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Abstract

Single and multiple applications of 2,4-D to American ginseng (Panax quinquefolium L.) with fully expanded leaves during a 3-year period caused no visible injury to foliage or roots. During the final 2 years of the study, percent plant survival was greater with two applications per year than with one, and percent gain in root weight decreased with increased rate of application of the herbicide. Also, terminal weight of roots decreased with increased number of years of herbicide application. Treated plants did not differ from nontreated plants in percent survival, final root weight, or percent gain in root weight. Herbicide residue was not detected (<0.02 ppm) in roots from plants that received multiple applications of the three highest 2,4-D dosages: 0.56, 1.12, or 2.24 kg·ha−1 a.i. Foliar residues were detected in plants treated once or twice per year for 3 years with 0.56 or 1.12 kg·ha−1 a.i. 2,4-D. Chemical name used: (2,4-dichlorophenoxy)acetic acid (2,4-D).

Open Access

In the Northeast, wild American ginseng (Panax quinquefolium L.) is typically found growing in the dense shade provided by deciduous hardwood tree species such as a sugar maple, in slightly acidic soils with relatively high calcium content. Woods cultivated ginseng is often grown in forest farming agroforestry systems under similar conditions. Supplemental calcium by soil incorporation of gypsum (CaSO4·2H2O) is often recommended for woods cultivated ginseng. The objective of this study was to investigate the effects of this practice on soil chemical properties, plant growth and quality of American ginseng. In a greenhouse pot culture experiment, 2-year-old seedlings were treated with 0, 2, 4, 8, or 16 Mt·ha–1 gypsum and grown for 12 weeks. Gypsum application decreased soil pH slightly, elevated soil electrical conductivity and increased available soil Ca and sulfate concentrations. Tissue calcium concentration was increased with by gypsum treatment, but shoot and root growth was reduced. HPLC analysis of root ginsenosides revealed that Re, Rb1, Rc, and Rb2, PT ginsenoside (sum of ginsenoside Rb1, Rc, Rb2, and Rd) and total ginsenoside concentration increased by gypsum soil amendment.

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Woods cultivation of North American ginseng (Panax quinquefolium L.) can generate income for forest land owners and decrease collection pressure on wild populations of this increasingly scarce forest herb. For woods cultivation, supplemental calcium by soil application of gypsum (CaSO4 2H2 O) is often recommended, but the effects of this practice on soil characteristics, plant growth and quality of American ginseng are not well characterized. In a greenhouse pot culture experiment, 3-year-old seedlings were treated with 0, 1, 2, 3, or 4 Mt/ha gypsum and grown for 12 weeks. Gypsum application decreased soil pH slightly and elevated soil electrical conductivity and available soil calcium. Tissue levels of calcium were not affected by gypsum treatment but a significant increase in both shoot and root dry weight occurred. Total ginsenosides, which are the pharmacologically active components of ginseng, were increased slightly in roots but not in shoots of plants treated with 4 Mt/ha gypsum. Rb1, the most abundant ginsenoside in roots, was elevated in roots of plants treated with 3 Mt/ha gypsum. Ginsenoside Rg1 was elevated in shoots of plants treated with 2 Mt/ha gypsum. Regardless of gypsum treatment, qualitative differences (relative concentrations of different ginsenosides) between roots and shoots were observed.

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American ginseng (Panax quinquefolium L.) contains pharmacologically active secondary compounds known as ginsenosides, which have been shown to be affected by both genetic and environmental factors. In this greenhouse experiment, we tested the hypothesis that ginsenosides would behave as “stress metabolites” and be associated with osmoregulation in response to drought stress. Two year-old seedlings, grown in 5-inch pots, were well watered for 40 days prior to the initiation of treatments. Plants in the drought stress treatment were watered every 20 days while the controls were watered every 10 days, and the experiment was terminated after 4 and 8 dry down cycles (80 days), respectively. Predawn leaf water potential and relative water content (RWC) of drought-stressed plants during a typical dry down cycle were lower than control plants. The diameter and weight of primary storage roots were decreased in the stressed treatment. The length of the main storage root and the longest secondary (fibrous) root were significantly increased by the drought stress treatment. Leaf chlorophyll content of drought-stressed plants was lower than controls. The osmotic potential of the drought-stressed ginseng was not lower than the control, indicating that ginsenoside is not involved in osmoregulation in response to drought stress. Furthermore, ginsenosides Rb1 and Rd, and total ginsenosides were significantly lower in primary roots of drought-stressed plants compared to control plants.

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cultivation methods on ginsenoside content of wild American ginseng ( Panax quinquefolium ) J. Agr. Food Chem. 53 8498 8505 Mathur, A. Mathur, A.K. Sangwan, R.S. Gangwar, A. Uniyal, G.C. 2003 Differential morphogenetic response, ginsenoside metabolism and RADP

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.A. Reynolds, L.B. Hendel, J.G. 1996 Influence of root age on the concentration of ginsenosides of american ginseng ( Panax quinquefolium ) Can. J. Plant Sci. 76 853 855 10.4141/cjps96-144 Dong, T.T.X. Cui, X.M. Song, Z.H. Zhao, K.J. Ji, Z.N. Lo, C.K. Tsim, K

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011573d Du, X.W. Wills, R.B.K. Stuart, D.L. 2003 Changes in neutral and malonyl ginsenosides in American ginseng ( Panax quinquefolium ) during drying, storage and ethanolic extraction Food Chem. 86 155 159 Faridah, Q.Z. Abdelmageed, A.H.A. Nor, H

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) and ginseng ( Panax quinquefolium ) plants ( Hill and Hausbeck, 2005 ). Mefenoxam is recommended for control of PRR in North Carolina ( Sidebottom and Jones, 2004 ) and has been shown to have mixed effectiveness against P. cinnamomi ( Benson et al

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ginsenoside content of American ginseng ( Panax quinquefolium L.) Acta Hort. 629 161 166 Panossian, A. Danielyan, A. Mamikonyan, G. Wikman, G. 2004 Methods of phytochemical standardisation of rhizoma

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