Scholarly Works, School of Plant and Environmental Sciences

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Leveraging deep learning for dollar spot detection and quantification in turfgrass
Kitchin, Elisabeth C. A.; Sneed, Henry J.; McCall, David S. (Wiley, 2025-01-01)
This study evaluates the effectiveness of fine-tuning a semantic segmentation model to identify and quantify dollar spot in turfgrasses, the most extensively managed and researched disease of turfgrasses worldwide. Using the DeepLabV3+ model, recognized for its capability to segment complex shapes and integrate multi-scale contextual information, the research leveraged a diverse dataset comprising various turfgrass species, disease stages, and lighting conditions to ensure robust model training. The trained model is able to identify and segment disease instances accurately and precisely, and the results indicate the potential for model-based assessment to outperform traditional visual assessment methods in speed, accuracy, and consistency. The development of deep learning models on extensive datasets like ImageNet requires significant computational resources. However, by fine-tuning a pretrained semantic segmentation model, we adapted it for disease segmentation using only a standard personal computer's graphics processing unit. This approach not only conserves resources but also highlights the practicality of deploying advanced deep learning applications in turfgrass pathology with limited computational capacity. The proposed model provides a new tool for turfgrass researchers and professionals to rapidly and accurately quantify this important disease under real-world growing conditions. Additionally, the findings suggest the potential to apply deep learning algorithms to other turfgrass diseases to support data-driven decisions. This could enhance disease management practices and improve decision-making processes for fungicidal treatments, thereby improving the economic and environmental sustainability of turfgrass management. Dollar spot is one of the most commonly studied turfgrass diseases, with researchers manually counting infection centers for quantification. A deep learning model was used to detect and quantify dollar spot from field research images. The dollar spot detection model accurately estimated dollar spot with limited false positives or false negatives. Described methods provide a tool for turfgrass scientists and professionals to rapidly quantify dollar spot from field images.
The impact of imidacloprid on the subterranean survivorship of Laricobius (Coleoptera: Derodontidae), a biological control agent of Adelges tsugae (Hemiptera: Adelgidae)
Hillen, Ashleigh P.; Foley, Jeremiah R.; Gross, Aaron D.; Mayfield III, Albert E.; Williams, Jacob; Xia, Kang; Salom, Scott M. (Wiley, 2025-05-01)
The invasive hemlock woolly adelgid (HWA), Adelges tsugae (Annand) (Hemiptera: Adelgidae), has spread throughout most of the range of eastern hemlock, Tsuga canandensis (L.), and the entire range of Carolina hemlock, Tsuga caroliniana (Engelman), in the United States. Integrated pest management (IPM) of HWA combines chemical applications with the release of biological control agents on untreated trees within the same stand. Laricobius spp., Rosenhauer (Coleoptera: Derodontidae), have been used as biological control agents of HWA since 2003 and have subterranean and arboreal life phases that are synchronous with HWA's lifecycle. When utilizing IPM tactics, there is potential for Laricobius spp. to settle below an insecticide-treated tree for its subterranean phase. Field investigations assessed the impact of historical (five years post treatment in 2017) and recent imidacloprid soil treatments (via soil injection, soil drench, and tablet in November 2020) on the subterranean survivorship of Laricobius spp. by quantifying concentrations of imidacloprid and its metabolites to determine its potential impact on percent adult emergence from the soil. We observed a significant treatment effect on mean soil concentration among application methods at the recent treatment site, but not the historical treatment site. Additionally, at the more recently treated site, significantly lower mean percent emergence was observed from soil drench and tablet imidacloprid applications after one year (2021), but by the following year (2022), that effect was no longer present. This study supports recent recommendations to delay releases of Laricobius spp. for one-year post-treatment with imidacloprid. Furthermore, these data suggest when applying imidacloprid to a stand established with Laricobius spp., soil injection techniques pose the least risk to their subterranean survivorship.
Spatial–Temporal Patterns of Methane Emissions from Livestock in Xinjiang During 2000–2020
Xu, Qixiao; Li, Yumeng; You, Yongfa; Zhang, Lei; Zhang, Haoyu; Zhang, Zeyu; Yao, Yuanzhi; Huang, Ye (MDPI, 2025-10-11)
Livestock represent a significant source of methane (CH₄) emissions, particularly in pastoral regions. However, in Xinjiang—a pivotal pastoral region of China—the spatiotemporal patterns of livestock CH₄ emissions remain poorly characterized, constraining regional mitigation actions. Here, a detailed CH₄ emissions inventory for livestock in Xinjiang spanning the period 2000–2020 is compiled. Eight livestock categories were covered, gridded livestock maps were developed, and the dynamic emission factors were built by using the IPCC 2019 Tier 2 approaches. Results indicate that the CH₄ emissions increased from ~0.7 Tg in 2000 to ~0.9 Tg in 2020, a 28.5% increase over the past twenty years. Beef cattle contributed the most to the emission increase (59.6% of total increase), followed by dairy cattle (35.7%), sheep (13.9%), and pigs (4.3%). High-emission hotspots were consistently located in the Ili River Valley, Bortala, and the northwestern margins of the Tarim Basin. Temporal trend analysis revealed increasing emission intensities in these regions, reflecting the influence of policy shifts, rangeland dynamics, and evolving livestock production systems. The high-resolution map of CH₄ emissions from livestock and their temporal trends provides key insights into CH₄ mitigation, with enteric fermentation showing greater potential for emission reduction. This study offers the first long-term, high-resolution CH₄ emission inventory for Xinjiang, providing essential spatial insights to inform targeted mitigation strategies and enhance sustainable livestock management in arid and semi-arid ecosystems.
Impact of species selection on plant community, sod tensile strength, and translocation rooting of a pollinator-garden sod
Askew, Whitnee B.; Godara, Navdeep; Brewer, John R.; Goncalves, Clebson G.; Goatley, Michael; Askew, Shawn D. (Wiley, 2024-11-01)
Interest in pollinator gardens is increasing to address pollinator decline. The establishment of perennial native plants often takes a few years and establishment projects are often lost to competition from unwanted weedy vegetation. Mature sod of pollinator-serving, native plants that is free of weeds would be highly desirable to conventional turfgrass sod consumers, thus offering a new revenue stream for traditional sod producers. The objective of this study is to evaluate the influence of four foundational species treatments on 3-year floral biodiversity of pollinator-serving plants, sod tensile strength, and transplant rooting strength. Results suggest that polycultures of pollinator-serving forbs can produce a marketable sod with sufficient tensile strength for lifting and translocating and sufficient ability to establish once relocated. Sod tensile strength, however, is insufficient for lifting when the plant community is not grown over plastic or does not contain a high-shoot density or rhizomatous foundation species such as hard fescue (Festuca longifolia Thuill.) or common yarrow (Achillea millefolium L.). Unfortunately, adding hard fescue or common yarrow markedly reduces the Shannon diversity index and species richness. The force needed to lift transplanted sod after 3 months was 5553 to 6969 N m-2 regardless of foundation species treatment and was numerically higher than the force reported by previous researchers to lift sod of various turfgrass species. Collectively, the data suggest that the best balance between preserving floral biodiversity and maximizing sod handling integrity would be approached by establishing pollinator-serving forbs alone or with a blend of native grasses over plastic. Mature, weed-free sod of native pollinator-serving plants offers a potential new revenue source for sod producers. Polycultures of pollinator-serving forbs yielded marketable sod with good tensile strength and transplant success. Optimal floral diversity and sod handling is achieved by planting forbs alone or with native grasses over plastic.
Blend ratios and mixtures of brown patch susceptible and resistant tall fescue cultivars
Powlen, Jada S.; McCall, David S.; Hensler, Kevin L.; Kerns, James P.; Fidanza, Michael A.; Bigelow, Cale A. (Wiley, 2024-11-01)
Brown patch (Rhizoctonia spp.) is a major disease of turf-type tall fescue (TF) [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.]. Many cool-season turfgrass lawns consist of species mixtures or cultivar blends, but the exact proportion of resistant cultivars in blends and mixtures to effectively reduce disease has not been well documented. A field study was conducted in West Lafayette, IN, and Blacksburg, VA, during 2022 and 2023 to determine the brown patch severity of various blend ratios (0%, 25%, 50%, 75%, and 100% by weight) using a brown patch susceptible and resistant TF cultivar. Additionally, mixtures (90% and 10% by weight, respectively) of TF and Kentucky bluegrass (Poa pratensis L.) with a susceptible and resistant TF cultivar were evaluated. Seasonal appearance/turf quality and brown patch severity were visually determined, and area under the disease progress curve (AUDPC) was calculated. Turf quality and brown patch severity were similar at both locations. Additionally, blends and mixtures containing >= 75% of the resistant cultivar maintained higher average visual quality across both locations compared to the susceptible cultivar alone. Between the two mixtures, the inclusion of a resistant TF cultivar maintained higher canopy density and increased the proportion of TF at both locations. Blends and mixtures containing >= 75% of a resistant cultivar reduced brown patch AUDPC by 71% and 83% in 2022 and 2023, respectively, when compared to the 100% susceptible cultivar. This field study reinforces the importance of selecting resistant TF cultivars to reduce seasonal brown patch symptoms in cool-season turfgrass lawns. Increasing the proportion of a resistant tall fescue cultivar in a blend significantly reduced brown patch severity. Turfgrass quality increased as the proportion of a resistant tall fescue cultivar increased in a blend. A brown patch-resistant cultivar in tall fescue: Kentucky bluegrass mix increased density and fescue composition. The proportion of Kentucky bluegrass significantly increased over time in tall fescue: Kentucky bluegrass mixtures.
A method to spatially assess multipass spray deposition patterns via UV fluorescence and weed population shifts
Koo, Daewon; Godara, Navdeep; Cubas, Juan R. Romero; Askew, Shawn D. (Wiley, 2025-01-01)
Spray deposition patterns from agricultural sprayers are traditionally sampled discretely along a field transect accounting for 0.5% or less of the treated area. Such methods may not fully capture the dimensional variability inherent in large-scale, multiple-pass spray applications, especially evident from an agricultural spray drone (ASD). This study investigated the utilization of UV-fluorescent dye and nighttime aerial imaging techniques to assess large-scale, multipass spray deposition patterns. Accuracy of digital hue from UV-fluorescent photography to predict deposition of proxy dye was confirmed via fluorometry assessed intensity levels of extracted UV-fluorescent dye from 384 Petri dishes placed prior to treatment. Results showed that ASD applications, regardless of nozzle type, exhibited greater spatial variability within the target area compared to ride-on sprayer applications, primarily due to overapplication. Additionally, the ASD generated spray drift to adjacent nontarget areas that was at least three times more than that of ride-on and spray-gun sprayers. Multipass deposition was further assessed via in situ smooth crabgrass infestation following treatment with quinclorac or topramezone by multipass ASD or hand-held, four-nozzle spray boom. Weed infestation annotated from overlaid grids with 9.3-dm2 ground resolution inconsistently detected spatial heterogeneity between transects assessed along the center and edge of each sprayer pass. The ASD controlled smooth crabgrass 11% more than the hand-held sprayer, albeit with an 18% increase in spray drift to nontarget areas, similar to the UV-fluorescence study. Digitally assessed average hue of fluorescence photography appears to be a viable method to assess multidimensional and continuous spatial relationships of spray deposition. Traditional spray deposition assessments lack spatial dimensionality. Nighttime UV-fluorescence photography of proxy dye accurately assesses spray deposition patterns. Spatial heterogeneity and drift increase with agricultural spray drones compared to ride-on sprayers. Weed infestation annotated via grid-overlaid aerial images resolves drift more than spatial heterogeneity. Despite erratic deposition, spray drones conserve or enhance weed control compared to a handheld boom sprayer. Spraying herbicides evenly is crucial for effective weed control. While the use of agricultural spray drones is increasing, there is limited understanding of their spray uniformity and drift potential. Inconsistent spray patterns can lead to overapplication or under-application, reducing weed control efficacy, or causing unintended crop damage. This study examined how agricultural spray drones, ride-on sprayers, and handheld spray guns distribute herbicides, using UV-fluorescent dye and nighttime imagery or aerial photos to detect weed population shifts. Results showed that ride-on sprayers applied chemicals more evenly, while drones and spray guns had more overapplication, especially with drones spraying too much directly below. Drones also caused more drift, but they achieved better weed control potentially due to fine spray particles covering more weeds. Although drones are less uniform, they can be effective for weed control but pose a higher risk of environmental impact through drift.
The bioherbicide Verticillium nonalfalfae effectively removes tree-of-heaven (Ailanthus altissima) but leaves many other non-native plants
Shively, Timothy J.; Barney, Jacob N.; Reid, J. Leighton; Salom, Scott M. (Cambridge University Press, 2024-12-01)
Tree-of-heaven [Ailanthus altissima (Mill.) Swingle] readily exploits disturbances, grows quickly into dense monocultures, and suppresses native plant species. The vascular wilt pathogen, Verticillium nonalfalfae, native to the eastern United States, has been proposed as a biocontrol agent for the invasive A. altissima. Studies consistently demonstrate the safety and efficacy of the bioherbicide, but they also note that the selective nature of the fungus does not preclude other invasive plants that commonly co-occur with A. altissima from occupying the site. We quantified the standing plant community and seedbank at several sites across Virginia 5 yr after inoculation with V. nonalfalfae to understand which species are present or being naturally recruited. Ailanthus altissima remained dominant in untreated areas but was nearly eradicated from the treatment plots. Other non-native species made up a large portion of the plant community and seedbank across all study areas, with no differences in their respective cover and count between treatments. While variability in plant community composition is high and site-specific context is important for establishing effective management strategies, planting native species and mitigating other invasives will be crucial to ensuring native species successfully establish in bioherbicide-treated areas.
Agricultural spray drone deposition, Part 2: operational height and nozzle influence pattern uniformity, drift, and weed control
Koo, Daewon; Goncalves, Clebson G.; Askew, Shawn D. (Cambridge University Press, 2024-11-01)
Agricultural spray drone (ASD) use in managed turfgrass has been given limited attention in the scientific literature. Further, deposition patterns of ASD spray have been obscured in previous research by ambient wind, crop canopy interference, and limited sampling resolution. Using a continuous sampling method involving blue colorant and water sprayed over white Kraft paper that was assessed via digital image analysis of stain objects and referenced spectrophotometric analysis of extractant, deposition metrics were estimated across a 29.3-m transect perpendicular to an ASD or ground-sprayer spray swath. The ASD applies very fine droplets that are highly concentrated with herbicide, similar to ultra-low volume treatments, that improved smooth crabgrass [ Digitaria ischaemum (Schreb.) Schreb. ex Muhl.] control compared with a ground sprayer when the ASD was operated 2 m above the turf. Unfortunately, these very fine droplets also drift, leading to four times greater droplet density at distance of almost 12 m away from the targeted spray swath following an operational height of 10 m compared with 2 m. As ASD operational height increases, drift and effective swath width at 30% coefficient of variation uniformity increases, while effective application rate, total deposition, and D. ischaemum control by quinclorac herbicide decreased. Total deposition decreased 6% for each meter increase in ASD operational height, likely due to evaporation. The potential losses due to evaporation are a serious consideration for ASD use that has received little attention in the scientific literature. Our data suggest that ASD operational height should be as low as possible, but modification of spray systems may be needed to improve homogeneity of spray pattern.
Agricultural spray drone deposition, Part 1: methods for high-throughput spray pattern analysis
Koo, Daewon; Henderson, Caleb A.; Askew, Shawn D. (Cambridge University Press, 2024-11-01)
Effective pesticide application is dependent on precise and sufficient delivery of active ingredients to targeted pests. Water-sensitive papers (WSPs) have been used to estimate the stain coverage, droplet density, droplet size, total spray volume, and other spray-quality metrics by analyzing deposit stains using image analysis software. However, because WSPs are expensive, they are typically distributed along unidimensional transects at intervals of 0.5 m or more, which comprises 0.5% or less of the total treated area. This might limit the ability to accurately represent the deposition of agricultural sprayers with irregular patterns, such as agricultural drone sprayers in the early developmental stage. This study introduces a novel approach utilizing white Kraft paper and a blue colorant proxy for assessing spray deposition. A custom Python-based image analysis tool, SprayDAT (Spray Droplet Analysis Tool), was developed and compared with traditional image analysis software, DepositScan. Both models showed increased accuracy in detecting larger objects, with SprayDAT generally performing better for smaller droplets. DepositScan underestimated the total deposited spray volume by up to 2.7 times less compared with the colorant extraction assessed via spectrophotometry and the predicted output based on flow rate, coverage, and speed. Accuracy of software-estimated spray volume declined with increasing total stain coverage, likely due to overlapping stain objects. Droplet density exhibited a Gaussian trend, with peak density at approximately 22% stain cover, offering evidence for overlapped stains for both DepositScan and SprayDAT as stain cover increased. Both models showed exponential growth in volumetric median diameter (VMD) with increasing stain cover. SprayDAT is freely accessible through an online repository. It features a user-friendly interface for batch processing large sets of scanned images and offers versatility for customization to meet individual needs, such as adjusting spread factor, updating the standard curve for spray volume estimation, or modifying the stain detection threshold.
Cereal rye cover crop termination management for Palmer amaranth (Amaranthus palmeri) suppression in soybean
Sias, Cynthia; Bamber, Kevin W.; Flessner, Michael L. (Cambridge University Press, 2024-10-30)
Palmer amaranth is a troublesome weed species displaying the ability to adapt and evolve resistance to multiple herbicide modes of action, and additional weed suppression tactics are needed. Growing interest in the use of cover crops (CCs) has led to questions regarding the most appropriate forms of CC management prior to cash crop planting in order to maximize weed suppression benefits. Experiments were conducted between 2021 to 2023 to test 1) cover crop termination timing (i.e., green or brown); 2) CC biomass amount; and 3) CC termination method (i.e., rolled or left standing) on Palmer amaranth suppression. Treatments included "planting brown" (cereal rye terminated 2 wk before soybean planting), "planting green" (cereal rye terminated at soybean planting), and a no-CC (winter fallow) check. Palmer amaranth emergence was evaluated at 4 and 6 wk after soybean planting, and yield was calculated at harvest. Palmer amaranth emergence was reduced when a CC was planted compared with the no-CC check, and more suppression was observed as CC biomass increased. This decrease in emergence is potentially due to a decrease in light reaching the soil surface and physical suppression as CC biomass increased. Yield, however, was unaffected by any CC management practice, indicating that growers can tailor CC termination practices for weed suppression. This information will provide better recommendations for farmers interested in using CCs for weed suppression. Overall, the importance of CC biomass accumulation to achieve weed suppression is highlighted in our findings. Additionally, we add to the growing body of documentation that soybean yield may be variable from year to year as a result of CC presence.
Auxin herbicides, halosulfuron, sulfentrazone, and topramezone disparately affect morphology and ultraviolet features of weedy flowers and associated pollinator foraging
Godara, Navdeep; Askew, Shawn D. (Cambridge University Press, 2024-11-01)
Pollinators risk exposure to insecticide residue when visiting weedy flowers in urban landscapes. Previous research shows that pollinators are routinely exposed to a variety of pesticides, but herbicides have exhibited minimal toxicity and did not contribute to the modeled risk quotients. Herbicides from different modes of action may deter pollinators from visiting turfgrass weeds, but their temporal influence on floral quality and pollinator foraging is unaddressed. Research experiments were conducted at Blacksburg, VA, in 2023 to assess the effect of four herbicides on floral morphology and ultraviolet (UV) reflectance of three different UV floral classes of weeds and associated pollinator foraging visits. Among 1,080 assessments per weed species, honeybees ( Apis mellifera), bumble bees ( Bombus spp.), solitary bees ( Chelostoma florisomne), and flies ( Diptera spp.) accounted for 94%, 2%, 3%, and 1%, respectively, of the total pollinator visitations on white clover ( Trifolium repens L.) inflorescences; 71%, 2%, 0%, and 27%, respectively, on dandelion ( Taraxacum officinale F.H. Wigg.) flowers; and 0%, 0%, 78%, and 22%, respectively, on bulbous buttercup ( Ranunculus bulbosus L.) flowers. Pollinator visitation and floral quality were temporarily affected by herbicide application, with some herbicides eliminating food resources, while others transiently impacted floral quality and density. The combination of 2,4-D + dicamba + MCPP and topramezone eliminated pollinator foraging visits, but on differing temporal scales of 3 d for auxins and 14 d for topramezone. Halosulfuron and sulfentrazone transiently suppressed floral quality and density, with varying degrees of deterrence on pollinators depending on the weed species. All evaluated herbicides reduced radiometric UV reflectance of T. officinale petal apices, but only synthetic auxin and topramezone reduced digitally assessed floral UV- reflecting area. Petal UV reflectance appears to contribute but not solely influence pollinator foraging behavior. UV-absorbing and UV-reflecting flowers differed in UV-reflectance response to herbicides, but pollinators were similarly deterred. Results suggest that herbicides may offer a variety of management solutions to pollinator deterrence in areas slated for insecticide treatment, including long-term or transient deterrence with potential food-resource preservation.
Optimizing liquid-applied iron sulfate rate and application interval for dollar spot suppression on golf course fairways
Soldat, D. J.; Hockemeyer, K.; McCall, David S.; Straw, C. M.; Koch, P. L. (Wiley, 2025-01-01)
Iron sulfate applications reduce dollar spot severity on golf course turfgrass, but further optimizing the use of iron sulfate may increase efficacy and encourage more widespread adoption by golf course superintendents. Three iron sulfate rates (9, 18, 36 kg ha-1), two application intervals (7 and 14 days), three water volumes (306, 612, and 1223 L ha-1), and combinations with fertilizer and fungicide products were evaluated at field locations in Madison, WI, Bloomington, MN, and Blacksburg, VA, in 2018 and 2019. Iron sulfate rate decreased dollar spot at all locations in a dose-dependent manner, and 7-day applications were more efficacious than 14-day applications. Water volume had no impact on disease severity at any location and combining iron sulfate with fertilizer had minimal impact as well. These results demonstrate improved iron sulfate strategies for dollar spot management and can be implemented by golf course superintendents in areas where fungicide resistance and fungicide regulations limit the use of traditional fungicides.
Optimizing fungicide application timing for spring dead spot based on soil temperature and season
Hutchens, W. J.; Booth, J. C.; Goatley, J. Michael Jr.; Roberson, T. L.; McCall, David S. (Wiley, 2025-01-01)
Spring dead spot (SDS) (Ophiosphaerella spp.) is the most detrimental disease to warm-season turfgrasses in areas with cold-induced dormancy. Fungicide applications do not provide consistent SDS suppression. One reason for this inconsistency is the use of solely calendar-based fungicide applications instead of considering both calendar date and soil temperature. A field study was conducted at three separate hybrid bermudagrass (Cynodon dactylon (L.) Pers. x transvaalensis Burtt Davy) locations in Virginia to determine the optimal soil temperature and timing for SDS suppression with tebuconazole and isofetamid. Tebuconazole (1.5 kg a.i. ha-1) and isofetamid (4.1 kg a.i. ha-1) were applied at 11 different timings throughout the year based on soil temperatures at a 0- to 10-cm depth. Plots were assessed for SDS severity in the spring and early summer of 2021 and 2022. Two in vitro studies were also conducted with Ophiosphaerella herpotricha and Ophiosphaerella korrae isolates to (1) determine the optimal temperature for growth on potato dextrose agar (PDA) placed on a thermogradient table (13-33 degrees C) and (2) compare the daily growth rate of O. herpotricha and O. korrae isolates at 11, 19, and 27.5 degrees C on PDA. In the field study, isofetamid suppressed SDS more than tebuconazole. Fall applications when soil temperatures were 13 degrees C consistently provided the best SDS suppression. For the in vitro studies, both species grew optimally between 24 and 25 degrees C, yet O. korrae and O. herpotricha growth rates differed at 11 degrees C.
A machine learning framework to predict PPCP removal through various wastewater and water reuse treatment trains
Choi, Joung Min; Manthapuri, Vineeth; Keenum, Ishi; Brown, Connor L.; Xia, Kang; Chen, Chaoqi; Vikesland, Peter J.; Blair, Matthew F.; Bott, Charles; Pruden, Amy; Zhang, Liqing (Royal Society Chemistry, 2025-01-30)
The persistence of pharmaceuticals and personal care products (PPCPs) through wastewater treatment and resulting contamination of aquatic environments and drinking water is a pervasive concern, necessitating means of identifying effective treatment strategies for PPCP removal. In this study, we employed machine learning (ML) models to classify 149 PPCPs based on their chemical properties and predict their removal via wastewater and water reuse treatment trains. We evaluated two distinct clustering approaches: C1 (clustering based on the most efficient individual treatment process) and C2 (clustering based on the removal pattern of PPCPs across treatments). For this, we grouped PPCPs based on their relative abundances by comparing peak areas measured via non-target profiling using ultra-performance liquid chromatography-tandem mass spectrometry through two field-scale treatment trains. The resulting clusters were then classified using Abraham descriptors and log Kow as input to the three ML models: support vector machines (SVM), logistic regression, and random forest (RF). SVM achieved the highest accuracy, 79.1%, in predicting PPCP removal. Notably, a 58-75% overlap was observed between the ML clusters of PPCPs and the Abraham descriptor and log Kow clusters of PPCPs, indicating the potential of using Abraham descriptors and log Kow to predict the fate of PPCPs through various treatment trains. Given the myriad of PPCPs of concern, this approach can supplement information gathered from experimental testing to help optimize the design of wastewater and water reuse treatment trains for PPCP removal.
Poison Ivy (Toxicodendron radicans) Leaf Shape Variability: Why Plant Avoidance-By-Identification Recommendations Likely Do Not Substantially Reduce Poison Ivy Rash Incidence
Jelesko, John G.; Thompson, Kyla; Magerkorth, Noah; Verteramo, Elizabeth; Becker, Hannah; Flowers, Joy G.; Sachs, Jonathan; Datta, Jyotishka; Metzgar, Jordan (Wiley, 2023-09-28)
Avoidance of poison ivy plants is currently the primary approach to prevent the estimated 30–50 million annual poison ivy skin rash cases. The “leaves of three let it be” mnemonic device lacks specificity to differentiate poison ivy from other three-leaflet native plants. This report demonstrated that poison ivy leaves show marked total leaf shape variability that likely confounds accurate poison ivy plant identification, and significantly undermines a poison ivy avoidance strategy for mitigating poison ivy rash cases. Therefore, there is an ongoing need to develop prophylactic medical procedures to prevent poison ivy rash that do not depend on human poison ivy plant identification. Summary: Urushiol is the natural product produced by poison ivy (Toxicodendron radicans) that is responsible for millions of cases of delayed contact allergenic dermatitis in North America each year. Avoidance of poison ivy plant material is the clinically recommended strategy for preventing urushiol-induced dermatitis symptoms. However, poison ivy leaf shape is anecdotally notoriously variable, thereby confounding accurate poison ivy identification. This study focused on quantitative analyses of poison ivy and a common poison ivy look-alike (American hog peanut) leaf shape variability in North America to empirically validate the high degree of poison ivy leaf shape plasticity. Poison ivy and American hog peanut iNaturalist.org records were scored for seven attributes of compound leaf shape that were combined to produce a total leaf complexity score. Both the mean and the distribution of poison ivy total leaf complexity scores were significantly greater than that of American hog peanut. Non-metric multidimensional scaling analyses corroborated a high degree of poison ivy leaf shape variability relative to American hog peanut. A poison ivy accession producing frequent palmate penta-leaflet compound leaves was evaluated using linear regression modeling. Poison ivy total leaf complexity was exceedingly variable across a given latitude or longitude. With that said, there was a small but significant trend of poison ivy total leaf complexity increasing from east to west. Palmate penta-leaflet formation was significantly correlated with a stochastic leaflet deep-lobing developmental process in one unusual poison ivy accession. The empirically-validated poison ivy leaf shape hypervariability described in this report likely confounds accurate poison ivy identification, thereby likely resulting in many accidental urushiol-induced clinical allergenic dermatitis cases each year.
Do Pastures Diversified with Native Wildflowers Benefit Honeybees (Apis mellifera)?
Larcom, Raven; Kietzman, Parry; O’Rourke, Megan; Tracy, Benjamin (MDPI, 2025-09-11)
Tall fescue-dominated pasturelands are widespread in the eastern United States and typically lack substantial plant diversity. Establishing native wildflowers into tall fescue pastures has the potential to benefit bee populations and boost pollinator ecosystem services. In this study, tall fescue pastures at five on-farm sites in Virginia, USA, were planted with wildflowers native to North America and paired with sites with conventional tall fescue pastures. Honeybee apiaries were established at the ten locations, and variables related to hive strength were measured over two years. The main study objectives were to: (1) compare metrics of hive strength between diversified and conventional pastures, (2) determine whether honeybees used native-sown wildflowers as a source of pollen, and (3) explore whether native-sown wildflowers were visited more by honeybees and other pollinators compared with nonnative, unsown forbs. Diversified pastures had many more plant species and blooms compared with conventional pastures, but this had little effect on hive parameters. Pollen DNA metabarcoding revealed that honeybee diets were similar regardless of whether hives were associated with diversified or conventional pastures. Honeybees foraged mostly on plants in the surrounding landscape—especially white clover (Trifolium repens) and less so on native wildflowers. Native-sown wildflowers received more visits from native pollinators, however. We hypothesize that the native-sown wildflowers had little impact on hive strength metrics because honeybees had access to abundant, white clover blooms and other flowering species in these landscapes. Native wildflowers that bloom in late summer/early autumn after white clover blooms diminish may be of greater value to honeybees in pasture settings.
The Effects of Endophyte-Infected Tall Fescue on the Production and Reproductive Performance Parameters of Beef Cattle and Calves
Taylor, Amber A.; Fike, John H.; Mercadante, Vitor R. G.; Pent, Gabriel J. (MDPI, 2025-07-15)
Records from 2012 to 2019 for two herds were analyzed to determine how tall fescue (Schedonorus arundinaceus (Schreb.) Dumont) endophyte (Epichloë coenophialum) status affected the productivity of spring-calving cows and calves. Pastures either contained tall fescue with wildtype endophyte (high levels of ergot alkaloids) or novel- or endophyte-free tall fescue (largely ergot alkaloid free). The experimental design was a randomized complete block with year as the replication unit. Forage samples from the farm with toxic endophyte-infected tall fescue contained 1136 ± 413 ppb total ergot alkaloids, while forage from the non-toxic pastures on the second farm contained 118 ± 83 ppb total ergot alkaloids. Artificial insemination pregnancy rates and calving rates were greater (p < 0.05) for cows that grazed non-toxic tall fescue (51.2 ± 2.8% and 93.5 ± 1.4%, respectively) than for cows on toxic endophyte-infected tall fescue (43.3 ± 2.8% and 88.8 ± 1.4%, respectively). Birth weights and weaning weights were greater (p < 0.05) for calves from the non-toxic tall fescue system (37 ± 1 kg and 278 ± 8 kg, respectively) than for calves from the toxic endophyte-infected tall fescue system (33 ± 1 kg and 254 ± 8 kg, respectively). Raising cattle on tall fescue without the toxic endophyte improved cow and calf productivity.
Reducing Heat Without Impacting Quality: Optimizing Trypsin Inhibitor Inactivation Process in Low-TI Soybean
Xiao, Ruoshi; Rosso, Luciana; Walker, Troy; Reilly, Patrick; Zhang, Bo; Huang, Haibo (MDPI, 2025-08-29)
A soybean meal is a key protein source in human foods and animal feed, yet its digestibility is constrained by endogenous trypsin inhibitors (TIs). Thermal processing is the mainstream tool for TI inactivation, but high-intensity heat treatments increase energy consumption and can potentially denature proteins, diminishing nutritional quality. Reducing the thermal input while maintaining nutritional quality is, therefore, a critical challenge. One promising strategy is the use of soybean cultivars bred for low-TI expression, which may allow for milder processing. However, the performance of these low-TI cultivars under reduced heat conditions remains unstudied. This study treated soybean samples under four different temperatures (60, 80, 100, and 121 °C) for 10 min and investigated the impact of heat treatment on TI concentration, in vitro protein digestibility, and nutritional properties of meals from a conventional high-TI variety (Glenn) and a novel low-TI variety (VT Barrack). Results showed that heat treatment at 100 °C significantly improved protein digestibility and lower TI concentrations in both varieties. A negative correlation was observed between protein digestibility and TI concentration in both soybean varieties. At 100 °C, the low-TI variety achieved 81.4% protein digestibility with only 0.6 mg/g TIs, whereas the high-TI variety required 121 °C to achieve comparable protein digestibility and a TI reduction. These findings highlight that low-TI soybeans can lower the necessary thermal treatment to 100 °C to minimize TIs while simultaneously preserving protein quality and cutting energy demand, offering a practical, cost-effective approach to producing higher-quality soybean meals.
Evaluation of Peanut Physiological Responses to Heat and Drought Stress Across Growth Chamber and Field Environments
Vennam, Ranadheer Reddy; Beard, Keely M.; Haak, David C.; Balota, Maria (MDPI, 2025-08-28)
Heat-exacerbated drought stress is becoming increasingly common in crop production systems, including peanuts, yet limited information exists on how peanut cultivars respond to this combined stress. While controlled environments allow for the isolation of these stress effects, their relevance to field conditions remains unclear. In this study, five Virginia-type peanut cultivars were evaluated under four treatments in a growth chamber environment, i.e., control, heat, drought, and combined heat and drought stress; and under two treatments in the field environment, i.e., rainfed control, and combined heat and drought stress using rainout shelters. The physiological traits assessed included stomatal conductance and transpiration rate, as well as leaf temperature difference. In both environments, combined heat and drought resulted in a significant decline in physiological performance compared to control conditions. On average, stomatal conductance decreased by 65% in the growth chamber and 21% in the field under combined heat and drought stress, while transpiration was reduced by 49% and 24%, respectively. In the growth chamber, leaf temperature difference increased by 40% under combined stress, whereas it was not statistically different under field conditions. Correlations of the physiological responses between growth chamber and field were stronger under combined stress conditions than under control conditions. Principal component analysis revealed clear genotypic separation based on gas exchange and thermal traits, with NC 20 and Sullivan consistently associated with higher stomatal conductance and transpiration under stress across environments, indicating greater physiological resilience, while Emery clustered with traits linked to stress susceptibility. These findings underscore the significant impacts of combined stress in peanut production and highlight the importance of evaluating cultivar responses under both controlled and field environments to guide crop improvement strategies.
Towards Understanding the Promotion of Plant Growth Under an Experimental Red-Fluorescent Plastic Film
Stallknecht, Eric J.; Runkle, Erik S. (MDPI, 2025-08-19)
Semitransparent plastic films containing red-fluorescent pigments can increase the growth of some greenhouse crops despite a lower transmitted photosynthetic photon flux density (PPFD), but the underlying mechanism by which this occurs is not fully understood. We postulated it can be attributed to a lower blue-light environment that increases leaf expansion and thus photon capture. We examined the growth response and photosynthetic capacity of vegetable and ornamental greenhouse crops under a red-fluorescent plastic, plastics with varying transmission percentages of blue light (from 6% to 20%), and an uncovered greenhouse control with a 40% greater PPFD. When the transmitted PPFD was similar, decreasing the percentage of blue light increased the extension growth for some but not all species tested. Transmitted PPFD had a more pronounced effect on extension growth than the percentage of blue light. Lettuce shoot dry mass was greater under the red-fluorescent film than the other covered treatments and similar to the uncovered control with 40% more light. Regardless of the transmission spectrum, decreasing the transmitted PPFD reduced tomato fruit fresh mass and generally decreased the number of flowers ornamental on the species. Maximum photosynthetic rate (A_max), stomatal conductance (g_sw), and quantum yield of photosystem II (PhiPSII) consistently decreased as the percentage of blue light transmission decreased, but this did not correlate to biomass accumulation. An experimental red-fluorescent film had cultivar and species-specific effects on growth, highlighting both its potential for leafy greens and potential challenges for greenhouse crops with a greater quantum requirement.

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