This page has only limited features, please log in for full access.
A greenhouse study was conducted to assess the relative salt tolerance of 11 cultivars of hydrangea: Hydrangea macrophylla ‘Ayesha’, ‘Emotion’, ‘Mathilda Gutges’, ‘Merritt’s Supreme’ and ‘Passion’; H. paniculata ‘Interhydia’ and ‘Bulk’; H. quercifolia ‘Snowflake’; H. serrata ‘Preciosa’; and H. serrata × macrophylla ‘Sabrina’ and ‘Selina’. Plants were treated with a nutrient solution at an electrical conductivity (EC) of 1.0 dS·m−1, and nutrient solution-based saline solutions at an EC of 5.0 dS·m−1 (EC 5) or 10 dS·m−1 (EC 10). The study was repeated in time (Experiments 1 and 2). In both experiments, by the fourth week after treatment, ‘Bulk’ plants in EC 10 exhibited severe salt damage with most of them dead. ‘Interhydia’ was also sensitive, showing severe salt damage in EC 10 with a high mortality rate by the end of the experiment. The leaf area and total shoot dry weight (DW) of all cultivars in EC 5 and EC 10 treatments were significantly reduced compared to the control. Leaf sodium (Na+) and chloride (Cl−) concentrations were negatively correlated with visual quality, leaf area and shoot DW. The salt-sensitive cultivars ‘Bulk’, ‘Interhydia’ and ‘Snowflake’ had inherently low leaf Na+ and Cl− concentrations in both control and salt-treated plants compared to other cultivars. Salt tolerance varied among species and cultivars within H. macrophylla. Among the 11 cultivars, H. macrophylla ‘Ayesha’ and two hybrids, ‘Sabrina’ and ‘Selina’, were relatively salt-tolerant. H. macrophylla ‘Merritt’s Supreme’ and ‘Mathilda’ were moderately tolerant. H. paniculata ‘Bulk’ was the most sensitive, followed by H. paniculata ‘Interhydia’, and then by H. serrata ‘Preciosa’ and H. macrophylla ‘Passion’, as evidenced by high mortality and severe salt damage symptoms. H. quercifolia ‘Snowflake’ and H. macrophylla ‘Emotion’ were moderately salt-sensitive.
Genhua Niu; Youping Sun; Triston Hooks; James Altland; Haijie Dou; Christina Perez. Salt Tolerance of Hydrangea Plants Varied among Species and Cultivar within a Species. Horticulturae 2020, 6, 54 .
AMA StyleGenhua Niu, Youping Sun, Triston Hooks, James Altland, Haijie Dou, Christina Perez. Salt Tolerance of Hydrangea Plants Varied among Species and Cultivar within a Species. Horticulturae. 2020; 6 (3):54.
Chicago/Turabian StyleGenhua Niu; Youping Sun; Triston Hooks; James Altland; Haijie Dou; Christina Perez. 2020. "Salt Tolerance of Hydrangea Plants Varied among Species and Cultivar within a Species." Horticulturae 6, no. 3: 54.
Crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae) is an exotic pest species that causes aesthetic and economic damage to crapemyrtles and poses potential threats to other horticultural crops in the United States. Although previous studies reported the infestation of CMBS on several alternative hosts across multiple families in Asia, its potential threats to other documented alternative hosts remain elusive and yet to be confirmed. In this study, feeding preference studies of CMBS were conducted on forty-nine plant species and cultivars in 2016 and 2019, in order to gain insight into the expansion of CMBS distribution in the United States, as well as other regions of the world. The infestations of CMBS were confirmed on apple (Malus domestica), Chaenomeles speciosa, Disopyros rhombifolia, Heimia salicifolia, Lagerstroemia ‘Spiced Plum’, M. angustifolia, and twelve out of thirty-five pomegranate cultivars. However, the levels of CMBS infestation on these test plant hosts in this study is very low compared to Lagerstroemia, and may not cause significant damage. No sign of CMBS infestation was observed on Rubus ‘Arapaho’, R. ‘Navaho’, R. idaeus ‘Dorman Red’, R. fruticosus, B. microphylla var. koreana × B. sempervirens, B. harlandii, or D. virginiana.
Runshi Xie; Bin Wu; Haijie Dou; Cuiyu Liu; Gary W. Knox; Hongmin Qin; Mengmeng Gu. Feeding Preference of Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) on Different Species. Insects 2020, 11, 399 .
AMA StyleRunshi Xie, Bin Wu, Haijie Dou, Cuiyu Liu, Gary W. Knox, Hongmin Qin, Mengmeng Gu. Feeding Preference of Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) on Different Species. Insects. 2020; 11 (7):399.
Chicago/Turabian StyleRunshi Xie; Bin Wu; Haijie Dou; Cuiyu Liu; Gary W. Knox; Hongmin Qin; Mengmeng Gu. 2020. "Feeding Preference of Crapemyrtle Bark Scale (Acanthococcus lagerstroemiae) on Different Species." Insects 11, no. 7: 399.
Phenolic compounds in basil (Ocimum basilicum) plants grown under a controlled environment are reduced due to the absence of ultraviolet (UV) radiation and low photosynthetic photon flux density (PPFD). To characterize the optimal UV-B radiation dose and PPFD for enhancing the synthesis of phenolic compounds in basil plants without yield reduction, green and purple basil plants grown at two PPFDs, 160 and 224 μmol·m−2·s−1, were treated with five UV-B radiation doses including control, 1 h·d−1 for 2 days, 2 h·d−1 for 2 days, 1 h·d−1 for 5 days, and 2 h·d−1 for 5 days. Supplemental UV-B radiation suppressed plant growth and resulted in reduced plant yield, while high PPFD increased plant yield. Shoot fresh weight in green and purple basil plants was 12%–51% and 6%–44% lower, respectively, after UV-B treatments compared to control. Concentrations of anthocyanin, phenolics, and flavonoids in green basil leaves increased under all UV-B treatments by 9%–18%, 28%–126%, and 80%–169%, respectively, and the increase was greater under low PPFD compared to high PPFD. In purple basil plants, concentrations of phenolics and flavonoids increased after 2 h·d−1 UV-B treatments. Among all treatments, 1 h·d−1 for 2 days UV-B radiation under PPFD of 224 μmol·m−2·s−1 was the optimal condition for green basil production under a controlled environment.
Haijie Dou; Genhua Niu; Mengmeng Gu. Pre-Harvest UV-B Radiation and Photosynthetic Photon Flux Density Interactively Affect Plant Photosynthesis, Growth, and Secondary Metabolites Accumulation in Basil (Ocimum Basilicum) Plants. Agronomy 2019, 9, 434 .
AMA StyleHaijie Dou, Genhua Niu, Mengmeng Gu. Pre-Harvest UV-B Radiation and Photosynthetic Photon Flux Density Interactively Affect Plant Photosynthesis, Growth, and Secondary Metabolites Accumulation in Basil (Ocimum Basilicum) Plants. Agronomy. 2019; 9 (8):434.
Chicago/Turabian StyleHaijie Dou; Genhua Niu; Mengmeng Gu. 2019. "Pre-Harvest UV-B Radiation and Photosynthetic Photon Flux Density Interactively Affect Plant Photosynthesis, Growth, and Secondary Metabolites Accumulation in Basil (Ocimum Basilicum) Plants." Agronomy 9, no. 8: 434.
In recent years, consumption of herb products has increased in daily diets, contributing to the prevention of cardiovascular diseases, chronic diseases, and certain types of cancer owing to high concentrations of phytonutrients such as essential oils and phenolic compounds. To meet the increasing demand for high quality herbs, controlled environment agriculture is an alternative and a supplement to field production. Light is one of the most important environmental factors influencing herb quality including phytonutrient content, in addition to effects on growth and development. The recent development and adoption of light-emitting diodes provides opportunities for targeted regulation of growth and phytonutrient accumulation by herbs to optimize productivity and quality under controlled environments. For most herb species, red light supplemented with blue light significantly increased plant yield. However, plant yield decreased when the blue light proportion (BP) reached a threshold, which varied among species. Research has also shown that red, blue, and ultraviolet (UV) light enhanced the concentration of essential oils and phenolic compounds in various herbs and improved antioxidant capacities of herbs compared with white light or sunlight, yet these improvement effects varied among species, compounds, and light treatments. In addition to red and blue light, other light spectra within the photosynthetically active region—such as cyan, green, yellow, orange, and far-red light—are absorbed by photosynthetic pigments and utilized in leaves. However, only a few selected ranges of light spectra have been investigated, and the effects of light quality (spectrum distribution of light sources) on herb production are not fully understood. This paper reviews how light quality affected the growth and phytonutrient accumulation of both culinary and medicinal herbs under controlled environments, and discusses future research opportunities to produce high quantity and quality herbs.
Haijie Dou; Genhua Niu; Mengmeng Gu; Joseph G. Masabni. Effects of Light Quality on Growth and Phytonutrient Accumulation of Herbs under Controlled Environments. Horticulturae 2017, 3, 36 .
AMA StyleHaijie Dou, Genhua Niu, Mengmeng Gu, Joseph G. Masabni. Effects of Light Quality on Growth and Phytonutrient Accumulation of Herbs under Controlled Environments. Horticulturae. 2017; 3 (2):36.
Chicago/Turabian StyleHaijie Dou; Genhua Niu; Mengmeng Gu; Joseph G. Masabni. 2017. "Effects of Light Quality on Growth and Phytonutrient Accumulation of Herbs under Controlled Environments." Horticulturae 3, no. 2: 36.