In August 2025, soybean (Glycine max) plants with red perithecia and interveinal chlorosis of the foliage consistent with red crown rot (RCR), caused by Calonectria ilicicola were observed at very low incidence and severity in a commercial field in northern Columbia County, Wisconsin. Symptomatic plants were submitted to the Plant Disease Diagnostics Clinic and Field Crops Pathology Lab at the University of Wisconsin-Madison for confirmation of RCR. Stems were cleaned in water and disinfested in a 0.825% NaOCl solution for 1.5 minutes, rinsed in sterile deionized water for 5 minutes, disinfested in 70% ethanol for 1 minute then rinsed in sterile deionized water. Disinfested stem pieces were blotted onto sterile filter paper and 10 perithecia were picked directly from a stem and placed into a 1.5 ml microcentrifuge tube containing 400 µl of sterile deionized water and ground with a sterile Kontes pestle. Two hundred microliters of the suspension was spread across Petri-plates containing water agar with a sterile cell spreader. Plates were incubated at room temperature in the laminar flow hood for 1.5 hrs before examination under a dissecting scope. Single ascospores were transferred to fresh Petri-plates of PDA amended with antibiotics, as above. After 5 days, fungal colonies with white to light yellow aerial hyphae, later turning reddish, were observed growing on the PDA. Cultures derived from single ascospores were grown in potato dextrose broth to obtain mycelia for DNA extraction. DNA was extracted using a FastDNA Spin Kit (MP Biomedicals, Santa Ana, CA). PCR and DNA sequencing were performed using primers ITS5 and ITS4 (White et al., 1990) to amplify portions of the internal transcribed spacer region of rDNA. Primers T1 (O’Donnell and Cignelik, 1997) and Bt2b (Glass and Donaldson, 1995) were used to amplify a fragment of the β-tubulin gene. Amplicons were sent for Sanger sequencing (Functional Biosciences, Madison, WI). Sequences were submitted to NCBI GenBank (accession numbers PX872521 for ITS and PX935143 for β-tubulin). DNA sequences showed 99.7 to100% identity to C. ilicicola for both ITS and β-tubulin genes (GenBank accession numbers MN245059 and MK189210, respectively). To fulfill Koch’s postulates, plugs from an actively growing culture of C. ilicicola isolate RCR4 were used to infest millet grain in Erlenmeyer flasks. After 3 weeks, the infested millet grain was used in controlled inoculation experiments where six seeds from three soybean cultivars (Dwight, Williams 82 and Sauk) were planted into 4 replicate, 12 oz Styrofoam cups containing infested potting mix or non-infested potting mix (non-treated controls). Plants were maintained in a grow room under grow lights (14 h light at 18℃/ 10 h dark at 16℃). After 21 days, the plants were removed from the cups, the roots were cleaned and evaluated. Inoculated plants exhibited symptoms typical of RCR infection with red/blackish discoloration at the base of the stems, and extensive root rot (Bish et al. 2025). Calonectria ilicicola was re-isolated from symptomatic plants and identified by DNA sequencing (GenBank accession numbers PX872746 (ITS) and PX935144 (β-tubulin). No symptoms of disease and no pathogens were identified on non-treated control plants. The pathogenicity experiment was repeated with similar results. Red crown rot has been confirmed in several Midwest states (Kleczewski et al., 2023). Additional research is needed to fully understand its distribution and to develop effective disease management strategies.

Sudden death syndrome (SDS), caused by Fusarium virguliforme, is a major yield-limiting disease of soybean in the United States and Canada. Field trials in 2020 and 2021 across 13 U.S. states and Ontario, Canada, evaluated two SDS-targeted seed treatments and soybean cultivars: one susceptible (S) and one moderately resistant (MR) to SDS. Treatments included a base (prothioconazole + metalaxyl + penflufen, metalaxyl, and imidacloprid), base + fluopyram, and base + pydiflumetofen. Data collection included root rot ratings, SDS foliar symptoms, and yield. Under high SDS pressure (foliar disease index [FDX] ≥ 10), both SDS-targeted seed treatments and MR cultivars significantly reduced foliar symptoms (71 to 80%) compared with the base seed treatment and susceptible cultivars. Although 2020 and 2021 were not epidemic years for SDS, consistent reductions in SDS were observed. In the absence of disease, S cultivars produced greater yield than MR, but under high SDS and low soybean cyst nematode (SCN) pressure (<2,000/100 cm3 of soil), the MR cultivars produced greater yield than the S cultivars. Only the base + pydiflumetofen treatment maintained greater yield in the absence of SDS. When SDS pressure was high (FDX ≥ 10), both SDS-targeted treatments had 7.0 to 9.0% more yield than the base. Under combined high SDS and SCN pressure (≥2,000/100 cm3 of soil), only base + fluopyram preserved yield more than the base treatment. These results provide valuable insights for future SDS management through cultivar selection and seed treatments.

Sclerotinia stem rot (SSR) is a major soybean disease caused by the fungus Sclerotinia sclerotiorum and can reduce both soybean yield and quality. This study evaluated the effectiveness of Coniothyrium minitans, a mycoparasite of S. sclerotiorum formulated as the commercial product Contans®, applied at label-recommended rates ranging from 1.12 to 4.48 kg ha -1 following label-permitted timing recommendations, with sequential applications at planting and one month after planting across two soil types in Wisconsin. Although treatment effects were not statistically significant, numerical differences were observed that warrant further investigation. Higher application rates at planting may reduce SSR incidence and help preserve yield in the low organic matter sandy soils at Hancock, while providing partial disease suppression and moderate yield benefits in the high organic matter silt-loam soils at Arlington. The limited efficacy observed in this study may be attributed to the timing of applications, which, likely provided insufficient time for sclerotial colonization prior to the soybean crop being susceptible to infection by S. sclerotiorum. Consequently, extending the interval between application and planting may be necessary to achieve effective disease suppression. Adjusting application timing, such as in the fall, may improve efficacy by allowing greater sclerotial degradation prior to planting. Collectively, these findings highlight the need to further refine label recommendations to improve the reliability and consistency of C. minitans based SSR management.

Neurexin cell-adhesion molecules regulate synapse development and function by recruiting synaptic components. Here, we uncover a mechanism for presynaptic assembly that precedes neurexin recruitment, mediated by interactions between cytosolic proteins and membrane phospholipids. Developmental imaging in C. elegans reveals that the intracellular active zone protein SYD-1 accumulates at nascent presynapses prior to its binding partner neurexin. Combining molecular dynamics simulations to model intrinsic interactions between SYD-1 and lipid bilayers with biochemical and in vivo validation of these predictions, we find that PIP2-interacting residues in the SYD-1 C2 domain are required for active zone assembly. Genetic perturbation of a PIP2-generating enzyme disrupts synaptic SYD-1 accumulation, while the PIP2-interacting domain of mammalian RIM1 can compensate for the SYD-1 C2 domain, suggesting functional homology between these proteins. Finally, we propose that the evolutionarily conserved γ-neurexin isoform represents a minimal neurexin sequence that stabilizes nascent presynaptic assemblies, potentially a core function of this isoform.

Sclerotinia spp. are globally distributed phytopathogens responsible for economically significant diseases in a wide range of host plants, including soybean, sunflower, canola, lettuce, cabbage, and carrot. The long-term survival of the overwintering structures, sclerotia, in soil coupled with the lack of completely resistant cultivars, threatens crop health and yield stability. Disease management generally relies on cultural and chemical practices that may not be consistently effective in all cropping systems and can raise environmental concerns. Microbe-microbe interactions, such as long-recognized between Coniothyrium minitans and Sclerotinia spp. are gaining renewed attention as a promising tool to manage Sclerotinia-induced diseases, offering environmentally friendly and often durable alternatives. Despite its importance, limited attention has been given to the topic in existing literature. This review focuses on C. minitans, from its biology to field-level deployment. Its antagonistic activity relies on mycoparasitism and antibiosis, both of which are influenced by environmental, biological, field, and chemical factors. Commercialization and deployment of C. minitans-based biocontrol products faced several hurdles before widespread adoption. Contans®, a commercial product, is recommended for soil application at harvest or approximately eight weeks prior to planting, or as a foliar spray during or shortly before conditions become conducive for disease development. Numerous greenhouse and field trials provide evidence of effective disease management in various crops using C. minitans, supporting its integration in disease management practices. This comprehensive review can be helpful for researchers, Extension agents, and farmers seeking information on effective and sustainable alternatives for managing Sclerotinia-induced diseases across diverse cropping systems.

Sudden death syndrome (SDS), caused primarily by Fusarium virguliforme, can result in significant yield losses in soybean in the United States. Fluopyram is a seed treatment used for SDS management; however, its efficacy is not consistent. Little is known about how seed treatments are affected by the application of fertilizers. Field trials were conducted in Iowa from 2021 to 2023 to evaluate a nontreated control (NTC), a base (Allegiance FL + Stamina + Systiva XS Xemium brand + Poncho 600 + Flo Rite 1706 + Color Coat) seed treatment, and a base combined with various nanofertilizers (NanoStress, NanoPhos, NanoK, and NanoN, each at 292 ml/ha [4 fl. oz./acre]) with and without fluopyram (0.15 mg/seed). Combined analysis across 3 years revealed that base + fluopyram + NanoN resulted in a significantly lower foliar disease index (FDX) than the base, whereas base + fluopyram + NanoK and base + fluopyram + NanoPhos resulted in significantly more yield than the NTC. Other field trials were conducted in Iowa and Wisconsin during 2022 and 2023 to compare the effects of base, base combined with NanoStress + NanoN, 168 kg/ha N, fluopyram (0.15 mg/seed), fluopyram + NanoStress + NanoN, and fluopyram + 168 kg/ha N. The results showed significant effects on FDX and yield. Base + fluopyram + 168 kg/ha N significantly reduced FDX and increased yield as compared with the base treatment. These findings suggest that nanofertilizers and nitrogen fertilizers may enhance the performance of fluopyram, but further research is needed to explore how fertility influences host-pathogen interactions.Copyright (c) 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Globally, Fusarium head blight (FHB) is an economically important disease of wheat. Although several studies have compared disease levels of wheat produced using organic versus conventional management, few studies on FHB have considered specific organic management practices and how integrated management techniques best apply in these systems. Trials in Wisconsin and Indiana were designed to evaluate the management techniques currently available to organic farmers for their efficacy in reducing FHB and deoxynivalenol (DON) content while balancing yield and test weight. The practices evaluated included the use of a moderately resistant cultivar and the application of Organic Materials Review Institute-listed foliar fungicides. In both trial locations, Harpoon, the moderately resistant cultivar, significantly reduced the FHB index, FHB severity, and DON level compared with Kaskaskia, the susceptible cultivar (P < 0.05). In Wisconsin, Harpoon also significantly reduced the FHB incidence and foliar disease severity while providing increased yield protection (P < 0.01). Fungicide treatment did not significantly affect the FHB index, DON level, or yield in either location (P > 0.05). In Indiana, Reynoutria sachalinensis 12.0% (formulated as Pacesetter WS) significantly reduced the FHB incidence in the susceptible wheat cultivar (P < 0.05). Additional research is needed to evaluate treatments under higher disease pressure.

Sclerotinia stem rot (SSR) is an economically important disease of soybean, especially in the Great Lakes region of the United States. Few studies on SSR have considered organic management practices and how integrated management techniques best apply in these systems. Trials in Wisconsin and Indiana aimed to evaluate management techniques available to organic farmers for their efficacy in SSR control while preserving yield. The practices evaluated included genetically resistant cultivars, tillage techniques, and the application of Organic Materials Review Institute (OMRI)-listed foliar fungicides. The resistant cultivar had significantly lower SSR than the susceptible cultivar in three site-years (P < 0.01). The resistant cultivar also had significantly greater yield than the susceptible cultivar in two site-years (P < 0.05). Using a roller-crimped rye cover crop resulted in mixed results on SSR and yield. No effect on SSR or yield by OMRI-listed foliar fungicides was observed (P > 0.05). Overall, the results emphasize the importance of planting a resistant soybean cultivar to manage SSR in organic farming systems in the Midwestern United States. Copyright (c) 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

In silage corn (Zea mays L.), Fusarium graminearum causes diseases and produces the mycotoxin deoxynivalenol (DON). The work presented here investigated DON accumulation and its fate during the ensiling of ground, whole-plant material obtained from dual-purpose (DP) and brown midrib (BMR) corn hybrids. Multiyear field trials arranged in a randomized complete block design were conducted in Wisconsin to evaluate BMR and DP corn hybrids in response to fungicide treatment. At harvest, the samples were chopped and vacuum sealed for a mini-silo time series assessment with silos opened following anaerobic fermentation for 0, 30, 60, 90, and 120 days. Repeated measures analysis of ensiled corn showed that hybrid (P < 0.01) and ensiling duration (P < 0.01) significantly impacted DON concentration through ensiling, whereas fungicide treatment had no significant effect (P > 0.05). Across hybrids and treatments, DON concentrations detected at harvest were the lowest with DON-3-glucoside at harvest significantly (P < 0.01) and highly correlated (r = 0.74) with DON concentration 30-days after ensiling. These findings suggest that mycotoxin testing in corn should include not only DON but also conjugates of DON that can be metabolized back to DON and increase the final DON concentration during ensiling.

Calcium channels at synaptic boutons are critical for synaptic function, but their number and distribution are poorly understood. This gap in knowledge is primarily due to the resolution limits of fluorescent microscopy. In the last decade, the diffraction limit of light was surpassed, and fluorescent molecules can now be localized with nanometer precision. Concurrently, new gene editing strategies allowed direct tagging of the endogenous calcium channel genes-expressed in the correct cells and at physiological levels. Finally, the repurposing of self-labeling enzymes to attach fluorescent dyes to proteins improved photon yields enabling efficient localization of single molecules. Here, we describe tagging strategies, localization microscopy, and data analysis for calcium channel localization. In this case, we are imaging calcium channels fused with SNAP or HALO tags in live anesthetized C. elegans nematodes, but the analysis is relevant for any super-resolution preparations. We describe how to process images into localizations and protein clusters into confined nanodomains. Finally, we discuss strategies for estimating the number of calcium channels present at synaptic boutons.

In Wisconsin, the use of brown midrib (BMR) corn (Zea mays) hybrids for ensiling and subsequent feeding to dairy cows is quite common. The overall milk production from cows fed silage from BMR hybrids is typically higher than those fed silage made from dual-purpose hybrids. Gibberella diseases (ear and stalk rot) caused by Gibberella zeae (anamorph; Fusarium graminearum) and the accompanying accumulation of the mycotoxin deoxynivalenol (DON) can be significant issues during the field production of BMR hybrids. The work presented here aimed to understand the role of hybrid class on the distribution of F. graminearum DNA and DON in the ear and stalk parts of corn for silage. An ear and stalk partitioned sample experiment was conducted on silage corn from field trials in Arlington, Wisconsin, in 2020 and 2021. The trials were arranged in a randomized complete block design in both years, including one BMR hybrid, one dual-purpose hybrid, and seven fungicide application regimes. Paired ear and stalk samples were physically separated, dried, and ground at harvest before determining the concentration of F. graminearum DNA and DON in each sample. Across both years, the main effects of hybrid, treatment, and plant part were not significant (P > 0.1) on DON concentration. However, the hybrid-by-plant part interaction effect was significant (P < 0.01). Ears of the BMR hybrid accumulated the most DON, whereas the dual-purpose hybrid ears had the lowest DON concentration. The concentrations of DON and F. graminearum DNA were significantly (P < 0.01) and highly correlated in the ear (r = 0.73) but not in the stalk (r = 0.09, P = 0.33). These findings suggest that DON accumulation in the corn ear is a major contributor in the difference observed in the total DON between the hybrid classes. Therefore, growers and researchers are encouraged to focus production and breeding on hybrids in both classes that accumulate less DON in ears, resulting in lower total DON in corn chopped for silage.

Sclerotinia stem rot (SSR) of soybean caused by Sclerotinia sclerotiorum is a devastating disease of soybean, especially in the Upper Midwest region of the United States. To mitigate yield losses due to this disease, many control methods are available for producers, including cultural control practices, chemical control, and cultivars with quantitative resistance. However, due to there being few commercial cultivars with high levels of resistance, producers are often limited in their seed selection. The aim of this study was to develop novel conventional soybean cultivars with high levels of resistance to SSR, favorable agronomic traits, and resistance to additional economically important diseases. Initial crosses were conducted in 2016 with two different sources of SSR resistance. Across multiple generations of screening for resistance to SSR, three highly resistant soybean lines were identified as the elite lines. These elite lines were demonstrated to be highly resistant across multiple years in both greenhouse and field trials, including high levels of resistance to multiple diverse S. sclerotiorum isolates. The three selected elite lines also resulted in moderately high yields and favorable agronomic traits, such as low lodging and moderate branching, indicating their viability to be released for production. In addition to SSR resistance, these three elite lines demonstrated resistance to other economically important soybean diseases, such as frogeye leaf spot, anthracnose, Cercospora leaf blight, and brown stem rot. Overall, this work has led to three SSR-resistant soybean lines that could be useful for future breeding efforts or commercial soybean production. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Soybean production in the Upper Midwest region of the United States is consistently limited by the disease Sclerotinia stem rot (SSR). To control SSR, multiple management practices have been studied and implemented to reduce SSR development and preserve yield. This study examined the effects of integrating soybean seeding rates and pesticide programs under nitrogen fertilizer applications in the form of urea (46-0-0) that may occur due to management of other crops, such as corn. From 10 site-years between 2020 and 2021, low seeding rates decreased SSR development while also decreasing yields and partial profits. The effect of pesticide applications on SSR development was influenced by both seeding rates and nitrogen applications. Consistently, applications of the fungicide Endura reduced SSR to the lowest levels while also maintaining the highest yields and partial profits. Soybeans grown with nitrogen applications experienced increased SSR development and decreased yields and partial profits. Overall, this work suggests that using low seeding rates and fungicides improves the management of SSR, and using nitrogen fertilizer applications can result in greater SSR development and decreased economic returns, especially in fields with a history of SSR.

By engineering the point-spread function (PSF) of single molecules, different fluorophore species can be imaged simultaneously and distinguished by their unique PSF patterns. Here, we insert a silicon-dioxide phase plate at the Fourier plane of the detection path of a wide-field fluorescence microscope to produce distinguishable PSFs (X-PSFs) at different wavelengths. We demonstrate that the resulting PSFs can be localized spatially and spectrally using a maximum-likelihood estimation algorithm and can be utilized for hyper-spectral super-resolution microscopy of biological samples. We produced superresolution images of fixed U2OS cells using X-PSFs for dSTORM imaging with simultaneous illumination of up to three fluorophore species. The species were distinguished only by the PSF pattern. We achieved ∼21-nm lateral localization precision (FWHM) and ∼17-nm axial precision (FWHM) with an average of 1,800 - 3,500 photons per PSF and a background as high as 130 - 400 photons per pixel. The modified PSF distinguished fluorescent probes with ∼80 nm separation between spectral peaks.

Decisions about hybrid choice and fungicide application when growing corn ( Zea mays L.) for silage are important considerations to maximize sustainable production. The objective of this research was to evaluate how brown midrib hybrids compare with dual-purpose hybrids and how fungicides interact with these two classes of corn hybrids. To explore this, field research trials were conducted in Arlington, Wisconsin, in 2020 and 2021. In both years, the trials were arranged in a randomized complete block design and included one brown midrib hybrid, one dual-purpose hybrid, and seven fungicide application regimes. In-field disease ratings were made for tar spot (caused by Phyllachora maydis), ear rot, and stalk rot (caused by Gibberella zeae). Harvested silage was analyzed for yield, quality, and deoxynivalenol (DON) concentration. The selection of hybrid significantly ( P < 0.01) influenced the silage quality parameters, such as starch and total tract neutral detergent fiber digestibility, a measure of fiber digested throughout the tract of a cow. Fungicide use influenced dry matter yield ( P < 0.05), tar spot severity ( P < 0.01), and DON concentration ( P = 0.05). Our findings suggest that using appropriate fungicides improves yield and reduces disease severity and DON contamination. Better quality silage could be obtained from brown midrib hybrids at the expense of yield. Therefore, Wisconsin farmers are encouraged to primarily utilize a dual-purpose class of corn hybrids to ensure optimal milk production and secondarily apply fungicides to reduce DON levels in corn chopped for silage.

Field experiments were conducted in Illinois, Indiana, Iowa, Michigan, and Wisconsin, United States, and Ontario, Canada, in 2019 and 2020 to evaluate the integrated effects of host resistance, seed treatment, and seeding rates on root rot (RR) and foliar symptoms of sudden death syndrome (foliar disease index [FDX]) and soybean yield. Seed treatments included a nontreated control and fluopyram in 2019. In 2020, commercial base treatment, base + fluopyram, and base + pydiflumetofen were tested. The base treatment included metalaxyl + pyraclostrobin + fluxapyroxad + clothianidin. The 2019 nontreated control and the 2020 base treatment were considered controls in the analysis because previous studies showed that base treatments do not provide control for sudden death syndrome. The seed treatments were tested on susceptible and moderately resistant (MR) cultivars, which were planted at three seeding rates: 272,277, 346,535, and 420,792 seeds/ha. To mitigate concern that disease pressure may impact treatment, three high disease pressure (>20% FDX) site-years out of the 15 total site-years were grouped and analyzed separately. Seed treatment with fluopyram or pydiflumetofen both reduced FDX and protected yield. Fluopyram reduced RR by about 10%, but RR was not different between pydiflumetofen and the base treatment in 2020. Both seed treatments reduced FDX, but reduction was greater for fluopyram (43.2%) than for pydiflumetofen (24.3%) based on 2020 results. Seeding rate had no effect on foliar symptoms, but the highest seeding rate showed increased RR in 2019 and greater yield both years. Performance of MR cultivars was inconsistent across both years. In 2019, MR cultivars reduced RR by 8.9%; however, in 2020, the MR cultivar had more RR than the susceptible cultivar. Additionally, FDX was only reduced in the MR cultivar in 2020. Although host resistance and seeding rate did not individually impact disease development and yield in every site-year, we showed that integrating seed treatment, host resistance, and adequate seeding rates helped maximize yield in fields with sudden death syndrome.

Phyllachora maydis is a fungal pathogen causing tar spot of corn (Zea mays L.), a new and emerging, yield-limiting disease in the United States. Since being first reported in Illinois and Indiana in 2015, P. maydis can now be found across much of the corn growing regions of the United States. Knowledge of the epidemiology of P. maydis is limited but could be useful in developing tar spot prediction tools. The research presented here aims to elucidate the environmental conditions necessary for the development of tar spot in the field and the creation of predictive models to anticipate future tar spot epidemics. Extended periods (30-day windowpanes) of moderate mean ambient temperature (18–23 °C) were most significant for explaining the development of tar spot. Shorter periods (14- to 21-day windowpanes) of moisture (relative humidity, dew point, number of hours with predicted leaf wetness) were negatively correlated with tar spot development. These weather variables were used to develop multiple logistic regression models, an ensembled model, and two machine learning models for the prediction of tar spot development. This work has improved the understanding of P. maydis epidemiology and provided the foundation for the development of a predictive tool for anticipating future tar spot epidemics.