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Green spaces comprising natural turfgrass are ubiquitous in urban areas globally and allow for a variety of ecosystem services that benefit nature and people. However, traditional natural turfgrass is often critiqued for the number of inputs (e.g., fertilizer, water) required to maintain it. With those critiques in mind, some cities have turned to artificial turf as an alternative groundcover despite environmental and human health concerns (e.g., heavy metal leaching, volatile organic compounds). Research of artificial turf has been minimal compared with that of the growth of installations, especially related to social aspects of the surface. The current research used an in-person experiential case study of park visitors in the Twin Cities Metropolitan Area of Minneapolis–St. Paul, MN, USA, to investigate how individuals perceived artificial turf compared with natural turfgrass as it relates to potential uses (e.g., resting/relaxing) and beliefs about sustainability (e.g., environmental impacts). Overall, participants preferred natural turfgrass across all uses but two (recreational and organized sports). The largest differences were observed for the use for picnic areas and the use for play areas for pets. Participants also perceived natural turfgrass as more sustainable than artificial turf, corresponding to the contribution to human health and well-being. In contrast, participants equally perceived the use of these surfaces in terms of natural resources. These findings have implications for public land managers, urban planners, city councils, and other stakeholders because they consider the adoption of artificial turf or other possible alternatives (e.g., low-input turfgrasses, bee lawns) to traditional turfgrass in the communities and their sustainability, maintenance, and cost-savings.
Current economic conditions demonstrate the need for disease-resistant, highly productive pecan (Carya illinoinensis) cultivars for the southeastern United States that can generate high yield potential and can be produced at a reduced cost to enhance grower profit margins. The objectives of this study were to evaluate the performance of the pecan cultivars Lakota, McMillan, and Excel in the humid growing region of the Coastal Plain of Georgia, USA, in the absence of fungicides. In addition, recognizing the excessive nut production of ‘Lakota’, we evaluated the response of ‘Lakota’ to mechanical fruit thinning. Four trees each of ‘Lakota’, ‘McMillan’, and ‘Excel’ were selected randomly for sampling. Trees within this orchard block receive no fungicide applications. Pecan scab (Venturia effusa) was not observed on any cultivar evaluated throughout the study. Powdery mildew (Microsphaera alni) was observed on all cultivars, but was significantly greater on ‘McMillan’ in 2020 and 2022 as a result of drier conditions in those years. Based on current data, all three pecan cultivars evaluated during this study are suitable for commercial production; however, ‘Lakota’ and ‘Excel’ performed best under these conditions in terms of nut yield. There was no consistent difference in nut weight among cultivars. ‘Lakota’ has the greatest potential in terms of percent kernel, averaging 58% kernel compared with 49% and 52%, respectively, for ‘Excel’ and ‘McMillan’. However, in years of excessive cropping, percent kernel of ‘Lakota’ is reduced significantly. Mechanical fruit thinning increased the following year’s production of ‘Lakota’ by 82% over nonthinned trees.
Root-zone temperature (RZT) is an indispensable environmental factor for the proper growth and development of plants. Low RZT is one of the major limitations for agricultural production during cold seasons. In this study, the physiological responses of tomato seedlings to low RZT stress (10 °C) and its recovery were investigated with hydroponic cultivation in an artificial climate-controlled chamber. The stress reaction of tomato seedlings was evaluated by combining various indexes, including photosynthesis, chlorophyll fluorescence, root activity, hydrogen peroxide, and antioxidants. The results showed that low RZT adversely affected root activity, and in response to the limited root-source water and mineral elements, supply for shoot metabolism, leaf photosynthesis, and chlorophyll fluorescence were negatively influenced, which led to inhibited leaf area development and biomass accumulation. Hydrogen peroxide (H2O2), malondialdehyde (MDA), and proline accumulated with the time of low RZT stress. When restored to normal temperature (∼20 °C), the physiological parameters recovered to a certain degree, although most parameters were not at a similar level with the control. In crop production during cold seasons, it is necessary to improve the RZT to achieve high quality and yield production.
In the floriculture trade, cut pepper (Capsicum annuum) stems are typically grown for their fruit to add color contrast to the foliage and blossoms of conventional floral arrangements. Stems are commonly stripped of foliage because leaves wilt rapidly. Three divergent plant types and commercial hydration protection spray products were evaluated to identify effective vase life treatments and new pepper lines that combine both fruit and foliar interest with an acceptable postharvest cut stem life. Three inbred US Department of Agriculture pepper breeding lines with a tall vigorous growth habit and black foliage were selected for evaluation as cut stems. Line 190-2 produced upright, tabasco-like fruit; 191-1 produced upright, clustered, round fruit; and 196-1 was fruitless. Three commercial spray treatments Crowning Glory (FLCG), Finishing Touch, and Aqua Finish Clear (AFC) were evaluated on treated cut stems stored at 10 and 23 °C. The pepper breeding line had the greatest influence on cut stem foliage and fruit vase life. The fruitless line, 196-1 exhibited an extended vase life in comparison with fruited lines. Cold storage extended the vase life of cut stems. FLCG reduced foliage vase life at 23 °C, and AFC extended foliage vase life of the fruitless line 196-1. Relative to foliage, fruit exhibited greater resistance to desiccation, with glossier fruit of 191-1 desiccating more rapidly than fruit of 190-2. Similar trends were noted when cut stems were stored at 10 °C for 7 days and moved to 23 °C. However, in 2022 trials, the vase life of 190-2 was shortened, and those of 191-1 and 196-1 were extended, highlighting the influence of preharvest factors on vase life. The results demonstrate that cut stems of new pepper lines with vigorous upright growth habits and black-pigmented foliage, together with diverse fruit morphology, provide innovative possibilities for stunning cut flower arrangements.
A mobile web application called PropG was developed for students to quickly access more than 270 glossary terms defined in a plant propagation textbook. The functionality and usefulness of the app was evaluated by 53 students enrolled in a semester-long online course in plant propagation. Means of pre- and post-test responses to 17 knowledge items showed students perceived a significant knowledge gain in the course for each of the subject categories evaluated. Most students agreed or strongly agreed this learning tool was organized and easy to navigate and would use it in the future. Since 2021, PropG received 153,645 total page views, 90,818 unique visits, and 17,216 returning visits, showing its widespread use in plant propagation.
Widespread outbreaks of tomato powdery mildew (Leveillula taurica and Oidium neolycopersici) are problematic in fresh market tomato (Solanum lycopersicum) crops in western Oregon, USA. In western Oregon, fresh market tomatoes are frequently grown in greenhouses or high tunnels where conditions can promote diseases such as powdery mildew. Heightened concerns about worker safety limit the pesticides available for use in enclosed systems. We studied the efficacy of ultraviolet-C (UV-C) light applications under high-tunnel conditions compared with a standard fungicide program. Plants treated with UV-C had zero incidence of powdery mildew on all sample dates in the first trial. In trial 2, disease incidence was lower on UV-C treated plants than both grower standard and nontreated control early in the study while disease severity remained lower in UV-C than nontreated control and similar to grower standard treatment. Additional research is needed to optimize UV-C treatment intervals to minimize negative effects on plant growth and maximize powdery mildew control.
The citrus industry in Florida faces a destructive endemic disease, known as huanglongbing (HLB), associated with Candidatus Liberibacter asiaticus (CLas), a phloem-limited bacterium, and transmitted by the Asian citrus psyllid (ACP). Rootstocks are regarded as critical to keep citrus production commercially viable and help trees cope with the disease. Although most scions are susceptible, some rootstocks are HLB-tolerant and may influence ACP infestation and CLas colonization and therefore the grafted tree tolerance. This study aimed to elucidate the relative influence of rootstock and scion on insect vector infestation and CLas colonization under natural HLB-endemic conditions. Seven commercial rootstock cultivars with different genetic backgrounds were grafted with ‘Valencia’ sweet orange (Citrus sinensis) or were self-grafted (non-‘Valencia’) and planted in an open field where ACP and CLas were abundant. ACP infestation was determined weekly during periods of leaf flushing, and leaves and roots were analyzed every 3 months to determine CLas titers. Trees with ‘Valencia’ scion were more attractive to the psyllids than non-‘Valencia’ scions. This was also associated with a higher number of bacteria and a larger abundance of foliar HLB symptoms. The influence of the rootstock on the psyllid attraction of grafted ‘Valencia’ scion was less evident, and leaf CLas titers were similar regardless of the rootstock. Among the non-‘Valencia’ scions, Carrizo had the lowest and US-942 the highest leaf CLas titers. Root CLas titers also varied among cultivars, and standard sour orange roots harbored more bacteria than some trifoliate orange hybrid rootstocks such as US-942. In some trees, CLas was detected first in the roots 4 months after planting, but root CLas titers remained low throughout the study. In contrast, leaf CLas titers increased over time and were considerably higher than root titers from 7 months until the end of the study, 15 months after planting. Overall, the results of this study demonstrate a greater relative influence of the scion than the rootstock on ACP infestation and CLas colonization during the early stages of infection. This suggests that other cultivar-specific traits, such as the ability to tolerate other stresses and to absorb water and nutrients more efficiently, along with influences on the scion phenology, may play a larger role in the rootstock influence on the grafted tree tolerance during the later stages of HLB progression.
Most lake, canal, and pond management programs in the United States use herbicides labeled for aquatic use because many of these products, which are registered by the US Environmental Protection Agency, are relatively inexpensive and can effectively control undesirable plants without excessive damage to desirable species. Managers of these resources have expressed an interest in alternative methods for aquatic weed control that could reduce the use of traditional synthetic herbicides. We studied the effects of acetic acid and d-limonene on growth of the invasive aquatic species rotala (Rotala rotundifolia) and crested floatingheart (Nymphoides cristata), as well as on the native wetland plants spatterdock (Nuphar advena) and giant bulrush (Schoenoplectus californicus). We applied acetic acid and d-limonene (alone and in combination) once as foliar treatments to healthy plants, then grew out the plants for 8 weeks after treatment to observe damage resulting from treatments. We also evaluated diquat dibromide at three concentrations as “industry-standard” synthetic treatments for comparison. A 0.22% concentration of diquat dibromide eliminated most or all vegetation of rotala, crested floatingheart, and giant bulrush, but was much less damaging to spatterdock. Single-product applications of acetic acid or d-limonene had little effect on any of the four species evaluated. Some combinations of acetic acid and d-limonene provided acceptable control of rotala and selectivity on spatterdock and giant bulrush, but no treatments reduced crested floatingheart growth by more than 40%. Treating rotala with acetic acid and d-limonene instead of diquat dibromide would result in a 25-fold increase in material costs, which would make this option unaffordable for most aquatic system managers.
Integrated pest management (IPM) is an important component of golf course maintenance and includes conventional chemical pesticide use as well as nonchemical cultural management practices. Determining how frequent pest management practices are used on golf courses is critical when developing educational and outreach programs. The objective of this study was to determine the frequency of pest management practices and pesticide mixing and storage facilities on US golf courses. A survey was sent to 14,033 operational US golf facilities with 10% responding. Reliance on all conventional chemical pesticides increased from 2015 to 2021. The reliance on biological control products declined to 14% and reliance on the nonpesticide practice of using plant growth regulators remained equivalent to 2015. The most common pest management practices included monitoring weather patterns and scouting for pests, with 93% of golf facilities reporting the use of both. The use of written IPM and pesticide application plans increased from 44% to 63% of golf facilities between 2015 and 2021, respectively. Generally, mixing and storage facilities remained unchanged from 2015 to 2021. US golf facilities continue to use nonchemical pest management practices, but reliance on chemical pesticides has increased.
Magnolias (Magnolia sp.) are economically important woody ornamental plants; however, plant damage associated with frost and powdery mildew (Microsphaera alni and Phyllactinia corylea) disease is a major production challenge. To understand the tree architecture and powdery mildew resistance, 26 yellow-flowering magnolias (Magnolia sp.) were evaluated in McMinnville, TN, USA (USDA Plant Hardiness Zone 6b). One-year-old containerized trees were planted in a field plot during Mar 2006, with 4.6-m plant-to-plant and 3.7-m row-to-row spacing. The experiment was a completely randomized block design with three single-plant replications. Plant height and canopy diameter were measured on Dec 2016 and Feb 2018, and the apical dominance ratio (i.e., indicating tree architecture) was calculated by dividing the height by the canopy diameter. Plants were evaluated for powdery mildew severity and defoliation using a scale of 0% to 100% of the total plant canopy affected or defoliated, respectively, from Aug to Oct of 2016 and 2017. The area under the disease progress curve (AUDPC) was calculated for the evaluation period of each year. The plant apical dominance ratio ranged from 1 to 3, with ‘Gold Cup’ and ‘Sun Spire’ having the highest value, and ‘Lois’, ‘Gold Star’, ‘Golden Gala’, ‘Solar Flair’, ‘Stellar Acclaim’, ‘Sun Ray’, ‘Sunburst’, and ‘Sundance’ having the lowest value (i.e., relatively round shape). Of the 26 cultivars, Sundance, Sun Spire, Sun Ray, and Gold Cup had the lowest powdery mildew severity (10% to 33% in 2016 and 40% to 60% in 2017), AUDPC, and defoliation. Cultivars Anilou, Gold Star, Golden Pond, Golden Rain, Golden Sun, Green Bee, Honey Liz, Judy Zuk, Koban Dori, Lois, Solar Flair, Stellar Acclaim, and Yellow Bird were highly susceptible to powdery mildew (>80% disease severity) and had the highest AUDPC values. Results of this research may aid breeders, nursery producers, and landscapers when selecting yellow-flowering magnolia cultivars with desirable tree architecture and resistance to powdery mildew.