ASHS 2025 Conference

Investigating novel sensing solutions is important for improving the existing phenotyping pipeline. Polarization is strongly correlated with the geometric properties of an object, such as surface roughness and its orientation relative to the sensor or light source. It has the potential to detect leaf wilting and quantify leaf angles in turfgrass, which are both crucial in precision turfgrass irrigation and crop coefficient determination. This study explores the integration of polarization imaging into RGB imaging pipelines for evaluating turfgrass responses to drought. A controlled dry-down was conducted on two zoysiagrass cultivars and two bermudagrass cultivars grown in pots. Polarization images, RGB images, and visual wilting ratings were collected daily during the four-day dry-down period. Leaf angles, both azimuth and zenith, were derived from top- and side-view RGB images, respectively. We analyzed polarization metrics, including the degree of linear polarization (DoLP) and the angle of polarization (AoP), to assess their relationship with drought stress indicators, such as wilting scores, low Excess Green Index (EGI) values, and changes in leaf angles. EGI and the standard deviation of AoP strongly correlated with wilting scores. Furthermore, DoLP values correlated with leaf zenith angle when the incident light angle was known.

Ornamental plants are essential components of both rural and urban landscapes, with the horticultural industry generating $2.01 billion in bedding and garden plant sales in 2019. However, increasing drought stress, affecting 99.3% of Utah in 2023, highlights the need for water-efficient landscaping. Water-wise landscaping offers a promising solution by conserving water while maintaining visual appeal, making it increasingly popular in arid and semi-arid regions. This study was to investigate the effects of deficit irrigation frequency on the morphological and physiological of 13 landscape plant taxa: Caryopteris ×clandonensis ‘Blauer Splatz’ (Sapphire SurfTM bluebeard), Cercis canadensis (eastern redbud), Cercis occidentalis (western redbud), Cotoneaster ×suesicusn ‘OSUCOT2’ (Emerald BeautyTM cotoneaster), Hesperaloe parviflora ‘Straight Up Red’ (‘Straight Up Red’ Texas red yucca), Miscanthus sinensis ‘NCMS2B’ (bandwidth maiden grass), Penstemon barbatus ‘Novapenblu’ (Rock CandyTM blue penstemon), Penstemon pinifolius (pineleaf beardtongue), Penstemon strictus (rocky mountain beardtongue), Physocarpus opulifolius ‘Diabolo’ (‘Diabolo’ ninebark), Physocarpus opulifolius ‘Little Devil’ (Little DevilTM ninebark), Rosa ×hybrida ‘Meifranjin’ (Blushing Drift® rose), and Vitex agnus-castus ×rotundifolia ‘Helen Froehlich’ (Summertime BluesTM vitex). The experiment was conducted at the Utah Agricultural Experiment Station’s Greenville Research Farm in North Logan, UT, from 1 Jun to 31 Oct 2024. Eight plants per species were randomly assigned to one of three irrigation frequencies based on reference evapotranspiration (ETo): high (80% ETo), moderate (50% ETo), and low (20% ETo). Overall plant appearance was evaluated biweekly using a visual rating scale from 0 (dead) to 5 (excellent). Plant growth, stomatal conductance, and canopy temperature were recorded monthly. Net photosynthetic rate, transpiration rate, and vapor pressure deficit were measured in August and September. Results indicate species-specific responses to deficit irrigation. Some species, such as P. barbatus and P. strictus, exhibited improved visual quality, lower canopy temperatures, and higher photosynthetic rates under more frequent irrigation. In contrast, other species were not affected by reduced irrigation frequency.

Horticulturists and landscape managers are often highly skilled professionals with an extensive understanding of plant biology and growth requirements. However, despite this knowledge, the post-construction soil conditions in which new landscapes are often installed can undermine the success of plantings. In the best-case scenario, horticulturists with passion and perseverance provide attentive management to the plants to help establish the landscape, but this process can often require a deep dive into soil science, an area that many horticulturists may not be equipped to handle fully. The issue of urban soil is gaining increased attention from soil scientists, but a greater integration of horticulture and urban soil science is essential. Similarly to how soil science and crop science are often interwoven, a more holistic approach is needed to bridge the gap between plant knowledge and urban soil conditions. This would better equip horticulturists and landscape professionals to manage the complexities of urban environments. A notable example of this challenge can be found in downtown Oklahoma City, where three large public gardens have been developed within a one-mile span. Each garden presents its own set of unique challenges, including varying soil types, management timelines, and irrigation sources. Myriad Gardens, established in 1970’s has soil that has been disturbed and modified since the early 1900’s. With a complete garden renovation in 2012, Myriad has an average soil pH range of 6.7-7.7. Upper Scissortail previously, an industrial neighborhood was established in 2019 and constructed utilizing seven different soil formulas. With 1000 newly planted trees, poor quality well irrigation water, and a soil pH over 8.0, plant establishing has been challenging for the staff. Finally, Lower Scissortail built in 2022 was also developed with five soil formulas and like Myriad is on city water that has shown to be a better source of water. This case study highlights the complexity of managing urban landscapes and underscores the importance of addressing soil issues at the onset. For horticulturists, it is no longer enough to possess plant knowledge alone. They must also understand the intricate soil dynamics that can make or break the success of a landscape.

Flower production in the Northeastern United States is experiencing a revival as consumer demand for locally grown flowers rises alongside increased interest in sustainable agriculture. However, growers in the region face persistent challenges, including a short and unpredictable growing season, limited land availability, high input and labor costs, and market saturation during peak months. This study draws from field interviews, survey data, and stakeholder engagement with flower growers, floriculture educators, and agricultural service providers across New England. It examines key production and marketing strategies that successful flower farms have adopted, including diversified cropping, succession planting, season extension, direct-to-consumer sales, and floristry integration. Additionally, this work highlights systemic needs in research, infrastructure, and technical assistance tailored to the ornamental crop sector. Findings emphasize the potential for expanded investment in floriculture education, cooperative distribution models, and grower networks to strengthen the viability of flower farming in the region. By elevating grower perspectives and showcasing practical innovations, this presentation contributes to the broader discussion on supporting ornamental crop producers through targeted outreach and research.

The Japanese maple scale (JMS) (Lopholeucaspis japonica) is an armored scale insect that causes significant losses in the ornamental industry through direct injury, plant rejection, unmarketable stock, increased pest control costs, and restricted interstate plant movement. Ornamental growers typically identify JMS by visually inspecting trunks, branches, and twigs for waxy covers or by using sticky tape traps to monitor crawler activity. However, its microscopic size and camouflaged appearance make early detection challenging. This study aims to develop an artificial intelligence (AI)-guided, on-the-go pest scouting system to address the current challenges in early management of JMS in ornamental crop production. To develop the scouting system, a Sony ILX-LR1 professional camera with a 61.0 megapixel full-frame sensor and interchangeable E-mount lenses designed for detailed industrial applications is used to capture high-resolution images. A small amount of data has been collected so far, with plans to gather a larger image dataset during the summer months. In the initial analysis, captured images were sliced into smaller patches to make the microscopic JMS detectable. These sliced images were used to train a transformer-based AI model for detecting JMS. The trained model, tested on the small dataset, showed it could detect JMS with an Intersection over Union (IoU) of over 0.8. While the model shows potential for detecting microscopic JMS, comprehensive training and testing with a larger dataset are needed to validate its performance. Upon completion, the developed scouting technology will serve as an effective tool for early detection and management of JMS in nursery environments, reducing plant injury and rejection while improving profits for ornamental growers.

Zoysiagrass is a popular choice for Florida lawns but requires supplemental fertilization and irrigation. Nitrogen-fixing bacteria, such as Azospirillum Brasilense (Azb), may improve nutrient uptake and rooting, potentially reducing fertilizer and irrigation needs. The experiment is taking place from Summer 2024 to Fall 2026 at the University of Florida, evaluates the effects of Azb on Zoysiagrass under varying nitrogen (N) and irrigation rates. The experiment uses ‘CitraZoy’ Zoysiagrass treated with three Azb products (Tazo-B, AzoPro Turf, Azo Root) and a non-inoculated control. Treatments are applied monthly at three N levels (100%, 50%, 0%) and two irrigation levels (100% and 75% recommended irrigation), using a randomized complete block design with four replicates per treatment. Weekly data collection includes normalized difference vegetation index (NDVI), visual quality, soil moisture, and digital image analysis. Statistical analysis is performed using ANOVA, with mean comparisons determined by Fisher’s Protected Least Significant Difference (LSD) at p ≤ 0.05. Results indicate that Azb products mitigate the impact of reduced irrigation on soil moisture. Combining Tazo-B or Azo Root with 50% N achieves an optimal balance of turf quality and sustainability. Additionally, Tazo-B with 100% N and 75% irrigation yields green cover comparable to fully irrigated treatments. These first-year findings suggest Azb enhances Zoysiagrass performance while reducing nitrogen and irrigation requirements. A second year of research will confirm these results, supporting the potential of Azb to improve turfgrass sustainability.

As climate variability increases and urban water demand rises, the turfgrass industry faces challenges in maintaining high-quality landscapes with limited irrigation. Water restrictions and escalating costs necessitate sustainable solutions to improve water efficiency without compromising turf performance. Research from the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has shown that compost incorporation can enhance soil structure, increase plant-available water, and potentially reduce irrigation needs for warm-season turfgrasses in Florida. While initial studies demonstrated benefits for new landscape installations, limited research exists on established lawns. Our study aims to evaluate the influence of compost and fertilizer applications under varying irrigation conditions on turfgrass quality. This study, conducted in 2023 and 2024 at the UF/IFAS Plant Science Research and Education Unit in Citra, Florida, examines the combined effects of compost and fertilizer applications under different irrigation regimes. The experimental design had six distinct management practices: a control with neither compost nor fertilizer; compost topdressing once per growing season; combined compost topdressing and fertilizer application once per season; compost topdressing twice per season; both compost and fertilizer applied twice per season; and fertilizer alone applied twice per season. Irrigation was applied at 50%, 75%, and 100% of UF/IFAS recommendations. Compost was applied at 0.5 yd³/1000 ft², and fertilizer at 1.0 lb N/1000 ft². Results from statistical analysis consistently demonstrated that compost topdressing combined with fertilizer twice per season (CTD

Preemergence herbicides play a critical role in weed management but can pose challenges for ornamental plant safety during establishment. Black-eyed Susan (Rudbeckia hirta) cv “Denver Daisy” is a popular ornamental cultivar valued for its vibrant blooms and adaptability. An experiment was conducted in 2024 at the Southwest Research and Extension Center in Hope, AR to evaluate transplanted Black-eyed Susan tolerance to topically applied S-metolachlor. S-metolachlor was applied as a broadcast application at 0, 2.8, 5.6, and 11.2 kg ai ha-1 two weeks after Black-eyed Susan plants were transplanted into raised beds. Visual injury, plant heights, and plant widths were collected at 2- and 4-weeks after application. There was no visual injury at any rating, however, some damage from deer feeding on plants was observed so only plant widths are reported. Plant widths ranged from 9 to 10.5 cm at 2-weeks after treatment and 15.7 to 17.3 cm at 4-weeks after treatment, with no differences between treatment at either data collection timing. Data from this study suggests that topically applied S-metolachlor may be a viable residual weed control option for ornamental Black-eyed Susan.

The landscape maintenance industry is under growing legislative scrutiny for its environmental and noise impacts. Among professional tools, the leaf blower is most frequently targeted due to its high decibel output and widespread use. In response, advancements in battery technology have introduced commercial-grade battery-powered alternatives. Despite this progress, many landscape professionals remain concerned about the work capacity and efficiency of battery-powered blowers compared to traditional gas-powered models. This study evaluated commercial gas and battery leaf blowers through controlled laboratory tests measuring runtime, task efficiency, output force, and sound levels. Results showed that some battery-powered models operated longer on a single charge than gas-powered blowers on a single tank of fuel. However, gas-powered blowers were 24% to 200% more effective in completing standardized tasks when operated by experienced users. This advantage stemmed from their ability to maintain high, consistent output throughout operation. In contrast, most battery-powered blowers sustained peak performance only briefly before throttling output to conserve energy, reducing their effective work capacity. Additionally, several battery models failed to meet manufacturer claims regarding output force. While battery blowers offered quieter operation—producing 20% to 26% lower decibel pressures than gas units—the performance tradeoffs remain a concern for high-demand applications. These results highlight the disparity between power sources in leaf blowers, one of the most frequently used tools in landscape maintenance, and emphasize the current limitations and tradeoffs involved in transitioning to battery-powered equipment under regulatory pressure.

Providing protection from winter elements and seasonal temperature shifts are important considerations for nursery growers and landscape contractors. Frost protection fabrics can provide additional insulation to sensitive plants by maintaining temperatures at more moderate thresholds; however, with a wide range of weights and materials on the market, it is necessary to understand the extent to which various frost fabrics can serve this purpose. Five frost cloth materials were evaluated over a three-month period (January through March 2025) at the LSU AgCenter Hammond Research Station, with individual landscape bed replicates covered with one of four different weights of a non-woven frost fabric, one woven frost fabric, or left uncovered. Landscape bed replicates were comprised of typical landscape bed media (i.e. aged pine bark and sand) with a steel edging frame and support hoops. Each replicate was provided with a temperature sensor below the bed surface and a temperature and light sensor at the bed surface. Sensors recorded temperature and light conditions every 30 minutes, providing insights towards ambient environmental conditions beneath the frost fabrics (or in open air) as well as within the landscape bed media. Uncovered plots received the most amount of light and were subject to the highest degree of variability in temperature; however, the frost protection fabrics provided varying degrees of light transmission and temperature moderation. The woven frost protection fabric allowed the greatest amount of light transmission for all frost protection fabrics investigated, where it also yielded higher surface and subsurface temperatures relative to non-woven materials and uncovered replicates. Non-woven frost fabrics of varying weights generally provided similar levels of insulation to each other; however, it was observed that heavier frost fabrics were capable of minimizing temperature fluctuations. All investigated frost fabrics were effective in raising the minimum surface and subsurface temperatures relative to the uncovered replicates. As the study (and spring season) progressed, peak temperatures under frost cloths were at times elevated above uncovered plots. The results indicate that frost cloths of various materials and weights provide different levels of insulation, and that careful attention to environmental conditions is necessary for deciding when to place and remove frost cloths in the field.