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  • Author or Editor: George E. Rottinghaus x
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Black cohosh [Actaea racemosa L.; Cimicifuga racemosa (L.) Nutt.] is a perennial herb native to North America that is commonly used for the treatment of menopausal symptoms. The plant is almost exclusively harvested from the wild and is being threatened by overharvesting in some regions. As demand for this plant continues to increase, the potential for profitable cultivation of this species is becoming realistic. Little is known about the effect of various cultivation practices, soils, environments, and harvest times on the multitude of phytochemicals that occur in black cohosh. Furthermore, although the rhizome is the organ that is traditionally consumed, other tissues also contain various quantities of important phytochemicals, but this has not been well documented. The objectives of this study, therefore, were to ascertain any environmental effects on the production of two representative phytochemicals (23-epi-26-deoxyactein and cimiracemoside A) and to elucidate any season-long patterns or variations in the production of these compounds within five black cohosh tissues (leaf, rachis, rhizome, root, and inflorescence). All black cohosh tissues contained 23-epi-26-deoxyactein with substantially more, as a percentage of dry weight, detected in inflorescence (28,582 to 41,354 mg·kg−1) and leaf (8250 to 16,799 mg·kg−1) compared with rhizome (2688 to 4094 mg·kg−1), and all tissues experienced a linear season-long decrease in occurrence of this compound. Cimiracemoside A was not detected in leaf tissues. The highest levels were found in rhizome (677 to 1138 mg·kg−1) and root (598 to 1281 mg·kg−1), which likewise experienced a significant season-long decrease in this compound, whereas levels in the rachis (0 to 462 mg·kg−1) increased over time. In general, environmental factors did not affect production of either compound. Varying seasonal patterns in phytochemical production, combined with differences in phytochemical content among plant tissues, point to the potential for more targeted horticultural production of these and other medicinal compounds within black cohosh.

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A long-term horticultural experiment was conducted at two geographically distinct sites in southern Missouri in 2011–15 to study the response of American elderberry [Sambucus nigra (L.) subsp. canadensis (L.) Bolli] to various soil nitrogen (N) fertilizer levels. Three commercially available elderberry cultivars (‘Adams II’, ‘Bob Gordon’, and ‘Wyldewood’) were used. The three cultivars were each assigned to 16 of 48 four-plant plots in a completely randomized manner at each site. Four replications of four N fertilizer treatments (0, 56, 112, 169 kg⋅ha−1 N) were randomly assigned to each cultivar’s plots and applied for 4 years (2012–15). Fruit yields, plant growth, phenology, and pest incidence were determined each year. Fruit quality was assessed by analyzing basic juice characteristics as well as organic acids, carbohydrates, anthocyanins, and polyphenols from 2012–14 samples. Leaf tissue analysis determined the plants’ mineral contents in 2012–14. Most factors evaluated were significantly affected by site, year, and cultivar, whereas the effects of N fertilizer treatment were less definitive. Fruit yields and plant growth increased with increasing N levels. For example, plants fertilized with 0, 56, 112, and 169 kg⋅ha−1 N produced 123, 137, 155, and 161 fruiting cymes per plot (5.8 m2), respectively. The eriophyid mite incidence was higher on fertilized plants, but other pests were not influenced by the N treatment. Basic fruit juice characteristics (soluble solids, pH, titratable acidity, polyphenols) were not influenced by the N treatment, whereas total anthocyanins were statistically higher in unfertilized plants. Levels of organic acids and carbohydrates in juice varied statistically among N treatments, but patterns were difficult to discern. Leaf N concentrations were correlated with N fertilizer levels—2.75% N with the highest fertilizer level compared with 2.55% N in unfertilized plants. Leaf levels of most other macronutrients varied, but consistent patterns did not emerge, and none of the micronutrients was different among N treatments. Although elderberry plants responded positively to increased N fertilizer levels in terms of plant growth and fruit yield, genetics (cultivar) and environment (site, year) were more influential on most other experimental factors evaluated.

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