 9.06–11.35 µm (n = 50, sampled equally from all three isolates), with 1–4 longitudinal and 1–5 transverse septa, consistent with Alternaria alternata (Simmons 2007) . DNA was extracted (CTAB method) from all three isolates. ITS was amplified with ITS1/ITS4 (White et al. 1990); gpd and Alt-a1 with GPD1/GPD2 (Berbee et al. 1999) and AltaF1/AltaR1 (Asturias and Arilla 1995). GenBank: ITS — PV628437, OR230257, OR230237; gpd — PZ243383, PZ243385, PV648928; Alt-a1 — PZ243382, PZ243384, PV648929 (UHF-CHERRY-1, -2, -3). BLASTN showed ≥99% ITS and ≥98% gpd and Alt-a1 identity with A. alternata CBS 916.96 (type strain). Sequences were concatenated in BioEdit, aligned with MUSCLE, and a maximum likelihood tree constructed in MEGA 11 (1,000 replicates) with A. alternata CBS 916.96 (type strain), A. arborescens CBS 110.48, A. tenuissima CBS 117.44, A. infectoria CBS 232.96 (Woudenberg et al. 2015), and Stemphylium lycopersici CBS 122803 as outgroup. All three cherry isolates formed a strongly supported clade (bootstrap 100%), which was sister to A. alternata CBS 916.96 with 87% bootstrap support, distinct from A. arborescens, A. tenuissima, and A. infectoria clades . Pathogenicity was assessed for each isolate separately on five potted cherry seedlings (var. Black Heart) per isolate (15 inoculated; five controls with 0.01% Tween-20). Spore suspensions (5×105 conidia/ml) were sprayed on leaf surfaces; plants held at >90% RH, 25±1°C for 24 h then moved to a greenhouse at 25°C. The experiment was repeated twice with similar results. Leaf spots appeared 5–7 days post-inoculation; controls were asymptomatic and isolation from control plants yielded no growth. The fungus was re-isolated and confirmed morphologically and by ITS sequencing, fulfilling Koch's postulates. To our knowledge, this is the first report of A. alternata causing leaf spot on P. avium in India, a finding of significance given the high disease pressure recorded and the importance of cherry production in H.P. Accurate pathogen identification is essential for developing targeted management strategies in this region.
Cotton (Gossypium L.), known as “white gold,” is a globally important fiber and food crop. Pakistan is the world’s fourth largest cotton producer, with cultivation concentrated along the Indus River in of Punjab and Sindh. Cotton occupies 14% of Pakistan’s cultivated area (1). Fungal pathogens remain the most serious challenge for growers. In 2022–2023, similar disease symptoms were observed on upland cotton leaves at maturity in Multan and Rahimyar Khan districts of Southern Punjab. Symptoms begin as small circular lesions on the upper leaf surface, enlarging into necrotic dark-brown concentric rings up to 1.5 cm. Disease incidence was 20–25%. Forty diseased samples were collected, surface disinfected with 2% NaOCl for 1 min, rinsed thrice with sterile distilled water, and plated on Potato Dextrose Agar (PDA). Plates were incubated at 25 ± 2°C in dark, then purified. A total of 28 single-spored isolates were obtained for morphological characterization. Colonies on PDA were olivaceous brown to black after 7–8 days of incubation. Conidiophores were septate, light to olive golden brown with conidial scars. Conidia occurred singly or in short chains, obpyriform to obclavate. They began small, oval, brown with septa, later enlarging into longitudinal conidia with a beak. These features matched Alternaria alternata (Fr.) Keissler (2). Mycelia from 10-day-old cultures of four arbitrarily selected isolates (GHLS01, GHLS04, GHLS12, and GHLS17) were collected for DNA extraction using the Qiagen DNeasy Kit. PCR of ITS rDNA with ITS1/ITS4 (3) and GAPDH with gpd1/gpd2 (4) were performed. Sequences were deposited in GenBank (PV747746.1–PV747749.1 ITS; PV759324.1–PV759327.1 GAPDH). BLASTn analysis showed 99–100% sequence identity with isolates of A. alternata. Pathogenicity was confirmed by attached leaf assay. The experiment used 40-day-old Upland cotton plants in a greenhouse maintained at 25–30°C with ≥90% relative humidity, conducive for disease development. A total of 36 selected and tagged leaves from 12 plants were inoculated with the four isolates (GHLS01, GHLS04, GHLS12, and GHLS17). Mycelial plugs (5 mm) from 10-day-old PDA cultures were ground in sterile water to 10⁶ conidia/ml and applied to leaves by using spraying inoculation method. Control plants (n = 3) were untreated; the experiment was repeated twice. After 11–12 days, small brown spots expanded into concentric rings; controls remained asymptomatic. The pathogen was re-isolated and found morphologically and molecularly identical to A. alternata, thus satisfying Koch’s postulates. Alternaria alternata has previously been reported on upland cotton in New Mexico, (5) and Arizona (6). To our knowledge, this is the first report of A. alternata causing Alternaria leaf spot of cotton in Pakistan. This finding highlights a potential emerging threat to cotton production in southern Punjab and underscores the need for continued disease surveillance and management strategies.
Muhammad Umer Iqbal, Ahsan Abdullah, Nimra Asghar et al.· Plant Disease· 0 citations
Wheat is a major staple crop in Ethiopia, but its productivity is severely constrained by yellow rust (
Puccinia striiformis f.sp. tritici
), the most economically important wheat disease. A rain-fed field experiment was conducted in 2019 in the mid-highlands of East Gojjam (
Goncha Siso Enesie
district,
Enesie Qole Kebele
) to evaluate integrated management options combining fungicide application frequency and varietal resistance. Three bread wheat varieties (Tay, Picaflor, and Kubsa) with differing reactions to yellow rust were tested under four Tilt 250 EC (propiconazole) application frequencies (0, 1, 2, and 3) in a randomized complete block design with three replications. Terminal disease severity was recorded at 18.2% for Tay, 23.0% for Picaflor, and 44.0% for Kubsa under untreated conditions. When fungicides were applied three times at 10?day intervals, the highest percent disease control (PDC) achieved was 59.2% in Tay, 52.9% in Picaflor, and 71.9% in Kubsa. Yield and thousand kernel weight increased significantly (p<0.01) with three applications: up to 40.9% and 27.7% in moderately resistant Tay, 48.3% and 55.2% in moderately susceptible Picaflor, and 41.2% and 70.4% in highly susceptible Kubsa. These results demonstrate that combining host resistance with optimal fungicide frequency effectively manages yellow rust in bread wheat. Further research is needed to deploy eco-friendly management strategies.
Workineh Fenta· American Journal of Plant Bi...· 0 citations
Sorghum (Sorghum bicolor L.) is an important cereal crop grown in semi-arid, subtropical, tropical and temperate regions and it ranks fifth in worldwide cereal crop production. Rust of sorghum (Puccinia purpurea Cooke) is an important emerging disease in most sorghum growing areas of the world, which can increase susceptibility to other pathogens. Thus, there is a need to focus more on managing the disease. An attempt was made to manage the disease by integrating effective fungicides, botanicals, indigenous technical knowledge (ITKs) and bioagents under in vitro and in vivo conditions. In vitro studies revealed that among the different fungicides, botanicals, ITKs and bioagents tested, tebuconazole 50 % + trifloxystrobin 25 % and hexaconazole 5 % EC recorded 100 % uredospore germination inhibition. Among the botanicals, turmeric extract at 25 %, neem extracts at 50 % (78.39 %) while panchagavya (52.07 %) and combination of Trichoderma harzianum (5 g/L) and Pseudomonas fluorescens (5 g/L) (82.91 %) which recorded highest mean per cent inhibition of uredospore germination irrespective of concentration tested. Among 11 integrated spray schedules evaluated in a field study at the Main Agricultural Research Station (MARS), Dharwad during rabi seasons of 2021 and 2022, tebuconazole 50 % + trifloxystrobin 25 % at 0.05 % was significantly superior spray schedule. It recorded the lowest per cent disease index (PDI) of about 16.01 with highest grain yield (16.25 q/ha) and cost-benefit ratio (B:C ratio) of 1.87 followed by hexaconazole 5 % EC at 0.1 % (18.84 PDI; 15.76 q/ha). However, the highest PDI (92.50), lowest grain yield (9.63 q/ha) and B:C ratio (1.17) was recorded in the unsprayed control. The findings of this study highlight the potential of integrated disease management approaches combining chemical, biological and botanical components to achieve sustainable and economically viable control of sorghum rust and enhance productivity under semi-arid agro-ecological conditions.
G. G. R. Vishwas, K. B. Yadahalli, D. Gireesha et al.· Plant Science Today· 0 citations
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.
