times ( Purseglove et al., 1981 ), and is now cultivated and used worldwide. The rhizome contains the flavor and pungency of the culinary spice together with the essential volatile oils ( Zarate and Yeoman, 1994 ). Ginger leaves are also aromatic and
Goldenseal (Hydrastis canadensis) is an herbaceous perennial valued for its fleshy rhizomes, which contain the alkaloids hydrastine and berberine. While it is understood that relative shade influences growth and yield of goldenseal, optimal shade level for maximum rhizome mass and plant vigor under cultivation has not been established. Goldenseal plants grown from cold stratified rhizomes were kept under shade for 5 months in the greenhouse. Treatments were five different shade levels ranging from 60% to 95% of full shade, plus a control group in full sun. Measured variables included rootlet length, bud development, and rhizome mass. Plants grown under moderate shade (60 to 70%) produced longer and more numerous rootlets, more bud primordia, and had greater rhizome mass and healthier leaves than plants grown under extreme shade (95%) or in full sun. Decreasing shade density had a major impact on plant condition and growth. Those plants grown with the greatest sun exposure displayed 100% scorch damage to the foliage, in comparison to <35% damage in the moderate shade (30 to 40%). The results suggest that moderate shading may double yield in rhizome mass, and promote increased bud proliferation in subsequent seasons. Late season leaf vigor is not correlated with rhizome mass.
the subfamily Gesnerioideae and tribe Gesnerieae with plants that form mainly from scaly rhizomes ( Zimmer et al. 2002 ). Eucodonia is closely related to Achimenes , and species in both genera produce plants that have scaly rhizomes. When plants of
Lotus is an aquatic perennial vegetable native to many subtropical and temperate zones, and cultivated extensively throughout Asia ( Huang et al., 2003 ). Rhizomes, stems, flowers, seeds, and young leaves of lotus are in great demand and considered
Approved for publication by the director of the Louisiana Agricultural Experiment Station as manuscript no. 97-28-0398. The rhizomes for this research were provided by Golden State Bulb Growers, Watsonville, Calif. The cost of publishing this paper
Experiment Station, Univ. of Minnesota, St. Paul, MN 55108. We thank Brown Bulb Co., Capitola, Calif., and the New Zealand Calla Producers Assn. for donating the rhizomes used in this study. Portions of this research were funded by the American Floral
compared with epiphytic species and their hybrids ( Liu et al. 2017 ; Shimasaki and Uemoto 1991 ). Additionally, the routes for in vitro shoot formation are different between temperate and tropical Cymbidium species. Temperate species first form rhizomes
, 2013 ). Current nursery propagation of C. peregrina by rhizome division is not meeting consumer demand for this plant. C. peregrina is difficult to propagate from seed due to germination inhibitors present in the seedcoat ( Del Tredici and Torrey
commercial production. Tissue culture is a rapid and efficient way to propagate C. goeringii . During propagation of C. goeringii , mature seeds are often used as the material to obtain sterile rhizomes for further proliferation and differentiation. The
Ginger ( Zingiber officinale , Roscoe) is one of the world’s leading spice crops and is used for both its medicinal and flavor qualities. It grows well in tropical regions such as Southeast Asia, from which it originated. The rhizomes mature in 8