( Syngenta Crop Protection, 2002 ). Moth orchids, which are the most common potted flowering orchids sold in the United States ( Griesbach, 2002 ), develop inflorescences from buds on the leaf nodes of their compressed stems. Some clones have very tall
Linsey A. Newton and Erik S. Runkle
Yin-Tung Wang and Elise A. Konow
2 Former graduate research assistant. We extend our appreciation to Taiwan Sugar Corporation, Taipei, Taiwan, the Republic of China for providing the orchid plants.
An experiment was initiated to determine the effect of a low N, high P and K fertilizer applied during the flowering season on a hybrid moth orchid (Phalaenopsis TAM Butterfly Blume.). On 1 Sept., plants of flowering size receiving N, P, and K at 100, 44, and 83 mg·L–1, respectively, from a 20N–8.8P–16.6K soluble fertilizer were given N, P, and K, at 30, 398, and 506 mg·L–1 (high P), respectively, at each or every fourth irrigation. Control plants continued to receive the 20N–8.8P–16.6K fertilizer. The high P treatments, regardless of the frequency of application, had no effect on the date of emergence of the flowering stem (spiking), anthesis, or flower size. All plants treated with the high P fertilizer had fewer flowers (15 to 19) than the controls (24 flowers). Continuous application of adequate N appears to be more important than low N and increased P for optimal flowering. In a separate experiment using the same hybrid orchid, terminating fertilization completely on 1 Sept., 29 Sept., or 27 Oct. or when the flowering stems were emerging (1 Oct.) reduced flower count (≤19 vs. 24). Flower longevity was reduced by 12 d when fertilization was terminated on 1 Sept. Flower size was unaffected by any treatment in either experiment. Discontinuing fertilization prior to late November reduced flower count. Withholding fertilization for extended periods resulted in red leaves, loss of the lower leaves, and limited production of new leaves.
Yin-Tung Wang and Elise A. Konow
Vegetatively propagated Phalaenopsis Atien Kaala `TSC 22' plants 10 cm in leaf spread were potted in a medium that consisted of either 100% fine grade Douglas fir bark or a mixture of 70% fir bark and 30% sphagnum peat. Plants were fertigated at each irrigation with 10N-13.1P-16.6K (10-30-20), 20N-2.2P-15.8K (20-5-19), 20N-8.6P-16.6K (20-20-20), or a 2N-0.4P-1.7K (2-1-2) liquid fertilizer at a common N rate of 200 mg•L-1. After 1 year in a greenhouse, plants grown in the bark/peat medium produced more leaves and had heavier fresh weights and larger total leaf areas than those in 100% bark. In the bark medium, the 20N-2.2P-15.8K fertilizer resulted in best plants, despite its low P concentration (22 mg•L-1). When grown in bark/peat, the two fertilizers (20N-2.2P-15.8K and 20N-8.6P-16.6K) containing urea as part of their N source (10% and 52%, respectively) resulted in plants with 40% to 50% heavier shoot fresh weight and 40% larger leaf area than the other fertilizers. With any given fertilizer, plants had similar root weights in both media. Media and fertilizers had limited or no effect on the concentrations of minerals in the second mature acropital leaves except P, the concentration of which nearly doubled in leaves of plants grown in 100% bark. Water extracts from the bark/peat medium had lower pH, higher EC, and elevated levels of NH4-N, Ca, Fe, Na, Cl, B, and Al than those from 100% bark. Exacts from the bark medium did not have detectable levels of NO3-N, whereas extracts from the bark/peat medium all had similar levels of NO3-N, regardless of which fertilizer was applied.
Marco A. Palma, Yu-Jen Chen, Charles Hall, David Bessler, and David Leatham
potted orchid species. Moth orchid ( Phalaenopsis spp.) dominates the U.S. orchid market, and accounts for more than 80% of all orchid production value ( Griesbach, 2002 ; Runkle et al., 2005 ). The location of Hawaii provides ideal conditions and the
1 Professor. This research was support in part by a grant from the American Orchid Society and by private donations. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper
Kaylee A. South, Paul A. Thomas, Marc W. van Iersel, Cindy Young, and Michelle L. Jones
of orchids that are sold each year is increasing. Most commercial orchid sales are Phalaenopsis sp ., also called moth orchids ( Griesbach, 2002 ). The USDA Floriculture Crops Summary reported the wholesale value of potted orchids (including
Elise A. Konow and Yin-Tung Wang
Presently, there are no standards for producing Phalaenopsis Blume (the moth orchids) as a flowering, potted crop. Determining optimal irradiance for in vitro and greenhouse production will help optimize growth and flowering. Four-month-old, aseptically propagated Phalaenopsis Atien Kaala seedlings with 1.0 cm leaf spread were transferred to a sterile agar medium in November 1995. They were placed under 10, 20, 40, or 80 μmol·m-2·s-1 photosynthetic photon flux (PPF) from cool-white fluorescent lamps. In June 1996, plants grown under 40 or 80 μmol·m-2·s-1 in vitro PPF had 38% greater fresh weight (FW), wider leaves, and more roots than those under the two lower PPF levels. Plants from each in vitro PPF were then transplanted and grown ex vitro in a greenhouse (GH) under high, medium, or low PPF, representing 12.0%, 5.4%, or 2.6% of full sunlight, respectively. Full sunlight at this location was 2300 and 1700 μmol·m-2·s-1 in August 1996 and January 1997, respectively. In November 1996 and June 1997, plants that had received 40 μmol·m-2·s-1 in vitro PPF and then grown under the high or medium GH PPF had the greatest FWs. Overall, plants under the high, medium, or low GH PPF had average FWs of 61, 36, or 17 g, respectively, in June 1997. By mid-September 1997, plants had increasingly larger leaves and higher concentrations of malic acid, sucrose, and starch as GH PPF increased. Leaf glucose and fructose concentrations remained constant as GH PPF increased; however, sucrose level doubled and malic acid concentration increased by nearly 50% from the low to high GH PPF. Each doubling in GH PPF more than doubled plant FW. Plants grown under the high, medium, or low GH PPF had 98%, 77%, or 2% flowering, respectively, in Spring 1998. Anthesis occurred 2 weeks earlier under the high GH PPF. Plants grown under the high GH PPF had twice as many flowers and larger flowers than those grown under the medium PPF.
Matthew G. Blanchard and Erik S. Runkle
Nash, N. 2003 Phalaenopsis primer: A beginner's guide to growing moth orchids Orchids 72 906 913 Pridgeon, A. 2000 The illustrated encyclopedia of orchids Timber Press Portland, OR
Dansereau Blanche and Charest Pierre-Mathieu
biology of the principal Invertebrate pollinators and some Vertebrate pollinators. The taxonomic presentation enables the reader to seek specific information on bees, flies, or moths and so on. Emphasis is placed on the phylogenetic, ecological, and