Pecan (Carya illinoinensis) has high kernel antioxidant activity and unsaturated fatty acid content, which contribute to its nutraceutical properties. In the western United States, where soils are typically alkaline, pecan trees require frequent zinc (Zn) fertilizer applications to maintain normal canopy growth and nut production. Our objective was to investigate the effects of tree Zn fertilization on nutraceutical properties of ‘Wichita’ and ‘Western’ pecan kernels. Trees were fertilized with ethylenediaminetetraacetic acid (EDTA) chelated Zn, which was applied to the soil at one of three seasonal rates for a total of three treatments: 0 (control), 2.2, or 4.4 kg·ha−1 Zn. Nut samples were collected and homogenized for analyses of kernel oil yield, hydrophilic antioxidant capacity, fatty acid profile, and γ-tocopherol content. Although soil Zn treatments did not significantly affect antioxidant capacity of defatted pecan kernels, Zn application had significant positive effects on both total kernel oil yield and γ-tocopherol content compared with the control. In conclusion, soil application of Zn fertilizer may increase the human health-promoting aspects of pecan kernels, a valuable attribute among health-conscious consumers.
Yuqing Wang, Richard J. Heerema, James L. Walworth, Barry Dungan, Dawn VanLeeuwen, and F. Omar Holguin
Roy D. Flanagan III, Jayesh B. Samtani, Mikel Ann Manchester, Stephanie Romelczyk, Charles S. Johnson, Watson Lawrence, and Jeremy Pattison
Strawberries (Fragaria ×ananassa) are one of the major high-value crops in North America. There is increasing interest in commercial strawberry production for local markets in Virginia and surrounding states, but information on the performance of newer cultivars is extremely limited. We tested 10 commercially available June-bearing cultivars [Benicia, Camarosa, Camino Real, Chandler, Strawberry Festival, Flavorfest, FL Radiance, Treasure, Sweet Charlie, and Winterstar™ (FL 05-107)] and two day-neutral cultivars (Albion and San Andreas) for their spring and summer fruiting capacity in Virginia production systems in a randomized, replicated study, at three on-farm locations. Data were collected on vegetative growth, yield performance, fruit quality, sweetness, and fruit diameter. Cultivars with the highest total yields averaged across all three locations were Benicia, Camino Real, Chandler, and Camarosa. ‘Camino Real’ had the highest marketable yield at all three locations, not significantly different from ‘Chandler’, and ‘Benicia’ and ‘Camarosa’ had the highest marketable yield at two of the three locations. ‘Flavorfest’ and ‘Sweet Charlie’ had the highest total soluble solids concentration for the harvest season. Overall, for all locations, ‘Benicia’ and ‘Camino Real’ had the largest fruit diameter, and ‘Strawberry Festival’ had the smallest fruit diameter.
Coleman L. Etheredge and Tina M. Waliczek
In the United States there has been a push to convert industries to a more environmentally sustainable business attitude in recent years. Environmentally sustainable practices are not only good for the environment, but there is increasing evidence these practices lead to an increase in customer loyalty. The trend of self-regulation, willingly imposing more stringent environmental policies than required by the government, is progressing toward a time where environmentally friendly practices will be a competitive necessity for businesses to survive. The main purpose of this research was to investigate the perceptions of environmental health of retail flower shop owners and their willingness to recycle fresh cut floral waste produced at retail flower shops for use as compost and to determine if there is a statistical correlation between environmental awareness and willingness to compost fresh cut flower waste. A mailing list of retail florists from across the United States was compiled. A total of 1974 florists from all 50 states were sent a standardized e-mail explaining the purpose of the study. Embedded in the e-mail was a hyperlink that redirected willing respondents to the survey. Each person on the mailing list was emailed one time. Of the 300 retail florists who took part in the survey, a majority, 190 (63.33%), were ranked as having “high concern” for environmental health. A majority of florists 247 (82.33%) “agreed” or “strongly agreed” to collaborate with Master Gardener programs and other organizations if it meant they could recycle their floral waste through composting. Through the creation of industry- and state-sponsored certifications, florists could brand and promote their business as more environmentally conscious by composting their floral waste. This could possibly, in turn, stimulate sales and increase profit margins while having the added benefit of reducing the amount of waste entering landfills.
Luis O. Duque
Sweetpotato (Ipomoea batatas) production in Pennsylvania and the northeastern United States has been increasing steadily. The performance of eight commercially available sweetpotato varieties and two unreleased accessions grown on raised beds and covered with black plastic mulch in Pennsylvania was evaluated. All varieties and accessions were evaluated in 2 successive years (2018 and 2019) at Rock Springs, PA. There were statistically significant differences in total marketable yield (TMY), but not in all yield components in both years. ‘Orleans’, ‘Beauregard’, ‘Averre’, and ‘Covington’ consistently produced high marketable yields and suitable U.S No.1 grade storage roots. ‘Bonita’ (tan skin/white flesh) and ‘Carolina Ruby’ [red skin/orange flesh (OF)] produced consistent yields in both years (range, 330–430 bushels/acre; 50-lb bushel). NC413 [purple skin (PS)/purple flesh (PF)] produced the lowest yield in 2018 and was discarded for future trials. In 2019, NCP13-0030 (PS/PF) produced good yields and shapes comparable to OF varieties. Overall total yields (TYs) measured in this study compared satisfactorily with average nationwide yields, with several varieties producing more than 500 bushels/acre.
Francisco E. Loayza, Michael T. Masarirambi, Jeffrey K. Brecht, Steven A. Sargent, and Charles A. Sims
This study investigated the effect of ethylene treatment at high temperatures of 30 to 40 °C for up to 72 hours on subsequent ripening-associated processes in mature green ‘Sunny’ and ‘Agriset 761’ tomatoes (Solanum lycopersicum). Compared with ethylene-treated fruit at 20 °C, ethylene exposure at 30 or 35 °C stimulated ripening in terms of ethylene biosynthesis and color development, but the ethylene effect was only apparent after transfer to air at 20 °C. There were no negative effects on ripe tomato quality related to ethylene exposure at 30 or 35 °C. However, ethylene production of tomatoes was permanently impaired by ethylene exposure at 40 °C for 48 or 72 hours even after transferring fruit to air at 20 °C; these fruit exhibited slow softening and color development. Our results suggest that tomatoes perceive ethylene at 30 to 35 °C despite impairment of ripening at those temperatures, with the accelerated ripening response becoming apparent only after transferring the tomatoes to air at lower temperature.
Hanah T. Rheay, Kevin Lombard, Catherine Brewer, and F. Omar Holguin
Neomexicanus hops (Humulus lupulus var. neomexicanus) are receiving increased attention within the craft beer and nutraceutical industries. Characterization of bittering acids and essential oils in two neomexicanus varieties revealed wide ranges of bittering acid compositions and distinct essential oil profiles compared with ‘Cascade’ common hops (H. lupulus). Total phenolic content (TPC), expressed as gallic acid equivalent (GAE), in neomexicanus hops ranged from 50 to 100 mg·g−1 GAE, consistently higher than published literature values for hop TPC (2 to 50 mg·g−1 GAE). Results indicate that, compared with ‘Cascade’, neomexicanus hops have unique phytochemical characteristics, which may lead to new applications in brewing and nutraceutical fields.
Rachel P. Naegele and Mary K. Hausbeck
Phytophthora capsici causes root and fruit rot and foliar blight of pepper. Multiple sources of resistance to Phytophthora root rot have previously been identified, but most display only partial resistance. One source, CM334, has broad spectrum root rot resistance to multiple pathogen isolates but has only low to moderate fruit rot resistance. This study evaluated previously identified pepper lines for resistance to two P. capsici isolates, OP97 and 12889, and compared root rot resistance to fruit rot resistance and genetic structure. CM334 was confirmed as a broad spectrum resistance genotype, whereas all other sources of resistance evaluated were susceptible to infection by one or both isolates evaluated. Although not completely resistant, PI 566811 displayed moderate resistance to fruit and root rot to both P. capsici isolates. Fruit rot resistance had a significant but small to moderate positive correlation (r = 0.26–0.63) with root rot resistance depending on the isolate and length of exposure. Pepper accessions with resistance to Phytophthora root and fruit rot belonging to different genetic subpopulations were identified and could serve as candidates for partial-resistance loci to incorporate into pepper breeding programs.
Chyun-Chien Liang, Tzu-Yao Wei, and Der-Ming Yeh
Neoregelia cultivars have been used in many areas for landscaping and indoors in a variety of creative ways, but scientific reports of their pollination and hybridization are presently limited. Cross-combinations of Neoregelia cultivars were created to define conditions for pollination timing and to evaluate cross-compatibility. Neoregelia cultivars have short-lived flowers. Hybrid seeds were obtained only when cross-pollination was performed before 1200 hr. Results of 19 cross-combinations including six reciprocal crosses revealed that hybrid seeds were obtained in the female parents with a 1.9- to 2.0-cm style length, but not in those with a 2.6- to 3.0-cm style length. The pollen tube penetrated the ovule as early as 1 day after pollination in the compatible cross, whereas swollen pollen tubes were observed at half and two-thirds of the style in the incompatible cross. Removal of 50% of the style length of the female parents could overcome the fertilization barrier for those incompatible crosses and hybrid seeds could be successfully obtained.
Gregory E. Frey, Tarik Durmus, Erin O. Sills, Fikret Isik, and Marcus M. Comer
Shiitake (Lentinula edodes) is an edible mushroom-producing fungus. “Natural log-grown” shiitake mushrooms are favored by consumers and are often produced by small farmers and hobbyists in the United States. The tree species most often recommended as a substrate for shiitake is white oak (Quercus alba), which has many other economic uses. We tested two strains of shiitake in log substrates of three common, low-value tree species in the southeastern United States to identify potential alternatives to white oak. We found that sweetgum (Liquidambar styraciflua) was a good substitute for white oak, both in terms of mushroom production and financial returns. Red maple (Acer rubrum) had less potential, with lower production and marginal financial returns, and ailanthus (Ailanthus altissima) was not a suitable alternative substrate. Of the two shiitake strains tested, a commercially available strain performed better than a naturalized strain that was isolated from an uninoculated log. Further research is needed to identify other potential alternative substrates and production techniques in the southeastern United States and other regions.
Ved Parkash and Sukhbir Singh
Salinity stress is among the major abiotic stresses prevailing in arid and semiarid areas such as the southern high plains of the United States. In these areas, both declining quality of groundwater and cultivation practices have resulted in increased accumulation of salts in the root zone. The occurrence of excessive salts in the root zone is detrimental for plant growth and economic yield. Recently, biochar has received a great consideration as a soil amendment to mitigate the detrimental impacts of salinity stress. However, the effectiveness of biochar to mitigate the salinity stress depends on the feedstock type, pyrolysis temperature and time, soil type and properties, and plant species. Therefore, a pot experiment in a greenhouse was conducted to 1) examine the effects of salinity stress on physiology, shoot and root growth, and yield of eggplant (Solanum melongena L.), and 2) evaluate the potential of hardwood biochar and softwood biochar to mitigate the damaging effects of salinity stress on eggplant. The experiment was conducted in a split-plot design with three salinity levels of irrigation water [S0 (control, 0.04 dS·m−1), S1 (2 dS·m−1), and S2 (4 dS·m−1)] as main-plot factor and three biochar treatments [B0 (control, non-biochar), Bh (hardwood biochar), and Bs (softwood biochar)] as subplot factor with four replications. Results showed that stomatal conductance (g S) and photosynthesis rate decreased significantly, while leaf temperature and electrolyte leakage increased significantly with increase in irrigation water salinity levels. Root growth (root length density and root surface area density), shoot growth (plant height, stem diameter, and leaf area), and yield of eggplant declined with increase in levels of salinity stress. Biochar application helped to enhance g S and photosynthesis rate, and to decrease leaf temperature and electrolyte leakage in leaf tissues of plants. This resulted in better root growth, shoot growth, and fruit yield of eggplant in treatments amended with biochar than non-biochar (control) treatment. There was no significant difference in the effect of two types of biochars (hardwood and softwood biochar) on physiology, root growth, shoot growth, and yield of eggplant. Therefore, it can be concluded that softwood and hardwood biochars could be used to minimize the detrimental impacts of salinity stress in eggplant.