ASHS 2024 Conference

Field-Based Remediation Strategies for Groundwater Nitrogen Contamination
Can Healthy Soil Make Healthy People? Investigating The Impact Of Soil Biota On Micronutrient Uptake In Vegetable Crops
Optimizing nitrogen fertilizer concentrations in vegetable transplant production
Growing Resilient Broccolini: Harnessing Clover Living Mulch for Weed Suppression and Yield Enhancement
Foliage Removal on Processing Sweet Corn Reduces Yield Most Strongly Near Tasseling
Optimizing Planting Density of Sweet Corn in Georgia
Boosting Sweet Corn Yields: The Power of Biochar and Fertilizers Unveiled

Agricultural pollutants are commonly detected in Wisconsin groundwater samples, particularly in areas with coarse-textured soils and high input agriculture. Practical and effective techniques are needed to reduce contaminants in agricultural leachate to protect human health and the nearby environment. Organic soil additives may be able to capture excess nitrogen fertilizer in the soil and prevent groundwater contamination with minimal grower expense. Five soil additives were tested in soil columns for nitrogen fertilizer capture ability. Two biochar treatments, two papermill waste treatments, and one humic acid treatment was tested against an untreated control. Leachate volume remained constant among treatments, but biochar and papermill waste treatments reduced nitrogen content in leachate (up to 8.5% and 35%, respectively). Humic acid was ineffective at reducing nitrogen content in leachate in an abiotic system, prompting a second soil column experiment currently underway that includes live potato plants. Intercropping systems may also be able to reduce agricultural pollutants in groundwater. Potatoes were intercropped with adjacent strips of fall-planted winter rye, spring-planted winter rye, and spring-planted yellow mustard to investigate the effects of companion crops on potato yield compared to a monoculture potato control plot. Intercropping did not impact potato yield or size distribution compared to monoculture potato. A second intercropping study was designed to explore potato yield when companion crops were planted directly in the furrow between each potato row. Treatments included a spring-planted winter rye and a spring-planted yellow mustard, seeded at three intervals post hilling, with nitrogen fertilizer banded over the potato row or conventionally broadcast. Neither intercropping nor fertilizer application method affected potato yield. Further research is underway to test intercropping systems in other high-nitrogen vegetable crops such as sweet corn.

The health of humans and ecosystems are closely interlinked, therefore fostering healthy soils may aid in addressing micronutrient deficiencies. Healthy soils are active with diverse microbial and mesofauna communities that carry out soil processes that are essential for crop growth and development. A greenhouse experiment was conducted to investigate the effect of soil mesofauna on micronutrient content in vegetable crops and determine if plant root structure or shifts in soil microbial community composition (relative pathogen abundance) impact these affects. Crop species (snap beans and beets), Collembola (Isotomiella minor) abundance (none, low, or high), and microbial community composition (native community and pathogen-dense community) treatments were imposed and replicated five times. The soil treatments were prepared by sterilizing soil and inoculating the soil with the two different microbial communities. The inoculated soil was placed in pots and one cup of compost was mixed into the top 5 cm. Snap beans and beets were planted at a depth of 2.5 cm and 0.25 cm, respectively. The Collembola treatments (none, 100 Collembola, 200 Collembola) were then added to the appropriate pots. Weekly checks were conducted to monitor plant health and growth. Once each crop reached maturity (approximately 60 days), a destructive harvest was conducted. Crop biomass and marketable yield fresh weights were recorded and I. minor abundance was verified at the harvest. Crop biomass samples were frozen for later analysis of minerals relevant to human health including essential nutrients (e.g., calcium, sodium, magnesium, potassium, iron, and zinc) and heavy metals (e.g., lead, cadmium, and arsenic). Minerals were extracted via microwave digestion in nitric acid and quantified via ICP-MS. We hypothesized that the concentration of micronutrients in the vegetables will increase as I. minor abundance increases, and that the I. minor will have a greater effect on the snap bean compared to the beets due to the greater root surface area. Additionally, we conjectured that a pathogen-dense microbial community will diminish the effects of I. minor on micronutrient uptake, since greater pathogen presence would likely decrease their direct interactions with crop roots. We found that the addition of I. minor enhanced crop growth regardless of soil microbial community composition. The beets were more sensitive to changes in soil microbial community composition compared to the snap beans. Our findings illustrate the importance of healthy soil biological communities for quality vegetable production.

Vegetable transplant producers supply approximately $250 million worth of transplants to vegetable growers throughout the United States. Proper nutrient application for transplant production is important for crop establishment and minimizing excessive fertilizer waste which can negatively affect surface and groundwater. However, nutrient application guidelines for vegetable transplants grown in soilless substrate are limited. Therefore, researchers undertook a study to determine optimal nitrogen (N) concentrations for the top five transplanted vegetable crops produced in California. Greenhouse trials were conducted on leaf lettuce, romaine lettuce, processing tomato, broccoli, and celery transplants. Three treatments were applied in each trial (One 200-cell plug tray per treatment, replicated five times each): (1) 400 ppm N; (2) 200 ppm N; (3) 50 ppm N. Fertigation was applied to trays placed on weighing-lysimeters and total daily transpiration was recorded. Once transplants were fully developed, they were harvested and analyzed for shoot fresh weight and shoot dry weight. Fresh plant tissue was sent to an agricultural laboratory for nutrient content testing. Total nutrient uptake (mg) was calculated by multiplying nutrient tissue content (%) by shoot dry weight (mg). N fertilizer concentration (mg*L-1) was calculated by dividing the total N uptake value (mg) by transpiration (L). Transplants in the 400 ppm treatment had significantly higher N tissue content, compared to the 200 and 50 ppm treatments, in all crop trials except for leaf lettuce. In the leaf lettuce trial, the 400 and 200 ppm treatments had similar N tissue content. Average shoot dry weight was similar between the 200 and 400 ppm N treatments in all five crops, indicating that both treatments provided sufficient N. Based off these results, we recommend applying 246 ppm N to leaf lettuce, 232 ppm N to romaine lettuce, 304 ppm N to processing tomato, 437 ppm N to broccoli, and 262 ppm N to celery transplants. These values are based off the calculated N fertilizer concentrations which produced the highest shoot dry weights.

Growing broccoli to a marketable standard can be difficult in a changing climate with more extreme heat events during the growing season. The use of more heat tolerant Brassica species in combination with living mulch could address both issues. A study in Brookings, SD investigated established clover living mulch and in-row soil management impacts on the performance of four of broccolini (Brassica oleracea) cultivars – ‘Melody,’ ‘BC1611,’ ‘Burgundy,’ and ‘Bonarda.’ Three established clover varieties (‘Domino’ white clover (Trifolium repens), ‘Aberlasting’ white x kura clover (T. repens x ambiguum), and ‘Dynamite’ red clover (Trifolium pratense)) and a bare-ground control were used in combination with four in-row soil management strategies (till, no-till, till fabric, and no-till fabric). These 16 combinations were evaluated for their impact on weed suppression, broccolini crop growth and yield. It was observed that annual weeds such as yellow foxtail (Setaria pumila) and Venice mallow (Hibiscus trionum) were present in bare ground plots and were reduced in all clover plots. Some perennial weeds such as dandelion (Taraxacum spp.) and perennial sow thistle (Sonchus arvensis) were able to compete with clover. Sufficient clover biomass was accumulated for weed suppression. Weed biomass was reduced by 80% in white and red clover plots, and 95% in the white x kura clover plots compared to the control. Broccolini yield was reduced within all three clover no-till treatments. Broccolini grown in other clover soil management combination had similar yields indicating greater resistance to yield decreases commonly observed in living mulch research. Other data collected in this study included clover nodule counts and broccolini crop health metrics – height, canopy width, and SPAD. Results from the first year of research demonstrate that perennial clover living mulch can be used in the Great Plains to suppress weeds between planting rows. However, the use of landscape fabric within the planting row is necessary to prevent a reduction in broccolini yield. Planting broccolini into a living mulch system shows potential for vegetable producers to reduce inputs and labor on their farms while maintaining crop yield.

Sweet corn is an important processing crop in the upper Midwestern United States. It can be insured for hail losses, but actuarial tables are based on field corn. The first step in developing accurate yield loss estimates is to determine yield loss due to stand loss. The second step is to determine yield loss due to defoliation. To understand the impacts of defoliation on sweet corn yield, we compared ear yield with estimated 25, 50, 75, or 100% of leaf area removed at five times throughout the growing season to control plots that were not defoliated. Defoliation was carried out with a Christmas tree shearing knife or machete. We repeated this in three consecutive years at two locations, without irrigation or supplemental fertilizer. Yield was measured as both green ear mass and cut kernel mass. Measured loss due to defoliation was generally less than actuarial estimates, except shortly before tasseling or at 25% defoliation. A regression equation predicting yield relative to control based on a) growing degree days before damage and b) percent defoliation were developed, combining all site-years. We measured little yield loss with 25 or 50% defoliation or 75% defoliation near V8, and we measured greatest yield loss near tasseling with 100% leaf removal. Kernel and ear mass were strongly correlated. These results illustrate resilience of sweet corn to foliage loss and potential need for adjustment of actuarial tables for hail loss.

Currently, most sweet corn in the state of Georgia is produced and shipped wholesale for fresh market consumption. The majority of producers in the state aim for a Fourth of July harvest, and shipper sweet corn is a significant source of income for Georgia vegetable growers. Plant population density is a critical factor for achieving optimal yield while balancing resource inputs, and the commercial standard for sweet corn in the state is 60,000 to 74,000 plants ‧ ha-1. While recent research in the midwestern U.S. suggests that planting densities for processing sweet corn can be pushed above previously recommended ranges to optimize profit, little work has been done in current years concerning fresh market shipper sweet corn in the southeastern region of the country, which differs drastically in soil type and seasonal weather patterns. Therefore, the objective of this study is to re-evaluate current state guidelines for plant population density to optimize marketable yields by manipulating inter- and intra-row plant spacing. To do this, sweet corn (cv. ‘Obsession’) was sown directly to the field in the spring season of 2023 at a rate of 43,000 to 107,000 plants ‧ ha-1, which was achieved with sowing patterns in either two or three rows per bed top (91 cm or 46 cm apart, resp.), and five within-row spacings ranging from 15 cm to 25 cm at 2.5 cm increments. The field was managed according to the University of Georgia's irrigation, fertilizer, insect, and disease management guidelines. At harvest, the number, size, and tip fill of ears were collected, with marketable ears categorized based on USDA Fancy grading standards for a minimum length of 15 cm and unfilled kernels at tips covering less than one-fourth cob length. A significant increase in marketable yield was associated with the number of rows but not within-row spacing, with an average increase of 24% in three-row treatments (p < 0.05). There was not a significant difference in unmarketable yield between row treatments. Preliminary results indicate that plant population density for shipper sweet corn in Georgia can be increased by adding a third row while maintaining fresh market quality.

This study explored the efficacy of biochar, derived from paper mill waste, in enhancing soil properties, plant growth and yield in sweet corn when used with organic (poultry litter) or inorganic fertilizers. Conducted in spring 2023, the field trial assessed biochar application rates (0, 10, 15, and 20 tons/acre) combined with fertilizers supplying 225 lbs N/acre in a randomized complete block design with four replications. Our results indicate that biochar's effectiveness is limited when used alone but significantly affects soil nutrients and crop outcomes in combination with fertilizers. Inorganic fertilizers, compared to organic, were more effective in improving yield metrics such as ear number, weight, and width. In addition, our findings suggest that the interaction of biochar and fertilizer type significantly influences soil nutrient levels. Biochar and inorganic fertilizer generally exhibited a strong negative correlation with nutrients like nitrogen (N), indicating a notable decrease in N soil content with lower biochar application rates. Suggesting that biochar can mitigate nutrient depletion when combined with inorganic fertilizers. Conversely, when biochar is applied alongside organic fertilizers, the outcomes vary across different nutrients. For magnesium (Mg) and calcium (Ca), positive correlations emerge at higher application rates, hinting at biochar's role in enhancing the bioavailability of these nutrients in organically fertilized soils. Regarding plant growth and development, the analysis revealed that the interaction between fertilizer type with biochar and biochar rate alone had no significant effect on most measured growth parameters. However, the fertilizer type used did significantly affect some growth parameters. Specifically, plants grown with organic fertilizer had significantly higher fresh weight of roots and total dry plant weight than those grown with inorganic fertilizer. It was found that the highest rate of biochar (20 tons/A) raised soil pH significantly at 90 days, reaching 6.65 pH in the inorganic treatment and 7.0 pH in the organic treatment. The pH was lowest in the treatments without biochar (0 tons/acre) at 90 days after application (5.1 pH inorganic and 6.0 pH organic treatments respectively). Furthermore, biochar application was linked to increased soil microbial activity, as evidenced by CO2 burst measurements. These significantly rose with higher biochar rates under both fertilizer regimes, albeit without a significant interaction effect between biochar and fertilizer type on CO2 burst. These findings suggest that integrating biochar with fertilization strategies can enhance soil health and sweet corn production, offering a sustainable approach to managing soil nutrients and improving crop yield.

The Kentucky Small Fruits Initiative: An Extension-Industry Partnership - Cindy Finneseth
Case Study: Assessing Workforce Training Needs And UMKC Student Interest To Develop Controlled Environment Agriculture Education In Kansas City - Juan Cabrera Garcia
Assisting Florida Sod Producers with Protecting Water Quality by Quantifying Nutrient Inputs and Exports - Bonnie Wells
Will Consumers Purchase a Landscape Scouting Program? - Andrew Jeffers
Native Plant Extension Programming for Commercial Horticulture Professionals - William Errickson

Growers in Kentucky are increasingly interested in adding small fruit crop enterprises to their farming operations. While consumer demand is high, available capital and limited production knowledge are known barriers for small- and mid-scale producers interested in growing and selling these crops. The Kentucky Horticulture Council (KHC) and the University of Kentucky (UK) partnered on a financial and technical assistance support program for Kentucky growers with an interest in producing these crops. Over the 4-year project, more than $936,000 was invested in on-farm projects, working with 275 existing and 76 pre-commercial growers in 89 different counties across the state. Blackberry, blueberry, and strawberry were the highest demand crops. Irrigation, trellising, and netting were the most requested non-plant material inputs. The expected farm impact over the next 10 years will exceed $7.4M, based on yield and sales price estimates. The funding model providing financial assistance to current and prospective growers along with extension’s role in delivering research-based information and providing technical assistance will be discussed. The presentation will also focus on strategies to recruit and screen program participants by assessing needs, setting realistic expectations, increasing production knowledge and skills, with the goal of fostering satisfaction and meeting the intended project objective of increasing small fruit crops profitability for commercial sales over the next decade and beyond.

Controlled environment agriculture (CEA) integrates technology to optimize crop performance. The project goal was to inform the development of CEA curriculum by understanding CEA workforce training needs and gauging student interest at the University of Missouri – Kansas City (UMKC). CEA industry surveys determined the knowledge/skills needed for employment and educational expectations. A second survey was sent to UMKC students to gauge their knowledge of/interest in a CEA educational program. The top five positions in demand by the CEA industry were: (1) manager, (2) worker, (3) research

Adherence to the Florida Department of Agriculture's (FDACS) Best Management Practices (BMP) program is crucial for sod producers to protect water quality. Challenges arise due to perceived low fertilization rates and accelerated production cycles, particularly in South Florida. Challenges are exacerbated by the nutrient export that occurs when harvested sod carries away soil-bound nutrients and residual fertilizer. The sod BMP manual is undergoing revision, with a proposed emphasis on achieving a nutrient balance of nitrogen (N) and phosphorus (P) inputs/exports in sod operations. However, current published data on nutrient export needs to be more comprehensive, necessitating research efforts to fill this knowledge gap. This project, funded by a 2022-2023 FDACS BMP grant, aims to educate and improve sod producer BMPs by assessing current practices and quantifying nutrient inputs/exports through sod slab analysis. A Qualtrics survey was designed to measure sod producers' current BMP practices. Visits to sod farms were employed to collect sod slab samples for nutrient inputs/exports data processing. Results, particularly regarding N and P export, revealed variability across turfgrass species, highlighting the need for further research to determine nutrient sinks and explore the influence of soil depth on nutrient export during harvest. The project's future focus involves providing targeted training based on results to Florida sod producers and exploring additional funding opportunities to address remaining key questions. Results of this project will improve nutrient management inputs/exports budgeting by sod producers and facilitate adoption of practices that improve nutrient management for sod production statewide.

The US landscape industry comprises 632,000 businesses with >1 million employees in 2022. The most common service landscape service providers (LSPs) perform is pest management. Over the past 25 years, consumers have increasingly requested that LSPs use more holistic approaches to pest management, including nonchemical and less toxic chemical control methods. Integrated pest management (IPM), specifically scouting, may be useful for LSPs to manage pests more sustainably and market new services, such as biological control releases. Little published literature details LSP scouting practices or consumer acceptance of scouting services. The goal of this study was to determine if IPM-aware consumers were more likely to purchase a scouting program offered by a LSP. A third-party panel service distributed an online survey across the United States. The final sample included 928 usable responses. Data were analyzed using a binary logistic regression model. Fifty-seven percent of respondents reported having some knowledge or that they were very knowledgeable of IPM. Increased consumer knowledge of IPM increased purchase likelihood. Respondents who self-reported “some knowledge” (5.6%) and “very knowledgeable” (8.6%) of IPM were more likely to buy scouting services. Respondents 65 years of age and older were 13.1% less likely to purchase a scouting service, regardless of IPM knowledge level. Consumers open to purchasing a scouting program, may also be more willing to allow a LSP to use a combination of chemical and nonchemical methods to manage pests. Further research is needed to determine consumer willingness to pay for scouting programs as well as non-chemical treatment options offered by LSP.

Native plants are becoming increasingly popular choices for low-input ornamental landscapes in residential and commercial applications. Many nurseries and landscape professionals are currently growing or offering at least some native plants in response to this increasing demand. However, supplies are still limited and there are specific best management practices associated with growing, marketing, and maintaining native plants that need further development. In response to this need from the green industry, replicable, applied programming focused on supporting growers who are currently producing or have an interest in producing native plants was developed. To first prioritize the needs of the industry, a state-wide native plant needs assessment survey was developed and disseminated to nursery and landscape professionals. The survey received 60 responses and indicated that native alternatives to invasive species, deer resistant native plants, and new cultivars of native plants were among the top priorities, in addition to IPM practices, stress tolerance, and propagation protocols. Based on this direction from stakeholders, extension programming was developed to meet these needs and support the green industry in their production and marketing of native plants. Educational programs focused on commercial native plant production and management were developed and delivered both in-person and virtually through webinars, while twilight meetings, including sessions at established native plant nurseries, facilitated grower-to-grower learning and interaction. Program evaluation surveys indicated strong metrics for knowledge gain, incorporating more native plants in their operations, reducing inputs, and achieving better pest control measures. Field trials comparing cultivars of deer-resistant native ornamental grasses offered growers and landscapers a chance to observe how these plants performed throughout three growing seasons, while offering a low-input alternative to non-native species in the landscape. Propagation trials were conducted to begin optimizing protocols for both vegetative cuttings and seed propagation of locally collected native ornamental plants, with success rates documented for each species using standard propagation protocols. A video was also created and shared with stakeholders showcasing a virtual tour of a commercial golf resort that has successfully incorporated native plants into their landscape, thus serving as an example for how to achieve an ornamental landscape aesthetic using native species. While native plant species may vary among ecoregions, this comprehensive approach is replicable and has been met with a high degree of satisfaction from commercial horticulture professionals.

Identifying the Ideal Combination of Strawberry Variety and Climate Control for Greenhouse Cultivation in Michigan -Amanda Jessica Da Silva
Economic impact of Winter Injuries on Golf Courses in North America - Chengyan Yue
Producing Sweet Potatoes to Manage Farm Income Risk in North Carolina - Godfrey Ejimakor

Strawberries are among the most popular fruits consumed in Michigan. However, Michigan's climate conditions hinder local production on a commercial scale. Outside of the summer period, production is only viable through controlled environment cultivation. Consequently, local demand relies on shipments from other U.S. producing regions, such as California and Florida, or imports mainly from Mexico. Given the delicate nature of this fruit, the long-distance supply chain can compromise the quality of the fruit, leading to substantial losses at retail and consumer levels. These factors drive the need to identify strategies to extend strawberries production season and empower a resilient regionalized supply chain. Our study aimed to optimize economic returns of greenhouse strawberry growers in Michigan using a bioeconomic modeling approach. Three strawberry varieties, namely Albion, Cabrillo, and Monterey, were grown in a greenhouse utilizing five different temperature treatments. The temperature treatments employed during the day and night cycles were set as 15/7° C, 10/18° C, 21/13° C, 24/16° C, and 27/19° C, respectively. Data was collected on productivity per plant and transplanted into a commercial grower scenario. The spatial-temporal bioeconomic model simulated the implementation of 15 hypothetical greenhouses, each covering an area of 1,000 m2, to accommodate one variety and one treatment at the time. Using a partial budget analysis, the research identified profitability capacity for greenhouse strawberry cultivation. From a costing perspective, the model considered the most important operating costs, including energy consumption by supplemental lighting and heating systems, labor requirements, materials (runners, fertigation, etc.), and growing space requirements. As for revenue, the model estimated potential revenues based on production capacity and market prices. By integrating these factors, the model provided estimates of the impacts of different combinations of strawberry varieties and treatment on fruit production. All three varieties had lower productive performance in the 15/7° C treatment, with Albion and Monterey only producing strawberries in weeks 8 and 9. The 24/16° C treatment showed the best productivity for all varieties, with Monterey achieving best economic results, followed by Cabrillo and lastly, Albion.

Golf courses in the northern regions of the United States and Canada experience occasional damage from winter stresses. This damage can sometimes be very severe, resulting in substantial financial impacts. Winter damage to turfgrass surfaces affects golf course finances in three primary ways: pre-winter maintenance costs, post-winter repair expenses, and revenue losses due to delayed openings. In 2022, a survey was conducted among golf course superintendents in the northern USA. and Canada. This survey collected data on the causes of winter injuries, the extent of damage across the golf course and various management practices employed. Preliminary results have shown that on average the annual costs incurred for preventing winter injuries were between $12,291 and $13,790 and the additional costs resulting from winter injuries ranged from $7,452 to $8,951 per golf course.

The resilience of farmers and farm families are often threatened by the risk associated with farm income. One of the sources of farm income risk is the volatility or variability in crop yields. Climate change or crisis could amplify this risk thereby making farmers, their families and communities less resilient. One of the ways that farmers could manage farm income risk is to diversify their operations by adding crop enterprises. Enterprise diversification works best as an income risk management strategy if the returns from the crop that is being added is negatively correlated with the returns from the other crops. Understanding how the income from some crops or enterprises correlate with those other crops is a vital tool in using diversification as a risk management tool. We assess the suitability of producing sweet potatoes as a way to manage farm income risk through enterprise diversification. We identify major crops that are produced in North Carolina to include cotton, hay, peanuts, soybeans, flue cured tobacco, wheat, squash, strawberries, tomatoes and sweet potatoes. We then derive the annual revenues per acre for each crop as the product of the per acre yield and price per unit for each of the last 15 years. The correlation coefficients between the revenues per acre between sweet potatoes and each of the other crops are estimated. The correlation coefficients between sweet potatoes and the other crops range from -0.002 for squash, and 0.79 for hay. After squash, the next lowest correlation coefficient is between sweet potatoes and snap beans at 0.29 while that with peanuts is 0.47. These results indicate that farm operations in North Carolina that include sweet potatoes and squash could reduce farm revenue risk without substantially reducing the level of revenue.

Seedling Zoysiagrass Response to Fluazifop-butyl and Trifloxysulfuron-methyl With the Safener Metcamifen - Hannah Wright-Smith
Influence of Demethylation Inhibiting Fungicides on Creeping Bentgrass Putting Greens - Wendell Hutchens
Endophytic N Fixing Bacteria Isolated From Warm-season Turfgrasses and Common Lawn Weeds - Andrea F Arevalo Alvarenga
Mowing Mediated Root Radial Transport of Lead in Cynodon dactylon (L.) Persoon - Xinyi Cai
Cool-season Turfgrass Biomass and Ecosystem CO2 Flux as Affected by Fertilization and Irrigation - Ruying Wang
The 2023 Arkansas Diamond Plant Evaluation Trials - Anthony Bowden

Managing grassy weeds in turfgrass can be challenging. In 2023 a new formulation of trifloxysulfuron-methyl containing the safener metcamifen, Recognition® Herbicide, was commercially available for use in established zoysiagrass. When applied as a mixture, this product safens zoysiagrass from the effects of the graminicide fluazifop-butyl (Fusilade® II Herbicide), allowing for higher application rates of fluazifop-butyl to manage difficult to control grass weeds such as bermudagrass. Previous research has demonstrated acceptable response following this herbicide mixture when applied to established zoysiagrass, however no information is available evaluating seedling zoysiagrass response to these herbicides. Experiments were conducted at the Milo J. Schult Agricultural Research and Extension Center in Fayetteville, AR and the Southwest Research and Extension Center in Hope, AR in 2023 to evaluate seedling zoysiagrass injury from applications of fluazifop-butyl and trifloxysulfuron-methyl with metcamifen applied at two different rates. “Zenith” zoysiagrass was seeded in June and August in Fayetteville and Hope, respectively, with herbicide applications made 2-and 4-weeks after emergence. Similar response was observed from both 2- and 4- week after emergence herbicide application timings. When applied as a mixture to seedling zoysiagrass, treatments of fluazifop-butyl plus trifloxysulfuron-methyl with metcamifen resulted in a maximum of 20% visual injury 1-week after treatment. However, seedling recovery was observed at subsequent ratings with

Demethylation inhibiting (DMI) fungicides are frequently applied to turfgrasses for suppression of many common fungal diseases in turfgrass. However, certain DMI fungicides cause phytotoxic effects to turfgrasses, particularly creeping bentgrass (Agrostis stolonifera L.), during the heat of the summer. A study was conducted in Fayetteville, AR in the summer of 2023 to determine the effects of nine DMI fungicides (flutriafol, mefentrifluconazole, metconazole, myclobutanil, propiconazole, prothioconazole, tebuconazole, triadimefon, and triticonazole) compared to a nontreated control on a ‘Pure Eclipse’ creeping bentgrass putting green. All treatments were applied a total of six times at the highest labeled rate at biweekly intervals beginning on 23 Jun 2023 and ending on 1 Sep 2023. A CO2-pressurized backpack sprayer was used to deliver the treatments in a carrier volume of 814 L ha-1. Plots were assessed weekly for percent phytotoxicity (0-100%). Additionally, beginning on 27 Jul 2023, clippings were collected, dried, and weighed weekly until 24 Aug 2023. Data were averaged across all rating dates, subjected to analysis of variance, and means were separated using a Student’s t-test (p < 0.05). Propiconazole caused ≥ 36.7% more phytotoxicity than any other treatment. The only other fungicide treatments that caused greater phytotoxicity than the nontreated control were myclobutanil and triadimefon. Myclobutanil, propiconazole, and triadimefon were also the only treatments to increase clipping weights compared to the nontreated control. These data suggest that many DMI fungicides do not cause phytotoxic effects on creeping bentgrass putting greens during the summer with the exception of myclobutanil, propiconazole, and triadimefon.

The turfgrass industry has attempted to adopt market available N fixing bacterial strains to supply exogenous N requirements. However, turfgrass inoculations with market available N fixing strains have led to inconclusive results. Research on naturally occurring N fixers has mainly focused on abundance and diversity on roots and below ground soil. These ecological niches are known to be impacted by regular management practices of turfgrass which also interfere with the colonization rates of microorganisms. Therefore, the use of endophytic N fixing bacteria which are naturally present in turfgrasses such as bermudagrass, creeping bentgrass, and tall fescue is an attractive alternative regarding a higher microbial stability and potential of colonization. In this study we evaluated the culturing potential of N fixing bacteria from three turfgrass and three common weed species, assayed their potential to grow under different ammonium chloride (NH4Cl ) concentrations, and compared the isolates with the dominant taxa from a previous study in the community composition of N fixing bacteria in ‘CitrablueTM’ St. Augustinegrass [Stenotaphrum secundatum (Waltz)]. The plant biomass was collected from ‘CitrablueTM’, ‘Celebration’ bermudagrass [Cynodon. dactylon (L.)], ‘Empire’ zoysiagrass [Zoysia japonica (Steud)], goosegrass [Eleusine indica (L.) Gaertn], crabgrass [Digitaria sanguinalis (L.) Scoop], and bull paspalum [Paspalum setaceum (Michaux)]. The biomass was washed with water and surface sterilized using consecutive immersions in ethanol 75%, bleach 50%, and three rinses with ultrapure water. After sterilization, N fixers were isolated using a N free enrichment technique with Carbon Combined Media (CCM) and streaking on CCM solid plates. Taxonomy of the isolates was assigned using 16S and nifH Illumina miseq sequencing, consequently, the isolates were grown in liquid CCM with NH4Cl concentrations ranging from 100 uM to 0.001 uM. The isolates, Sphingomonas trueperi, Kosakonia radicitans, Herbaspirillum rubrisulbicans, Agrobacterium salinotolerans, Stenotrophomonas maltophilia, Kosakonia oryzae, Enterobacter sp. were not able to grow below 1 uM of NH4Cl in liquid CCM, however, these strains were the best performing strains because were able to grow at lower NH4Cl concentrations. Lastly, the isolates were not genotype specific to either turfgrasses or weeds and were not correlated with the dominant taxa of N fixers on the ‘CitrablueTM’ study.

Moderate mowing has been demonstrated as an effective strategy for aiding soil Pb remediation using bermudagrass. However, the precise mechanisms by which mowing facilitates the absorption and transport of Pb in bermudagrass remain unclear. Radial transport of Pb in roots governs the amount of Pb loaded into xylem vessels, where Pb ions are translocated upward into shoots. This study aims to investigate the radial transport pathways and their characteristics of Pb in bermudagrass under Pb and mowing treatments to elucidate the underlying mechanisms. The results indicate a shift in Pb distribution within the bermudagrass roots under mowing treatments. Specifically, there was a decrease in Pb distribution in the root apoplast accompanied by an increase in the root symplast. Under mowing conditions, the synthesis of abscisic acid and jasmonic acid in roots was significantly induced, leading to a delayed development and deposition of the endodermal barriers (Casparian strips and suberin lamellae). This reduction in the contribution rate of the apoplastic bypass inhibited Pb from entering the stele via the apoplastic pathway. Conversely, mowing pretreatment inhibited Pb absorption in roots but promoted Pb absorption in shoots under treatments with metabolic and ion channel inhibitors. Additionally, Pb2 net influx in the root apex was remarkably enhanced, and the expression of Pb absorption- and transport-related genes (CdNramp5 and CdHMA2) were upregulated following mowing application, suggesting that mowing promoted Pb transport through the symplastic pathway. Overall, this study provides the first evidence that mowing mediates the radial transport of Pb in bermudagrass. Mowing enhances the absorption and root-to-shoot transport of Pb primarily by increasing the efficiency of the symplasmic pathway.

Concerns about the environmental impacts of lawns, including a high climate footprint, can pose challenges to the acceptance of natural turfgrasses. There are limited assessments of how to enhance turfgrass carbon sequestration and reduce management inputs in turfgrass systems in the northwest U.S. The goal of this study was to evaluate how fertilization and irrigation management can affect the ability of mixed cool-season turfgrass stands to sequester carbon. Annual rates of 0 and 196 kg N ha−1 were evaluated in the fertilization trial, while a non-irrigated control and 0.6 cm of precipitation applied four times per week in the summer months were compared in the irrigation trial. A portable clear chamber with a CO2 gas analyzer was used to measure CO2 fluxes. Grass clippings were collected from each plot to measure dry weight and subsequently returned to their respective plots. Clipping data were summarized as annual clipping production rates. Turfgrass standing biomass was sampled in 2021 and 2022 after summer stress and separated into aboveground (verdure) and belowground (thatch and roots) biomass. Our results indicated that the annual fertilization rate of 196 N ha−1 significantly increased photosynthesis in cool-season turfgrass in the winter and early spring compared to the unfertilized control. Fertilization also increased the net ecosystem exchange (NEE) rate in the winter, but the increases in NEE were less frequently observed than in the photosynthetic rate. Moreover, higher respiration rates were occasionally observed with the fertilization treatment. In contrast, fertilization had little to no effect on NEE, photosynthesis, and ecosystem respiration rates during the summer. Fertilization resulted in higher annual clipping yield, whereas there were no statistical differences between fertilization and no fertilization treatments in above- or below-ground biomass. In the irrigation study, the growth of turfgrass without irrigation ceased during summer as evidenced by reduced photosynthetic rates that were close to 0. Summer irrigation also stimulated ecosystem respiration which offset the benefits of enhanced photosynthetic rates, suggesting that further research is needed to identify the optimum irrigation practice for enhancing net CO2 assimilation. Irrigation produced greater annual clipping production in 2021 but had no effect in 2022. Irrigation was also shown to significantly increase aboveground biomass, but belowground biomass was not affected by irrigation. These results provided a better understanding of cool-season turfgrass growth in the Pacific Northwest U.S. so that cultural practices can be refined for more climate-friendly turfgrass management.

Arkansas’ research-backed plant assessment initiative known as "Arkansas Diamonds" aims to educate local gardeners on annual bedding plants that consistently thrive in Arkansas's climate. Moreover, it serves to bolster local growers and independent garden centers within the state. Facilitated by the Arkansas Green Industry Association (ARGIA) and the University of Arkansas System Division of Agriculture (UADA), this collaborative effort engages county agents across Arkansas in annual demonstration plots. In 2023, thirty county agents partook in the statewide evaluation of four annual plant species. Each agent received nine replicants of each species and conducted monthly measurements of height, width, flower quality, and overall health. These findings, integral to the selection process, contribute to designating certain plants as "Arkansas Diamonds," signifying their suitability for the state's gardens and green industry. After evaluations, the selected plants are grown by ARGIA members and marketed on a statewide basis to encourage home gardeners and the landscape industry to incorporate these plants into their home landscapes and support the local green industry and independent garden center within the state.