You are looking at 81 - 90 of 41,731 items for
Jujube (Ziziphus jujuba Mill.) is also called Chinese date. There are ∼100 jujube cultivars with limited commercial availability, and the majority of them have scant details in the United States. In this study, nutrient dynamics during fruit maturation of different jujube cultivars grown at Las Cruces, Los Lunas, and Alcalde, NM, were examined in 2018 and 2019. Cultivars varied by location and year, and included ‘Li’, ‘Lang’, ‘Sugarcane’, ‘September Late’, and ‘Sherwood’. Parameters tested were total phenolic content (TPC), proanthocyanidins (PAs), vitamin C, cyclic adenosine monophosphate (cAMP), and antioxidant capacity: 2,2-diphenylpicrylhydrazyl radical scavenging capacity and ferric reducing antioxidant potential (FRAP). Moisture, TPC, PAs, FRAP, and vitamin C content decreased with fruit maturity; however, the latter stage of fruit maturity showed an increase in cAMP. Compared with fruit at full-red maturity, creamy fruit had TPC, PA, FRAP, and vitamin C concentrations that were 1.0 to 1.8, 4.4 to 12.4, 1.9 to 2.6, and 0.1 to 1.3 times higher, respectively, depending on location (P < 0.05). From creamy to full-red maturity, cAMP increased by 0.9 to 4.5 times. At full-red maturity, estimated TPC in jujube fruit ranged from 10.6 to 16.8 mg gallic acid equivalent per gram dry weight (DW), whereas estimated PAs ranged from 1.8 to 5.3 mg PA B2/g DW. Jujube fruit at full-red maturity had a vitamin C content that ranged from 649.0 to 1153.3 mg/100 g DW. At full-red maturity, the concentration of cAMP ranged from 148.1 to 277.6 μg/g DW in Las Cruces samples.
A primary goal of undergraduate education is to provide a comprehensive and diverse educational experience to prepare and promote student success in their professional and personal pursuits. Increased academic success and program connectivity have been demonstrated when undergraduate students are engaged in research early in their degree programs. Despite the known benefits of undergraduates engaging in research, there are challenges associated with conducting undergraduate research programs. Reported barriers include the lack of student knowledge about research methods, lack of preparedness, and lack of student identification and understanding of their specific interests which may not facilitate research ideas and affinity to conduct research. Additional challenges are related to the lack of faculty resources (e.g., time, specific equipment, research space, etc.), the ability to train and supervise undergraduates who may have very limited or no research experience and those students who are true beginners lacking foundational skills. Moreover, involving, engaging, and supporting underrepresented students (e.g., first-generation college students, females, ethnic minorities) in undergraduate research experiences can require different approaches for mentors to be effective. The “Engaging Undergraduate Students in Research” workshop was organized by the Vice Presidents of the American Society for Horticultural Science (ASHS) Research and Education Divisions at the ASHS 2022 Annual Conference in Chicago, IL, USA. The workshop featured three speakers who described their experiences engaging undergraduate students in research. After each speaker provided comments for ≈5 minutes, the workshop attendees self-selected into three breakout groups with the speakers for roundtable discussions related to engaging students in research through coursework, engaging students via formal research projects, and engaging underrepresented students in research. After the breakout group discussions, a summary was given by each group, and whole group discussions and comments were facilitated. This is a summary of the information discussed and shared during the workshop, along with information that can assist faculty with developing and implementing undergraduate research experiences.
As a result of virus disease, producers have to renew passion fruit plantlets every year to ensure yield and fruit quality in Taiwan. Currently, the entire procedure—from the preparation of rootstock seeds to having plantlets ready for planting—may take ∼3 months. The shortage of grafted plantlets in internal and foreign markets is a continuous challenge for the industry. The objective of this study is to improve the production mode to establish a rapid production system of grafted plantlets. The results show that the germination rate and time of rootstock seeds improved remarkably at 30 °C. The final germination rate was 100% within 10 days on average. Application of a complex chemical fertilizer Hyponex No. 4 solution, diluted 1000-fold, by soil drench weekly resulted in seedlings ready for grafting 28 days after treatment. Stem diameter reached 2.5 mm and plant height was ∼10 cm. After grafting, keeping the plantlets at 25 °C with a relative humidity of more than 85% ensured all incisions were healed within 7 days. After moving the plantlets to a semishaded greenhouse for hardening, and maintaining the same temperature and relative humidity for another 7 days, the propagation process was complete. Compared with double-node and shoot-tip scions, the growth and plantlet height of the single-node scion were not the best. However, considering the convenience of scion acquisition and the high rate of propagation, the use of a single-node scion is recommended. It takes only 56 days to propagate grafted plantlets, which is 1 month less using current processes.
Successful weed control before seeding is necessary for proper turfgrass establishment. However, herbicide labels differ in the time required between application and seeding. The objective of this research was to determine the influence of four postemergence broadleaf combination herbicides on tall fescue (Festuca arundinacea) cover, normalized difference vegetation index (NDVI), and canopy height when seeded 0, 3, 7, and 14 days after herbicide application. Herbicide treatments included the following: 1) a nontreated control; 2) 0.03 lb/acre carfentrazone-ethyl + 0.09 lb/acre methylchlorophenoxypropionic acid (MCPP) + 1.44 lb/acre 2,4-dichlorophenoxyacetic acid (2,4-D) + 0.30 lb/acre dicamba; 3) 0.20 lb/acre fluroxypyr + 0.01 lb/acre halauxifen-methyl + 1.44 lb/acre 2,4-D choline; 4) 0.20 lb/acre triclopyr + 0.003 lb/acre pyraflufen-ethyl + 1.72 lb/acre 2,4-D + 0.14/acre dicamba; and 5) 0.04 lb/acre penoxsulam + 0.04 lb/acre sulfentrazone + 0.40 lb/acre 2,4-D + 0.11 lb/acre dicamba. Penoxsulam + sulfentrazone + 2,4-D + dicamba reduced tall fescue cover, NDVI, and canopy height compared with the nontreated. This research demonstrates seeding between 0 to 14 days after an application of carfentrazone-ethyl + MCPP + 2,4-D + dicamba, fluroxypyr + halauxifen-methyl + 2,4-D choline, or triclopyr + pyraflufen-ethyl + 2,4-D + dicamba will result in successful tall fescue establishment under the conditions evaluated in these experiments.
Understanding plants’ response to different irrigation levels is essential for developing effective irrigation scheduling practices that conserve water without affecting plant growth and yield. The objective of this study was to evaluate the responses of three sweet corn (Zea mays var. saccharata) cultivars 1170, 8021, and Battalion under three irrigation levels (50%, 75%, and 100%). Irrigation treatments were based on soil moisture management allowable depletion. Replicated trials were conducted, in an open field using 1-gal containers, at the Tropical Research and Education Center, Homestead, FL. A drip system with microsprinklers was used for irrigation. Daily crop evapotranspiration (ETc) rates were measured using a digital scale based on differences in weights of soil containers and plants. Reference evapotranspiration (ETo) was calculated using the FAO-Penman-Monteith equation. Crop-coefficient (Kc) values for the three cultivars were calculated from measured ETc and calculated ETo. In addition, leaf area, stomatal conductance, and fresh biomass were measured. Total irrigation amounts corresponding to the 50%, 75%, and 100% treatments were 116, 162, and 216 mm, and total ETc values were 128, 157, and 170 mm, respectively. The two deficit irrigation treatments (50% and 75%) resulted in a reduction of ETc for the three cultivars compared with the 100% irrigation treatments. Results also showed that under 75% and 100% treatments, Kc values were usually greater than 1 for the three cultivars and reached as high as 1.5. Additionally, leaf area and fresh biomass weight in the 50% treatment were mostly lower than in the 75% or 100% treatments.
Vaccinium meridionale (section Pyxothamnus), a tetraploid species native to higher altitude locations in Jamaica, Colombia, and Venezuela, is of interest to Vaccinium breeders for its profuse, concentrated springtime flowering and monopodial plant structure, both of which may be useful in breeding for mechanical harvest. In this study, tetraploid V. meridionale was hybridized successfully as a male with 4x V. macrocarpon (section Oxycoccos, American cranberry). The first-generation hybrids with 4x cranberry were intermediate in morphology and notably vigorous. The 4x F1 hybrids displayed a vining plant structure, increased flower bud numbers, and white campanulate flowers. The F1 hybrids displayed modest fertility as females upon selfing and backcrossing to 4x V. macrocarpon. Evaluations of male fertility found good pollen production and a range of pollen quality ranging from very good to poor. Hybrids functioned well as males in crosses that used US 1930, a V. meridionale–V. vitis-idaea hybrid as the female. The fertility suggests that these hybrids, despite being derived from intersectional crosses, might be used conventionally in cranberry breeding without significant difficulty.
Pansy (Viola ×wittrockiana) is a greenhouse crop commonly grown under black shade net; it often requires the use of chemical plant growth regulators to maintain a compact growth habit. Nonchemical efforts to alter plant morphology, such as height, would provide a more sustainable solution than chemical application. The objective of these studies was to evaluate the effects of different colors of shade nets on controlling growth and flowering of pansy. In Expt. 1, ‘Clear Yellow’, ‘Buttered Popcorn’, and ‘Deep Orange’ pansy plugs were placed under 30% blue or black shade net or, as a control group, where grown with no shade net. In Expt. 2, the same three cultivars of pansy were grown under 50% black, red, pearl, or aluminized shade net. Data were collected on plant height, plant width, flower number, plant survival, soil plant analysis development chlorophyll meter (SPAD) readings, and light quality. In Expt. 1, the blue shade net reduced height to flower and height to leaves, but also decreased flower number and plant survival as compared with black shade net. All plants under no shade died. In Expt. 2, SPAD, an indicator of plant quality by estimating leaf greenness, was found to be lower under black shade net, whereas pearl shade net led to a decrease in plant height and no effect on the number of flowers. Light quality, including red-to-far-red ratio, varied among shade treatments, whereas light intensity was reduced under aluminized, black (50%), and red shade nets compared with other shade treatments. Blue and pearl shade nets both reduced plant height, but blue shade net also reduced plant survival and flowering.
Chlorine is a disinfectant commonly used to treat water. The United States Environmental Protection Agency (USEPA) has set a standard limit of up to 4 mg·L−1 chlorine for drinking water. The objective of this project was to identify chlorine phytotoxicity thresholds on ‘Rex’ lettuce (Lactuca sativa) when the water source contained chlorine levels within the USEPA standard limits. The nutrient solution to grow lettuce was prepared with reverse osmosis–treated water treated with 0, 0.5, 1, 1.5, 2, and 4 mg·L−1 chlorine and then fertilizers were added. Lettuce plants were grown in a deep-water culture hydroponic system. Visual toxicity symptoms on leaves, relative leaf greenness, and fresh and dry biomass were measured. Our results indicate that irrigation water sources with ≥1 mg·L−1 chlorine used to prepare nutrient solutions can cause phytotoxicity in lettuce plants in just 3 days. Compared with the untreated control, lettuce shoot biomass was lower by 30%, 55%, 66%, 83%, and 92% at 0.5, 1, 1.5, 2, and 4 mg·L−1 of chlorine, respectively. Water sources with ≥ 1 mg·L−1 chlorine can cause significant marketable yield reduction in lettuce grown in deep-water culture.