Browse
You are looking at 51 - 60 of 42,476 items for
Local variety trial data are necessary for informing growers how a specific variety might perform on their farm but there is a growing deficiency in these data, particularly for specialty crops. To address this issue, an online decision-support tool named the Vegetable Variety Navigator (VVN) was developed in 2020 to compile, analyze, and visually communicate publicly available broccoli (Brassica oleracea var. italica), cucumber (Cucumis sativus), and sweet pepper (Capsicum annuum) variety trial data. To validate the accuracy and predictive potential of the VVN, we conducted 16 on-farm variety trials for broccoli, cucumber, and sweet pepper between 2020 and 2022. Yield of each variety in a trial was compared with the mean of all other varieties in the same trial to calculate a mean relative yield (MRY). The difference between observed relative yield in the field and predicted relative yield from the VVN (ΔMRY) was used to assess the accuracy of three different VVN prediction strategies. Strategies included using data from the following: 1) the single geographically nearest trial, 2) the mean of the three geographically nearest trials, or 3) the mean of all available trial data regardless of location. Compared with random predictions of MRY for each variety (from within a normal distribution of MRY values in the VVN database), the VVN predictions reduced ΔMRY and improved the accuracy of relative yield predictions across varieties by up to 21% in broccoli, 51% in cucumber (depending on strategy), and 51% in sweet pepper. Results confirm the value of the VVN as a decision-support tool for growers facing an ever-increasing number of crop variety options with less variety trial data. Future research and development are needed to improve the accuracy of the VVN by accounting for possible effects of crop types, management, and location on relative yield and quality.
This study aimed to investigate the psychophysiological effects of horticultural activities on the prefrontal cortex (PFC) to understand how horticultural activities can influence mental health and cognitive function. This study involved 39 adults with an average age of 54.6 years (±12.5 years) and was conducted in a laboratory setting at Konkuk University. The impact of five different types of horticultural activities—sowing, transplanting, planting, harvesting, and packaging—on PFC oxyhemoglobin (oxy-HB) concentrations was assessed. Functional near-infrared spectroscopy (fNIRS) was used to measure oxy-HB levels in the PFC while participants engaged in each activity for 90 seconds. The results indicated that the overall PFC oxy-HB concentration was at its lowest during planting and at its highest during sowing (P < 0.001). In the right PFC, oxy-HB was also at its lowest during planting and at its highest during sowing (P < 0.01). In the left PFC, the lowest oxy-HB concentrations were observed during both planting and harvesting, whereas the highest oxy-HB concentrations were observed during transplanting and sowing (P < 0.001). Additionally, sex-based differences were noted, with females showing significantly lower oxy-HB concentrations during sowing (P < 0.05) and transplanting (P < 0.01) than those of males. These findings suggested that psychophysiological responses, as indicated by oxy-HB concentrations, vary depending on the type of horticultural activity and by sex.
Visual stimuli from green plants have positive effects on mental health. This study aimed to compare human responses to varying plant types [live, artificial, two-dimensional (2D), and three-dimensional (3D) plant models] as visual stimuli. Thirty adults (age, 29.9 ± 11.5 years) viewed each plant form while an electroencephalography (EEG) measured their brain activity. Psychological responses were assessed using the semantic differential method (SDM). No significant differences were observed among visual stimuli; however, brain activity differences varied between male and female participants. Males who observed live and artificial plants had a higher relative alpha (RA) spectrum (RAS) and relative fast alpha (RFA) spectrum frequencies at Fp1 and Fp2 (P < 0.05 and P < 0.01 vs. P < 0.05 and P < 0.01, respectively), indicating greater emotional stability. Similarly, male participants who viewed 2D models had higher RA and RFA frequencies at Fp1 (P < 0.01, P < 0.01) and Fp2 (P < 0.05, P < 0.01). Male participants who observed 3D models exhibited higher RA, RSA, and RFA frequencies at Fp1 (P < 0.01). Live and artificial plants were deemed the most calming (P < 0.01). Both sexes found live plants to be the most pleasant (males: P < 0.01; females: P < 0.05) and natural (males: P < 0.001; females: P < 0.01). Overall, alpha wave differences were not significant among plant types, and live plants elicited a trend toward emotional stability. These findings suggest that 3D plant models can be as effective as real plants in psychophysiological applications, indicating their potential benefits for enhancing mental health in urban environments.
The plant nursery industry in Oregon faces increasing challenges from climate change, particularly concerning the cultivation of shade trees grown in nursery production. Shade trees are multimillion-dollar agricultural commodity in Oregon, the number one producer of shade trees in the United States. Oak, maple, and sycamore are common examples of shade trees. Our hypothesis posited that despite being commonly cultivated together in shade-tree production blocks under similar management protocols, these trees employ distinct hydraulic strategies during growth. The aim of this research was to investigate the physiological response of Sunset Red Maple (Acer rubrum ‘Franksred’) and Red Oak (Quercus rubra) to variations in soil moisture and vapor pressure deficit (VPD). The research was carried out at the experimental field-grown nursery located at the North Willamette Research and Extension Center in Aurora, OR, USA. Stomatal conductance (g s) and stem water potential (ψs) were measured to assess plant responses to soil moisture and VPD. When soil moisture was abundant, average Red Oak g s was 0.26 ± 0.13 mmol·m−2·s−1, twice as great as Red Maple, at 0.12 ± 0.09 mmol·m−2·s−1. Red Oak g s was 2.67 times greater than Red Maple g s under soil moisture deficit. Similarly, at any given soil moisture content Red Oak ψs was significantly less negative (−6.22 ± 2.70 bars, n = 384) compared with Red Maple (−12.15 ± 4.45 bars, n = 384). In general, our results revealed distinct responses between the two species, with Red Maple exhibiting greater sensitivity to soil moisture and VPD compared with Red Oak. Furthermore, we observed an important correlation between VPD and maple g s, with g s, decreasing in response to increasing VPD whether soil moisture was abundant (R 2 = 0.64) or lacking (R 2 = 0.69), highlighting the importance of considering atmospheric moisture dynamics in plant water management strategies. These findings underscore the complexity of plant responses to drought and emphasize the necessity of informed water management practices for sustainable nursery production. This research contributes to our understanding of plant hydraulic physiology and provides valuable insights for sustainable nursery management practices, particularly in the face of climate change–induced droughts.
Indoor greening is becoming popular because it provides many benefits for people. However, plant selection for indoor greening is limited to shade-tolerant tropical plants internationally, and little research has been performed to expand the use of native herb plant species. The aim of this research was to study growth characteristics of Japanese native herbs under common light intensity regimes in office buildings. Eight species of Japanese native herbs (Acorus gramineus, Cameilla sinensis, Farfugium japonicum, Gynostemma pentaphyllum, Perilla frutescens var. crispa f. viridis, Petasites japonicus, Sasa veitchii, and Saxifraga stolonifera) were examined in an open growth chamber with light-emitting diode light tape under three light intensities [photosynthetic photon flux densities of 3 µmol·m−2·s−1 (250 lx), 6 µmol·m−2·s−1 (500 lx), and 12 µmol·m−2·s−1 (750 lx)] from 8 AM to 10 PM every day from Jun 2021 to Oct 2021 in an office. Farfugium japonicum and Saxifraga stolonifera were as shade-tolerant as typical tropical plants and grew well under all light intensities. Sasa veitchii performed well under high and medium light intensity. The other plant species require supplemental lightning to achieve sufficient growth indoors.
This study was conducted in a newly established (2-year-old) almond orchard to investigate the effects of five different mulching materials (woven and nonwoven fabric, black and white polyethylene, almond shell) and flame treatments applied at two different frequencies (FL20 and FL30) on weed control and almond growth compared with those of conventional herbicide (glyphosate) application and weedy control. Thus, this study included nine different treatments. The impacts of these treatments on weed density and coverage were periodically monitored. Additionally, the biomass of the weeds was measured at the end of the season to evaluate the effects of the treatments. Because the almond orchard was not yet in the economic fruit-bearing stage, the effects of the treatments were examined in terms of parameters that characterize almond growth, such as plant height, trunk diameter, shoot length, and shoot thickness. The chlorophyll content and water potential values of the trees were also determined. The results of this two-season study indicated that synthetic mulches provided the best outcomes in terms of weed control and almond growth. No weed emergence was observed throughout the season in any of the synthetic mulch treatments. Although almond shells used as organic mulch were highly effective for blocking sunlight, they failed to prevent the growth of some vigorously growing perennials such as Cynodon dactylon and Sorghum halepense that emerged from gaps. Flame treatments demonstrated rapid and effective results; however, they were less successful against the aforementioned monocot perennial weeds and required frequent repetition because of the lack of residual effects. Glyphosate, an herbicide that is commonly used in conventional orcharding, was applied five times throughout the experiment and proved effective weed management compared with that of the weedy control. However, considering the increasing herbicide resistance, environmental and health issues, and growing interest in organic almond cultivation, synthetic mulch applications have emerged as good options. Despite the initially higher establishment costs, synthetic mulches effectively controlled weeds and reduced water stress, thereby promoting almond tree growth.
The aim of this study was to establish a regeneration system of watermelon. Watermelon W1 was selected as the experimental material using seedling shoots as a receptor. The effects of different concentrations of 6-Benzylaminopurine (6-BA) on the shoot-tip of watermelon seedlings were studied. Number of shoots at the stem tip were counted every other day until the new buds reached 2 cm. The new stem tip was cut, and the effect of different concentrations of Murashige and Skoog (MS) medium on the number of regenerated roots and root length of shoots were studied. The results showed that the differentiation rate was highest when the 6-BA concentration was 0.7 mg/mL to 0.8 mg/mL. The optimum concentration for root regeneration was 1/8 MS. At this concentration, the number rooted was the highest, and root length was also promoted.
Pyroxasulfone is a very long chain fatty acid (VLCFA) inhibitor (group 15) with potential for preemergence weed control in orchard crops and would be beneficial for reducing selection pressure for resistance to more commonly used herbicides, such as glyphosate. Pyroxasulfone is registered and widely used in corn and soybeans in the United States as a solo product and in several premix formulations. However, there is limited published information on the performance and safety of pyroxasulfone in tree nut orchard systems. To assess the potential fit for pyroxasulfone in this crop sector, a series of crop safety and weed control efficacy experiments were carried out in key California orchard crops and in fallow fields with common orchard weeds. The non-crop studies were conducted near Davis, CA, to evaluate winter annual weed control with pyroxasulfone in comparison with pendimethalin and indaziflam. In addition, an irrigation incorporation experiment was conducted in summer to evaluate the effects of incorporation timing on pyroxasulfone, pendimethalin, and indaziflam efficacy as a measure of relative stability. Orchard weed control experiments were conducted in spring in an almond orchard near Arbuckle, CA, and a walnut orchard near Davis, CA. The orchard experiments included pyroxasulfone, pendimethalin, and indaziflam in various rate combinations with glufosinate. To evaluate crop safety, 2-year experiments were conducted to evaluate repeated applications of above-label rates of pyroxasulfone at 1199 g·ha−1 and S-metolachlor at 14,010 g·ha−1 on 1- to 2-year-old almond, pistachio, and walnut trees near Davis. Pyroxasulfone performed similarly to commercial standards with up to 95% control of broadleaf and grass weeds with pyroxasulfone and indaziflam providing 96% to 100% control of annual bluegrass, and pyroxasulfone (293 g·ha−1) being the only herbicide to suppress (>70%) common lambsquarters at 60 days after treatment (DAT). Other weeds controlled by pyroxasulfone include swinecress, redroot pigweed, yellow nutsedge, and Italian ryegrass. No differences were found among treatments in the incorporation timing study indicating adequate stability on the soil surface under summer conditions. Crop injury was not observed in the established orchards or the young orchard studies and there were no treatment effects on tree trunk diameter of almond, pistachio, and walnut in the 2-year crop safety experiments. These results indicate a potential for pyroxasulfone in California tree nut orchard systems that would be an additional site of action and beneficial for management of herbicide-resistant weeds in these crops.