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Drought and salinity affect turfgrass growth and development adversely. Plant growth-promoting microorganisms (PGPMs) have been shown to have the capability of improving resistance to biotic stressors in plants. The objective of this research was to determine the efficacy of six commercial PGPMs on enhancing the drought and salinity resistance of kentucky bluegrass (Poa pratensis). The six PGPMs evaluated were Beauveria bassiana (strain GHA), Bacillus subtilis (strain GB03), Azadirachtin, Bacillus firmus (strain 1-582), Trichoderma harzianum Rifai (strain T-22) combined with Trichoderma virens (strain G-41), and Bacillus subtilis (strain QST713). Three cultivars—Kenblue, Moonlight, and Waterworks—were seeded in the greenhouse. Two-week seedlings were exposed to saline (sodium chloride at 6 dS⋅m–1 three times per week) or drought (tap water once per week) conditions, and no stress (irrigated with tap water three times per week) for 4 weeks. Results show that drought and salinity inhibited turf growth, with the greatest reduction in root dry weight (50.3% in drought conditions and 31.4% in saline conditions). ‘Kenblue’ performed better than ‘Waterworks’ and ‘Moonlight’ in all growth indices except for root length. Beauveria bassiana and B. subtilis had a similar or better result in enhancing turfgrass growth and development compared with the untreated turf under stress. Our results suggest that certain PGPMs have the potential to improve abiotic stress resistance in turfgrass.

Open Access

Turfgrass seed, a living organism, is facing more stringent trade regulations compared with nonliving products. We applied multiple empirical approaches to explore the impact of these regulations on trade flows in grass seeds. We constructed a series of novel variables to measure these regulations, such as environment regulation stringency, pre-shipment inspections, market conditions, and product requirements. Our results showed that nontariff trade measures had substantial impacts on the trade of grass seeds. These measures sometimes worked as barriers to trade and at other times worked as catalysts for trade.

Open Access

Promalin (Valent BioSciences, Libertyville, IL, USA) is a proprietary mixture of gibberellin A4 + 7 and 6-benzyladenine that is widely used in apple production to improve the fruit shape, size, and skin quality. Promalin typically increases fruit size and length. However, the increased growth likely increases the strain in the fruit skin, which may exacerbate microcracking of the cuticle and, consequently, russeting. This study aimed to monitor the growth-stimulating effect of Promalin in three different regions of fruits and investigate whether Promalin affects cuticular microcracking via effects on the deposition of cuticular components or via the accumulation of strain in the cuticle. Four Promalin sprays (20 mg⋅L 1) were applied to runoff; the first was applied at full bloom, and the remaining sprays were applied at approximately weekly intervals thereafter. Fruit surface areas and fruit surface area growth rates of the Promalin-treated fruits were higher than those of the untreated control fruits. Promalin increased the fruit length, but it had no effect on the fruit equatorial diameter. In Promalin-treated fruits, the base of each sepal extended, thickened, and became fleshy as early as 15 days after full bloom (DAFB). Allometric growth analyses revealed higher constant differential growth ratios of the pedicel and calyx length (before 36 DAFB) in Promalin-treated fruits than in control fruits. After 36 DAFB, the difference in constant differential growth ratios between Promalin-treated fruits and control fruits decreased. Cuticle mass per unit area increased with time in all regions of the fruit surface and was slightly (+3.3%) but significantly higher in fruits treated with Promalin than in control fruits. Additionally, the biaxial strain release was slightly and significantly lower in Promalin-treated fruits than in control fruits. When the isolated, cuticle was ablated from the inner surface and dewaxed, strain relaxation in the control fruits was higher than that in the Promalin-treated fruits. It was concluded that Promalin treatment increases the length of the fruit by increasing the lengths of the pedicel and calyx regions early during fruit development. Promalin only slightly increased cuticle deposition and fixation of cuticular strain. Promalin had no effects on microcracking or russeting.

Open Access

Whitefly-transmitted viruses have emerged as a major threat to cucurbit production in the United States during the past several decades. Cucurbit chlorotic yellows virus (CCYV), Cucurbit yellow stunting disorder virus (CYSDV), and Cucurbit leaf crumple virus (CuLCrV) are the main arthropod-borne plant viruses in cucurbit crops, including yellow squash (Cucurbita pepo). Symptoms of these viruses include interveinal chlorosis, chlorotic spots, yellowing, and curling of the leaves. The evaluation of specific viruses affecting a plant is challenging because of the prevalence of mixed infections in naturally infected fields. To devise an efficient breeding-based management approach, two PI lines (PI 171625 and PI 171627) were screened in a greenhouse to assess their resistance to individual infections of CCYV and CuLCrV. These lines were compared against a susceptible cultivar Gentry in two separate trials. PI 171627 displayed delayed symptoms, a reduced virus load, and a smaller area under the disease progress curve (AUDPC) compared with PI 171625 and susceptible cultivar Gentry when the plants were infected with CCYV. However, the AUDPC for CuLCrV was the same for both genotypes and the commercial line. Accession PI 171627, which displayed delayed and milder symptoms, could potentially provide a source for resistance against CCYV for breeding program. Future research is needed to comprehend the underlaying mechanism to understand this response.

Open Access

We analyzed the floral morphology and nectar production of several cultivars and species of Monarda representing five cultivars and four species grown in Georgia Piedmont and Montane regions. Over the course of two seasons, we detected significant differences among the samples in terms of inflorescence size, petal lobe and corolla widths and lengths, and total sugar content. M. didyma had larger glomerules, longer corollas and petal lobes, and higher nectar volume and total sugar content per flower. M. fistulosa and M. punctata had smaller glomerules, corolla and petal lobe lengths, and total sugar content per flower. Petal lobe and corolla length strongly correlated with sucrose and nectar production. Combined with data on horticultural performance, these results could be valuable in informing breeding goals for conservation-oriented landscape plants.

Open Access

Rapid leaching of soluble nitrogen (N) sources in soil poses a significant challenge in agricultural practices. Therefore, gaining a comprehensive understanding of crop responses to slow-release N application rates has become crucial to contributing valuable insights to optimize N management strategies in agriculture. A field study was conducted to investigate the influence of preplant calcium cyanamide fertilizer on the growth, yield, quality, and shelf life of short-day onion. Six levels of calcium cyanamide (CaCN2, 19.8% N), 0, 90, 120, 200, 400, and 600 kg⋅ha−1 CaCN2, which are equivalent to 0, 17.82, 23.76, 39.6, 79.2, and 118.8 kg⋅ha−1 N, respectively, replicated four times were broadcasted and incorporated into the top 5 to 10 cm of soil. Using 400 kg⋅ha−1 of CaCN2 yielded noteworthy improvements in various parameters of onion growth, such as plant height, leaf count, bulb weight per plant, bulb diameter, bulb length, and overall plant weight, as indicated by the study results. The application of different levels of CaCN2 as an N source exerted a significant influence on these growth factors. Moreover, the study revealed a direct correlation between CaCN2 application levels and the storage life of onions. Specifically, the findings demonstrated that the application of 400 kg⋅ha−1 CaCN2 resulted in enhanced yield and overall onion plant growth. However, the application of 600 kg⋅ha−1 CaCN2 increased the incidences of bulb weight loss, rots, and sprouting during the 8-week storage period at room temperature. These findings provide valuable insights for onion investors and farmers in the region and offer practical recommendations for optimizing fertilizer use and storage practices to improve onion production and minimize postharvest losses.

Open Access

Both natural turfgrass and synthetic turf fields have distinct advantages and disadvantages and present unique challenges. The challenges evolve over time because of climate change, players’ ever-changing needs, and the development of technologies. It is imperative to identify these challenges and devise effective solutions to overcome them. We conducted a survey of 97 administrators and managers from various organizations in the United States who were responsible for managing community sports fields. Our findings identified budget constraints as the biggest challenge for natural turfgrass field management, followed by issues related to use/scheduling and weather/climate. For synthetic turf field management, the top three challenges included budget constraints, use/scheduling, and other challenges (mainly safety issues). Additionally, administrators and managers consistently indicated increased funding as a solution for addressing challenges of both natural turfgrass and synthetic turf field management. We discuss the implications of these findings and provide potential ways to address these challenges.

Open Access