Search Results (151)

The sustainable production of Dioscorea polystachya (Chinese yam) is severely compromised by a vicious cycle of excessive chemical dependency and complex biotic stresses including anthracnose, nematodes, thrips and other associated pests and diseases. Moreover, the efficacy of single biocontrol agents in field applications often proves unstable, and balancing the growth–defense trade-off remains challenging. To break these impasses, we established a novel “ZR Integrated Green Control System” (ZR-IGCS) by coupling an active plant immune inducer ZNC with a functional microbial agent Recharge. This system establishes a dual defense barrier, orchestrating internal immune activation with external micro-ecological regulation to engineer ecological synergy. Field trials demonstrated that the ZR-IGCS significantly accelerated seed tuber germination and seedling biomass accumulation. It established a spatiotemporal complementary defense network, exhibiting excellent integrated pest and disease control efficacy. The system maintained over 60% efficacy against foliar diseases such as anthracnose and brown spot, while enhancing the control of soil-borne diseases like wilt and root-lesion nematodes by more than 60% and 30%, respectively. It also achieved ~48% specific control of thrips. Crucially, ZR-IGCS alleviated the growth–defense conflict, significantly delaying plant senescence and synchronously optimizing yield structure for aerial beans and underground tubers. This synergy increased the proportion of high-quality yam beans, yielded a 51.66% surge in high-quality tubers, and improved total economic benefits by ~30%. The combined system successfully bridges the gap between laboratory potential and field stability for yam production, offering a robust and sustainable strategy to mitigate continuous cropping obstacles and reduce chemical inputs. Full article

Moringa oleifera seed cake is the byproduct of moringa oil extraction and the most valuable source of 4-(α-L-rhamnosyloxy)benzyl glucosinolate (glucomoringin; GMG), the precursor of 4-(α-L-rhamnosyloxy)benzyl isothiocyanate (moringin; GMG+M). The vascular fungus Fusarium oxysporum f. sp. lycopersici (FOL) is an important soil-borne pathogen of tomato in cultivated areas worldwide. Coating seeds with phytochemicals has been reported to prevent seed transmission and control seedling infection. In this work, GMG was extracted and purified from moringa seed cake on the multigram scale, and GMG+M solutions obtained through controlled hydrolysis of the precursor with commercial myrosinase were evaluated against the pathogen both in vitro and in planta. FOL conidia germination and mycelial growth were significantly inhibited by GMG+M solutions in the range 1–1000 µM, in a dose-dependent manner, compared to GMG and control treatments, which did not differ significantly. Interestingly, the coating of tomato var. crovarese seeds with GMG or GMG+M (100 µM) resulted in equally effective reduction (70%) of the disease severity in post-emergence, suggesting a plant-mediated mechanism underlying the efficacy of the intact glucosinolate. Seed coating with both phytochemicals triggered polyphenol oxidase (PPO) activity in five-day-old tomato sprouted rootlets. This study highlighted the potential biotechnological value of M. oleifera seedcake for the development of a sustainable biopesticide. Full article

Potato (Solanum tuberosum L.) is an important staple and food security crop to many communities in the world. However, potato production and quality is greatly constrained by bacterial wilt, a disease caused by a soil-borne pathogen, Ralstonia solanacearum. Ralstonia solanacearum can be managed through clean seed systems and therefore laboratory testing is a pre-requisite for seed certification to confirm the absence of the pathogen in potato seeds before planting. Molecular diagnostics is the gold standard for detection of R. solanacearum in potato seeds. However, the extraction of genomic DNA from R. solanacearum for molecular diagnostics is complex, tedious, lengthy and/or costly procedure. A simple, rapid and reliable DNA extraction protocol is required for use in routine molecular diagnosis of R. solanacearum, a high-risk quarantine pathogen. In this study, we developed a simple and rapid protocol for extracting genomic DNA from symptomatic and asymptomatic potato tubers infected with R. solanacearum and verified its efficiency for the detection and molecular characterization of the pathogen. The protocol was developed from the evaluation of distilled water, Tris-EDTA (TE) and Tris buffer as a base solution for tissue maceration. The DNA quantity and integrity was determined using the NanoDrop 2000C spectrophotometer and agarose gel electrophoresis, respectively. Both hot and cold solutions produced intact high molecular weight genomic DNA of sufficient yield and purity for molecular-based applications. The detection and determination of phylotypes of R. solanacearum, based on conventional and multiplex polymerase chain reaction (PCR), amplified the expected 280 and 372 bp amplicons, respectively, confirming that the quantity and quality of the extracted pathogen genomic DNA was sufficient for molecular diagnostic applications. The sequencing of the amplified products of the endoglucanase gene produced good quality sequences, which confirmed the R. solanacearum isolates to be members of phylotype II sequevar 1. This protocol is a simple, fast and reliable tool for the extraction of sufficient genomic DNA with high quality, directly from R. solancearum-infected potato tubers for PCR and sequencing applications. Its simplicity and throughput make it valuable for use in routine diagnostics and can be adopted by certification programs to ensure distribution of clean potato seeds to farmers. Full article

Naturally abundant endophytes colonize plants internally without causing harm to their host plants. Endophytes are likely to occupy the same ecological niches as phytopathogens and thus have a high potential to be effective biological control agents. Their demonstrated ability to suppress more than one plant pathogen suggests that they can offer a viable alternative to chemical fungicides and a strategy for decreasing the inoculum potential of soil-borne pathogens. Some biocontrol endophytes are also known to improve soil health and the overall health of plants. However, the results in greenhouse studies do not always translate to consistent field efficacy. In this study, the efficacy of three endophytic bacterial isolates (PRT (Bacillus subtilis), PSL (Bacillus amyloliquefaciens), and IMC8 (Bacillus thuringiesis) were evaluated against Phytophthora capsici in a field environment and compared with two commercial biological fungicides, Serenade^® (Bayer Crop Science, St Louis MO, USA) and Double Nickel^® (Certis Biologicals, Columbia, MO, USA), and water control. Plants were inoculated with the bacteria strains using seed treatment for early plant colonization before transplanting to a field infested with P. capsici. Treatments with commercial bio-fungicides followed label recommendations. Data on plant growth vigor, disease severity, number of fruits, fruit size, total yield per plant, and percent of diseased fruits displayed significant differences between the bacteria treatments. While PRT was the best treatment for most traits, followed by PSL on pepper, PSL and Double Nickel were the best treatments on tomatoes. IMC8 was best for plant vigor and larger fruit size, but with fewer fruits per plant on both crops. This study suggests bacterial isolates PRT, PSL, and IMC8 can provide additional products for growth promotion and P. capsici disease management in pepper and tomatoes. Full article

Soil-borne diseases have become increasingly serious due to continuous planting. Soil fumigation may be inadequate because of the persistence of soil-borne pathogens on ginger seed rhizome. A combined strategy of soil fumigation and seed rhizome disinfection would be necessary to achieve synergistic control. In this study, the approach of soil fumigation with chloropicrin (CP) coupled with seed rhizome disinfection (Copper, Cu) was first adopted to evaluate the synergistic effects on soil physicochemical properties, enzyme activities and microbial communities, and therefore reveal mechanisms for soil microecological health and crop yield promotion. The results showed the comprehensive strategy could reduce NO₃⁻-N content, and the activities of soil enzymes, while increased NH₄⁺-N content, EX-Cu, and OXI-Cu content, which were positively correlated with ginger yield but negatively correlated with soil-borne pathogens and plant mortality. On the other hand, there was a reduction in bacterial diversity and richness, which was positively correlated with the abundance of soil-borne pathogens. Moreover, some beneficial soil microorganisms’ relative abundance (such as Firmicutes, Actinobacteria, Bacillus, and Sphingomonas.) was increased. The strategy decreased the abundance of Fusarium spp. and Phytophthora spp. by 49.41–90.07% and 43.34–89.21%, respectively. Compared with other treatments, the combination decreased the ginger mortality by 5.70–57.02% and increased the growth of ginger plants and yield by 3.58–139.96%, and 13.11–399.74%, respectively. This study highlights a prospect to promote ginger growth and yield by blocking the transmission of primary infection pathogens in ginger cultivation and improving soil ecological environment. Full article

Cotton Verticillium wilt, caused by Verticillium dahliae, is a devastating soil-borne disease that severely limits global cotton production. While Myxococcus fulvus KS01 has demonstrated potent antagonistic activity and multi-functional biocontrol effects against V. dahliae, its practical application has been hindered by low myxospore yields and inconsistent efficacy in initial solid-state fermentation (SSF). This study aimed to optimize the SSF process for strain KS01 to maximize myxospore production and systematically evaluate its biocontrol efficacy against Verticillium wilt. Using a mixture of wheat straw and Protaetia brevitarsis frass (an agricultural byproduct) as the base substrate, we utilized single factor experiments and Response Surface Methodology (RSM) to optimize nutritional supplements and fermentation parameters. The optimized SSF process was determined as follows: a 3:1 (w/w) frass-to-straw ratio, supplemented with 3.08% potato starch and 1.05% yeast powder, with a 15.03% inoculum size, 65.05% moisture content, and an initial pH of 7.0, fermented at 30 °C for 6 days. Under these conditions, the myxospore concentration reached 6.61 × 10⁷ CFU/g, representing a 131.2-fold increase compared to unoptimized conditions (5.0 × 10⁵ CFU/g). Greenhouse pot trials showed that the optimized KS01 solid agent achieved a control efficacy of 71.9%. In field trials conducted in heavily infested soil, the agent maintained control efficacies of 71.2% at the budding stage and 54.5% at the bolling stage, significantly outperforming the commercial fungicide Benziothiazolinone (51.4% and 41.4%, respectively) and the sterile substrate control. Furthermore, application of the KS01 agent significantly promoted cotton growth, with seed cotton yield reaching 5380.0 kg/ha, equating to a 50.4% reduction in yield loss compared to the untreated control. Our results demonstrate that the valorization of P. brevitarsis frass through optimized SSF significantly enhances the production and field performance of M. fulvus KS01. This study provides a novel technical framework and a robust microbial resource for the sustainable management of Verticillium wilt in saline alkali cotton production systems. Full article

Here, we adopt an historical approach towards reviewing research since the 1970s on the seed-borne virus diseases of cool-season pulses caused by pea seed-borne mosaic virus (PSbMV) in Australia’s grain cropping regions. All relevant investigations concerning the principal cool-season pulse crops infected; field pea, lentil, faba bean, chickpea, and the minor ones, Lathyrus species, vetches and narbon bean, are covered. However, as the PSbMV field pea pathosystem is the most studied, this receives greatest emphasis. The review starts with brief background information, and by describing the disease symptoms caused and the advances in sample testing procedures. Next, findings from past PSbMV studies are covered in greater detail including transmission by aphids, contact and seeds; occurrence in crops and seed stocks; pathotypes and genetic diversity; host resistance; and phytosanitary, cultural and chemical control measures. What these studies found about PSbMV biology, epidemiology and control is emphasized by describing past glasshouse and field experimentation. Then, practical research outcomes identifying PSbMV’s epidemic drivers, forecasting its epidemics and devising an integrated disease management strategy are emphasized. Examples of images that illustrate past investigations and research outputs are provided. Finally, principal research achievements and priorities for future Australian PSbMV cool-season pulse research are highlighted. Full article

Temperate grain legumes, including faba bean, field pea, chickpea, lentil, and grass pea, are important food and forage crops in the cereal-based cropping system in the Nile Valley and Red Sea region countries. Despite their importance, local production remains insufficient, and the countries are forced to import to narrow the demand gaps. Emerging diseases, such as faba bean gall disease and several viruses (Chickpea chlorotic dwarf virus, Chickpea chlorotic stunt virus, Faba bean necrotic yellows virus, and Pea seed-borne mosaic virus), are on the rise due to climate variability, changes in farming systems such as monocropping, reduced crop rotations, limited knowledge about the pathogens, and absence of varieties with good levels of resistance. This review synthesizes research achievements in the region and identifies focus areas, primarily resistance breeding, characterization of pathogen populations, developing efficient screening techniques, investigations of mixed virus infections, advancement of pathogen diagnostic techniques, and developing agroecologically based disease management strategies to reduce economic impacts of new and re-emerging diseases. Moreover, research collaboration and information exchange among countries in the region are essential to mitigate the growing threat of emerging legume diseases. Full article

Brown spot, caused by the seedborne fungus Bipolaris oryzae, remains a major constraint in rice production. Here, we used in vitro and in vivo assays to evaluate the biocontrol potential of three Bacillus strains (Ba. cereus OQ725688.1, Ba. velezensis OP938696.1, and Ba. subtilis OP937353.1) against Bi. oryzae in two rice cultivars (“Rubelita” and “Predileta”). Ba. cereus showed the highest in vitro mycelial inhibition (≈95%), whereas Ba. velezensis was the most effective under greenhouse conditions, reducing disease severity by up to 60% and increasing seedling vigor by 51% compared with infected controls. “Predileta” showed the strongest response to bacterial treatment, maintaining severity scores below 2 even under high inoculum pressure. Functional assays confirmed that all strains displayed amylolytic, catalase, and phosphate-solubilizing activities, with Ba. velezensis uniquely expressing strong cellulase and protease activities. Genome analysis of Ba. velezensis OP938696.1 revealed multiple biosynthetic gene clusters for antifungal polyketides and lipopeptides. These integrated biochemical and genomic traits demonstrate the novelty and potential of this Neotropical strain as a multifunctional agent capable of suppressing Bi. oryzae while enhancing rice seedling performance. Incorporating such a native strain into seed and soil management offers a sustainable strategy for rice protection in Neotropical systems. Full article

Net form net blotch disease, caused by Pyrenophora teres f. teres (Ptt), is one of the most destructive barley diseases, resulting in severe yield and grain quality losses worldwide. The increasing prevalence of fungicide-resistant Ptt strains, driven by the pathogen’s high genetic variability, highlights the urgent need for sustainable and eco-friendly disease management strategies. The present study provides novel insights into the use of native seed-borne endophytic bacteria naturally associated with barley as biological control agents against Ptt. Two endophytic bacterial strains isolated from healthy barley seeds were identified based on 16S rRNA gene sequencing as Bacillus subtilis PX491551 and Stenotrophomonas rhizophila PX494419. Their biocontrol potential against Ptt was evaluated through in vitro, greenhouse, and field experiments. In the dual-culture assay, B. subtilis and S. rhizophila inhibited the mycelial growth of Pyrenophora teres f. teres by 64.34% and 50.14%, respectively. Under greenhouse conditions, B. subtilis and S. rhizophila significantly reduced disease severity at the seedling stage, with scores of 2.00 and 4.00, respectively, compared to 9.33 in the untreated control. Beyond disease suppression, both endophytic bacteria markedly enhanced the host’s defense system. S. rhizophila induced the highest accumulation of total soluble phenolics, while B. subtilis significantly increased flavonoid content and boosted higher activities of superoxide dismutase and phenylalanine ammonia-lyase. In contrast, S. rhizophila showed the strongest induction of ascorbate peroxidase activity. Notably, field application of both bacteria consistently reduced net blotch severity over two consecutive growing seasons (2023–2024 and 2024–2025) and considerably improved chlorophyll content, 1000-grain weight, and grain yield. Overall, this study demonstrates that native seed-derived endophytic bacteria not only suppress barley net blotch but also enhance host antioxidant and defense responses, highlighting their potential as effective and sustainable biological control agents for barley disease management. Full article

Dengue is a mosquito-borne viral disease transmitted by Aedes aegypti, the main vector in the Americas. The lack of effective antiviral treatments, limited vaccine coverage, and the increasing resistance of mosquitoes to conventional insecticides emphasize the need for alternative vector control strategies. Plant-derived larvicides represent a promising and eco-friendly approach. This study characterized the phytochemical profile of Persea americana Mill. (var. Lorena) and evaluated its larvicidal activity against Ae. aegypti (Rockefeller strain). The phytochemical profile was assessed through qualitative screening, UV-Vis spectrophotometry, and UHPLC analysis. Larvicidal activity was evaluated against third-instar larvae of Ae. aegypti (Rockefeller strain) and the median lethal concentration (LC₅₀) values were determined. Preliminary screening of ethanolic extracts revealed the presence of various secondary metabolites of pharmacological relevance, including alkaloids, coumarins, tannins, flavonoids, saponins, triterpenes/sterols, and quinones. UV-Vis spectra displayed distinct absorption patterns, with a prominent peak near 260 nm, consistent with the presence of aromatic compounds. UHPLC profiling revealed high chemical diversity across different plant parts, with 70, 98, 71, and 52 peaks (above 1 × 10⁵ intensity) detected in seed, flower, pulp, and leaf extracts, respectively. Larvicidal bioassays showed significant activity, particularly in the seed extract, with LC₅₀ values (µg/mL) of 3.8 (3.3–4.1) for seeds, 22.4 (21.8–23.9) for flowers, 23.0 (21.5–24.6) for pulp, and 29.7 (28.1–31.2) for leaves. This study highlights the larvicidal potential of ethanolic extracts from P. americana (var. Lorena), with the seed extract exhibiting the highest chemical diversity and bioactivity against Ae. aegypti larvae. The detection of key secondary metabolites, including flavonoids, alkaloids, and saponins, supports the development of an effective, plant-based larvicide for sustainable vector control strategies. Full article

Bambara groundnut is an underutilized legume with significant potential for enhancing nutrition and food security. However, limited knowledge of its seed systems hinders the development of targeted interventions. This study assessed the Bambara groundnut seed systems and seed quality in Ghana. A semi-structured questionnaire was used to examine seed production, conditioning, and saving practices, while 150 farmer-saved seed samples were evaluated for quality. The findings revealed that the seed system is predominantly informal, with 99% of farmers relying on their own saved seeds, which showed poor germination and emergence. About 54.4% sourced seeds from local markets, and 60.7% recycled seeds for five years or more. Seeds were stored unshelled in polypropylene bags in Tolon and shelled in the Kintampo South and Talensi Districts. Seed selection was primarily based on size (in Tolon) and visible absence of disease symptoms (in Kintampo South and Talensi). An incidence (7.6%) of seed-borne pathogens was recorded, with Aspergillus flavus (38.8%) and A. niger (16.6%) being most prevalent. Other pathogens included Macrophomina phaseolina (11.5%), Rhizopus spp. (6.5%), Curvularia lunata (5.3%), and A. fumigatus (1.9%). This study highlights the need to support community-based seed systems to improve farmers’ access to quality Bambara groundnut seed. Full article

Sclerotinia sclerotiorum (Lib.) de Bary, the causal agent of Sclerotinia stem rot (SSR) or white mold, is a soil-borne hemibiotrophic fungus that causes substantial soybean yield losses worldwide. This pathogen infects over 400 plant species and persists in soil for extended periods through melanized sclerotia, which can survive under extreme environmental conditions. The wide host range, environmental adaptability, and longevity of sclerotia make SSR a persistent challenge in soybean production. No single management tactic provides reliable control, which underscores the importance of integrated pest management (IPM). Cultural practices such as crop rotation with non-hosts, optimized row spacing, adjusted seeding rates, and targeted irrigation are fundamental to reducing inoculum and modifying canopy microclimates to slow infection. Although genetic resistance remains partial, the deployment of cultivars with stable performance across environments contributes to disease suppression, particularly when combined with fungicide applications. However, fungicide efficacy is inconsistent and limited due to environmental concerns and potential resistance. Advances in disease modeling have improved the timing and precision of chemical control, while biological control agents and RNA interference approaches offer promising future options. This review synthesizes current IPM strategies for SSR and explores emerging alternatives to support sustainable soybean production. Full article

Common bacterial blight (CBB) is a significant disease caused by the seed-borne pathogen Xanthomonas axonopodis pv. phaseoli (Xap), which devastates global bean production. This study evaluated the effects of Bacillus subtilis (Bst26), Lactobacillus plantarum (Lpkb10), their combination (Bst26 + Lpkb10), copper hydroxide (CH), and an untreated control on controlling CBB in three bean cultivars (Göynük, Saltan, and Tezgeldi). Disease incidence (CI), disease severity index (DSI), severity score (SC), area under disease progress curve (AUDPC), and disease control (DC), along with agronomic traits such as plant height, number of primary branches, root length, and fresh root weight, were recorded to assess both infection rates and plant health under each treatment. The findings revealed significant differences in DI, DSI, SC, AUDPC, and DC (p ≤ 0.01) among the bean cultivars for CBB. Among the cultivars, the Bst26 treatment and the combination of Bst26 and Lpkb10 showed the highest control effectiveness, with DI values of 33.11% and 33.46% in Saltan, 35.65% and 44.16% in Göynük, and 37.71% and 42.43% in Tezgeldi, respectively, at 21 days after inoculation (DAI). Bst26 alone and in combination with Lpkb10 effectively controlled CBB, with disease reduction of 56.80% and 46.49% in Göynük, 57.08% and 56.62% in Saltan, and 52.18% and 46.19% in Tezgeldi, respectively. Disease progression was highest in the untreated control, with DI ranging from 77.15% to 82.54% across Göynük, Saltan, and Tezgeldi cultivars. Significant differences (p ≤ 0.01) in plant height, root length, and root weight were observed among treatments and cultivars. Disease parameters were negatively correlated with plant growth traits, and multi-treatment analysis demonstrated that combining bacterial strains effectively reduced disease severity in susceptible cultivars, highlighting their potential for improved CBB management. Full article

Chickpea is a legume that grows in most parts of the world. It is negatively affected by abiotic and biotic factors like drought and fungal diseases, respectively. One of the most important soil-borne pathogens affecting chickpeas is Fusarium oxysporum f.sp. ciceris (Foc). Its population dynamics in the soil are affected by fluctuations in soil water content and host characteristics. For the last three decades, drought has been common in most areas of the world due to global warming. Drought stress decreases the quality and quantity of the chickpeas, particularly where soil-borne pathogens are the main stress factor for plants. The use of both drought-tolerant and disease-resistant cultivars may be the only option for cost-effective yield production. In this study, we screened the seeds of twelve chickpea genotypes WR-315, JG-62, C-104, JG-74, CPS-1, BG-212, ANNIGERI, CHAFFA, BG-215, UC-27, ILC-82, and K-850 for drought tolerance at increasing polyethylene glycol (PEG) concentrations (0-, 5-, 7.5-, 10-, 15-, 20-, 25-, 30- and 50%) to create drought stress conditions at different severities. The performances of genotypes that were previously tested in Foc resistance/susceptibility studies were assessed in terms of percentage of germination, radicle and hypocotyl length, germination energy, germination rate index, mean germination time, and vigor index in drought conditions. We determined the genotypes of C-104, CPS-1, and WR-315 as drought-susceptible, moderately drought-tolerant, and drought-tolerant, respectively. We then elucidated the stress levels of selected genotypes (20-day-old seedlings) at 0–15% PEG conditions via measuring proline and malondialdehyde (MDA) contents. Our findings showed that genotypes that were resistant to Foc also exhibited drought tolerance. The responses of chickpea genotypes infected with Foc under drought conditions are the next step to assess the combined stress on chickpea genotypes. Full article