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Tall fescue (Schedonorus arundinaceus) offers an alternative to kentucky bluegrass (Poa pratensis) for use on athletic fields. Tall fescue has the ability to withstand athletic field traffic, but little is known about the best management practices such as optimal height of cut (HOC). A 2-year study was conducted on established ‘Snap Back’ tall fescue grown over a native soil root zone to determine optimal HOC under simulated athletic field traffic. Plots were maintained at various HOC treatments (1.5, 2, or 3 inches) for the duration of the growing season. Twenty-five simulated traffic events were applied each fall with a modified Baldree traffic simulator. The percentage of green cover (GC) loss per traffic event by HOC varied between years. In 2017, the 1.5-inch HOC improved traffic tolerance (–1.7% GC per event) compared with the other HOC treatments (–2.6% GC per event) in terms of percentage of GC. In 2018, the HOC did not have an impact on traffic tolerance. Differences in traffic tolerance between years could be a result of differences in precipitation (78 mm in 2017, 6 mm in 2018) during the period when traffic occurred, which suggest that the lower HOC performs better under wet conditions compared with the greater HOC. There were no differences among treatments for the safety variables measured (surface hardness, rotational resistance, and soil moisture).

Open Access

In controlled environments, supplementing a light spectrum with ultraviolet A (UVA; 315–399 nm) or blue (B; 400–499 nm) light increases the concentrations of phenolic compounds that can increase quality attributes, such as leaf pigmentation and nutritional quality of lettuce (Lactuca sativa). However, B light and sometimes UVA light can inhibit leaf expansion and biomass accumulation when continuously applied, whereas applying it only at the end of the production cycle can increase lettuce quality with little to no effect on crop yield. Our objective was to quantify the persistency of periodic supplemental UVA or B light and compare end-of-production with continuously applied supplemental light during indoor lettuce production on quality attributes and biomass accumulation. We hypothesized that supplemental UVA or B light would be more effective later, rather than earlier, during production with increasing lettuce quality attributes. We grew ‘Rouxai’ red-leaf lettuce hydroponically at an air temperature of 23 °C under 75 μmol⋅m−2⋅s−1 of red (peak = 664 nm) plus 75 μmol⋅m−2⋅s−1 of warm-white light provided by light-emitting diodes. The supplemental lighting treatments consisted of adding 30 μmol⋅m−2⋅s−1 of UVA (peak= 386 nm) or B (peak = 449 nm) light during the seedling phase (P1; days 4–12), growth phase (P2; days 12–20), finishing phase (P3; days 20–28), or the entire time (ET; days 4–28). Supplemental UVA or B light applied at any individual phase did not inhibit biomass accumulation, whereas enriched B light during the entire production period inhibited fresh mass compared with no supplemental light. Additionally, supplemental UVA or B light during P3 or ET similarly increased total phenolic and anthocyanin concentrations. Finally, applying UVA or B light during P1 or P2 had no residual effect on mature plant growth or quality at harvest. We concluded that the end of the production cycle is the optimal time to apply supplemental UVA or B light to improve lettuce coloration and phenolic content, that earlier application elicits transient responses, and that continuous application improves lettuce quality but inhibits biomass accumulation. Finally, there are potential energy savings by using end-of-production supplemental light compared with continuous application of the same spectrum.

Open Access

Understanding preferences and challenges of home gardeners is valuable to the consumer-horticulture industry. Citizen scientists in Florida were recruited to grow compact tomato (Solanum lycopersicum) plants started from seed, as transplants, or as flowering plants in a 16-week experiment. Participants, who had various gardening experience levels, were provided with a kit containing all materials needed to grow plants to maturity. Project engagement was encouraged with monthly online meetings and a social media page. A survey was delivered at the end of the project and completed by 117 participants. The survey aimed to evaluate participants’ preferences, challenges, and experiences with each plant product. Plants started as seed or as flowering plants were equally preferred among participants and were rated higher than transplants. However, participants were least satisfied with the yield, rate of plant growth, fruit taste, and care required to grow plants started from seed. Ninety-one percent of participants said they would be willing to pay more for flowering plants than for transplants. Across plant products, pests and flower/fruit drop were reported as challenges by up to 85% and 18% of participants, respectively. Results from this study highlight the potential of using citizen science to assess gardening experiences and preferences, which can support stakeholders who cater to the consumer-horticulture industry.

Open Access

Pumpkins (Cucurbita sp.) are currently sold in retail commercial bins categorized based on fruit size. There are no standards for these fruit sizes, thus creating discrepancies across the industry. Furthermore, there is not a published partial budget analysis for pumpkin fruit yield based on plant area. An observational study was conducted to quantify and standardize the fruit sizes of pumpkins packed into commercial bins. These proposed standardized fruit sizes were then correlated to the expected fruit size and quantity of different plant areas to estimate the total commercial bin yield. Additionally, a partial budget analysis was conducted to calculate the greatest profit per hectare with the varying plant areas. Pumpkins from bins labeled medium, large, extra-large, and jumbo were hand-measured to determine the diameter, length, and weight. Based on a discriminate analysis, 20% of pumpkins were incorrectly sorted based on current practices. The proposed standard fruit diameters for each bin size are as follows: medium, 23.5 to 26.8 cm; large, 26.9 to 29.9 cm; extra-large, 30.0 to 33.6 cm; and jumbo, 33.7 to 35.5 cm. The results of a partial budget analysis showed that the most profitable plant spacing area is 0.9 m2 with a 1.5-m row width, which will earn $37,163/ha. Profit for pumpkin production is contingent on both fruit quantity and fruit size because these factors dictate the quantity and category of commercial bins. Growers should consider both metrics to optimize their operation.

Open Access

Candidatus Liberibacter asiaticus (CLas), which causes huanglongbing (HLB) in citrus trees, has a great impact on tree root health, fruit development, and juice quality. HLB-affected trees have a fibrous root density loss of ∼30% to 80%, resulting in the limited capacity of citrus trees to uptake nutrients. Therefore, this study was conducted for 3 years to 1) assess the temporal changes in root density as a result of varied fertilization, 2) determine dynamics of HLB with regard to root growth and distribution as a result of varied fertilization for Valencia orange trees, and 3) evaluate the impact of varied fertilization rate and method of fertilization on fruit yield for HLB-affected trees. Macronutrients and micronutrients were applied at varying fertilization rates (0×, 1×, 2×, and 4×, of University of Florida guidelines). Root scans were done using minirhizotrons at 0 to 19.1 cm, 19.1 to 40.7 cm, 38.2 to 59.8 cm, and 57.3 to 78.9 cm soil depths. Results obtained from the study showed that root growth and distribution were greater in 0 to 19.1 cm than 19.1 to 40.7 cm to 57.3 to 78.9 cm soil depths. Thus, root growth decreased (P < 0.0004) with increasing soil depth due to variation in nutrient availability for tree uptake. Increased nutrient availability at occurrence of physiological processes in citrus trees also influenced root growth and distribution, resulting in root growth flushes in the months of Nov to early Feb and Jul to early Aug. Fruit yield was significantly different between treatments in 2 of the 4 years of the study (P = 0.001 and P = 0.003), and largely ascribed to soil fertilization of micronutrients compared with foliar. Therefore, at higher fertilization rates, particularly via soil application, nutrient availability was increased, thus promoting root growth and distribution and fruit yield in HLB-affected orange trees.

Open Access

Eating watermelon (Citrullus lanatus) is a traditional part of the Fourth of July holidays in the United States; however, growing watermelon in Missouri, USA for the local Fourth of July market requires an early growing season start (beginning of April) under protected culture because of low temperatures and the risk of freezing. Therefore, ‘Yellow Doll’ watermelon production was investigated under low tunnel (LT) and caterpillar high tunnel [HT (walk-in movable two-row tunnel)], and the economic feasibility was assessed by marginal analysis for both protected cultures. Planting in early April allowed harvest to start 1 to 2 weeks before the target market date. In addition, yield increased under HT in comparison with LT and open field (Op). Marginal analysis under the conditions of this study and prices obtained from local farmers’ markets showed a positive marginal rate of return for HT in comparison with the control Op. The marginal rate of return sensitivity study suggests that differences in marketable yield of 300–400 and 200–250 lb/1200 ft2 are necessary under HT and LT, respectively, for the protected culture to be economically feasible with watermelon prices above $0.75/lb and/or $1.00/lb as obtained in local farmers’ markets. Therefore, it is possible and there is potential to produce watermelon under protected culture for the local Fourth of July market. A gain in market share with potential premium prices for watermelon may increase the sustainability of small and medium-size specialty crop farmers in Missouri. To accomplish this, it is necessary to use early cultivars (70 to 80 days to maturity), plant in early April with transplants grown in greenhouses, and make sure to manage tunnels properly to maintain favorable growing conditions, protect against freezing temperatures and ensuring good pollination.

Open Access

Biochar is considered an environmentally friendly potting mix ingredient because it sequesters carbon, and its biomass can be obtained from renewable resources. If the biomass is obtained from the undesirable eastern redcedar (Juniperus virginiana), then it has the additional benefit of helping to curtail its spread and protect natural habitats. If consumers recognize this benefit, then they may be willing to pay a premium for potting mix made from eastern redcedar biochar. This study used an internet survey of potting mix customers to measure the size of this potential premium. The results showed that consumers were willing to pay $2.42/ft3 more for potting mix containing 20% eastern redcedar biochar (by weight). This premium was even larger for respondents who were aware of the weedy nature of eastern redcedar.

Open Access