Growth and fruiting pattern of okra (Abelmoschus esculentus L. Moench) cv. Clemson Spineless as affected by the growth regulators Alar (N -dimethylaminosuccinamic acid) and ethephon (2-chloroethyl phosphoric acid) were evaluated in field studies. Eight treatments consisting of Alar at 600, 1200, 2400, and 3600 μl·liter-1 and ethephon at 200, 400, 600, and 800 μl·liter-1 and water control were applied as foliar sprays at the three- to four-true-leaf stage. Both growth regulators depressed shoot growth and leaf production. Ethephon reduced shoot length. Total fruit yield was not significantly affected by the treatments. However, ethephon-treated plants tended to produce fewer fruits and lagged behind Alar-treated plants and the control plants in Fruit production during the early harvests.
Lurline Marsh, Rufus Jones and Mark Ellersieck
Andrew L. Thomas, Patrick L. Byers and Mark R. Ellersieck
American elderberry [Sambucus canadensis L.; Sambucus nigra ssp. canadensis (L.) Bolli] is being increasingly cultivated in North America for its edible fruit and flowers, yet it remains largely undeveloped as a horticultural crop. Elderberry is a shrub that produces fruit on both new and old wood, thereby offering unique pruning management opportunities and challenges. The objective of this study was to document the response of American elderberry to various pruning methods in terms of flowering, fruit yield, phenology, plant growth, and incidence of disease and arthropod pests and to consider the impact of various pruning methods on horticultural management. Four pruning treatments (annual removal of all shoots, biannual removal of all shoots, annual selective pruning, and no pruning) were studied among three cultivars at two Missouri sites over 5 years. Although significant interactions among experimental effects made interpretation challenging, several trends were evident. Annual selective pruning was an excellent way to manage elderberries with mean yields of 1086 g/plant across all experimental parameters; however, pruning to the ground annually or biannually also resulted in satisfactory yields (855 and 1085 g/plant, respectively) with a fraction of pruning labor involved. Pruning plants to the ground consistently resulted in fewer, but larger, fruiting cymes compared with selectively pruned or unpruned plants, which may be important in terms of harvest efficiency. Pruning treatment generally affected the time of flowering and fruit ripening; plants that flowered only on new stems (after removal of all shoots) ripened fruit 14 to 21 days later than plants that fruited on old wood. Although annually pruned plants generally yielded lower, the plants remained vigorous and productive, and this pruning management technique may have numerous advantages over other pruning methods.
Andrew L. Thomas, Richard J. Crawford Jr, George E. Rottinghaus, John K. Tracy, Wendy L. Applequist, Besa E. Schweitzer, Larry J. Havermann, Scott F. Woodbury, James S. Miller, Mark R. Ellersieck and Dean E. Gray
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.