Hawaii Cooperative Extension Service

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1 Hawaii Cooperative Extension Service HO'RTICULTU'RE HITAHR College of Tropical Agriculture and Human Resource. U. S. Department of Agriculture Cooperating 'DIGEST Department of Horticulture University of Haw.1I at Manoa In This Issue: FLOWER AND NURSERY INFORMATION No. 76, May 1985 TABLE CONTENTS Page Evaluation of Dendrobium Selections Under Test with Cooperators... 1 Coming Events Dendrobium Lynne Horiuchi-A Seed Propagated, Flowering Potted Plant Cultivar... 3 Available Publications... " 4 Dendrobium Mini Pearl 'Elaine Fuchigami' and Dendrobium Royal Satin 'Alii'... 5 EV ALVA TION OF DENDROBIUM SELECTIONS UNDER TESTS WITH COOPERATORS The first mericloned dendrobium selection, K230-l5, was distributed to cooperators for advance testing in February, Since then mericlones of the following selections were distributed to cooperators: K and K228-2l in August, 1 982;K364-4 in January, 1983;K3l8-ll and K in March, 1983; and K251-35, K350-3 and K in August, All of the above selections were also grown concurrently in the saranhouse and a few selections in the greenhouse at the Mauka Manoa Campus of the University of Hawaii. Sufficient testing time has elapsed to draw some conclusions on their performances. Following are the cooperators who participated in the tests: Mordecai Hudson-Hawaii Orchid Nursery, Waianae Francis Nitta-Nitta's Nursery, Waimanalo Walter Oumae-Walter Oumae Orchids, Waialae Wayne Tsue-Gordan's Nursery, Pupukea Helen Wong-Mahalo Farms, Waimanalo Warren Yee-The Plant Place, Waimanalo Selections were made on their potentials as either cut flowers (including individual flowers for leis) or flowering potted plants. Most of the selections for flowering potted plants were smallflowered hybrids involving Dendrobium canaliculatum as one parent. Table 1 gives some of the characteristics of the initial plant selection grown in the greenhouse at the Mauka Campus. 'K K230-l5 is a selection from the cross between D. Salak and D. canaliculatum, which was registered as D. Spiral Gem. A tetraploid form of D. Salak (D. stratiotes x D. undulatum) was used, and therefore K is a triploid. Flowers of the selection are small but attractive with yellow spiraled sepals and petals and purple lip. Keeping quality is good. It flowers throughout most of the year. In the early stages of testing when the plants were still young and short, some cooperators were impressed with the performance and requested our "early release" of plant material for further micro-propagation by the dendrobium growers organization. This request was approved. However, as the plants matured, they attained an excessive height in several locations. On the other hand, with relatively high light intensity and/or reduced fertilization, acceptable plant height has been maintained in two locations. One of the cooperators felt that despite the small flowers, the good vase life of sprays and high yields might warrant its cultivation. K This selection is a free-flowering, smallflowered, compact plant intended as a flowering potted plant. It is a cross between D. antennatum (D. d'albertissii) and D. canaliculatum which has the registered name, D.LowanaNioka. The original selection grown in 8-inch pots in the Mauka Campus greenhouse produced 97 sprays in 1979, 158 sprays in 1980 and 150 sprays during the first half of COOPERATIVE EXTENSION SERVICE 3050 MAILE WAY' UNIVERSITY OF HAWAII. HONOLULU, HAWAII The University of Hawaii at Manoa, College of Tropical Agriculture and Human Resources, Cooperative Extension Service and U.S. Department of Agriculture cooperating in presenting to the people of Hawaii programs and services to its citizens without regard to race, color, national origin, or sex. It is an equal opportunity employer.

2 Soon after distributing mericlones of this selection to cooperators in August, 1982, plants appeared promising, and therefore like 'Spiral Gem', cooperators sought an "early release", which was approved. The attributes of this selection are floriferousness, especially during winter and spring, the dainty flowers, and short and compact growth. A serious weakness appears to be its susceptibility to diseases. Several of our plants in the saranhouse died from Phytophthora. Also leaf diseases caused unsightly necrotic leaf spots and excessive leaf drop. However, plants grown in the greenhouse were free of foliar diseases, retained their leaves and produced numerous flower sprays. Thus, 'Lowana Nioka' may be an acceptable cultivar as a flowering potted plant under greenhouse conditions, but probably not under saran, unless foliar diseases can be controlled. K This is another small-flowered selection intended as a flowering potted plant. The cross between D. tokai and D. canaliculatum was registered as D. Tocanal. Grown in the greenhouse in a 6-inch pot, K produced 29 sprays in 1979, 54 sprays in 1980 and 69 sprays in 1981, mostly during the spring. Mericlones performed poorly in all locations. Consequently this selection is being dropped from the test. K364-4 Triploid Spiral Gem, (K230-15) was backcrossed to diploid D. canaliculatum to produce tetraploid D. Plum Jade (K364). Flowers are similar to 'Spiral Gem', but stems are much shorter attaining a height of only 20 inches. Flowering is heavy during spring. Like K mericlones have not performed well at all locations including the saranhouse at the Univeristy of Hawaii. However plants grown concurrently in the greenhouse are doing well. Probably this selection, like the D. canaliculatum parent, cannot tolerate excessive moisture. K This is the first of the large-flowered hybrids selected for testing as a flowering potted plant. The cross between D. Field King and D. Sandy Kunimoto was registered as D. Evelyn Nakasato. Flowers are large and full, measuring 3~ x 212 inches. The attractive flowers have contrasting colors: sepals are light purple, petals are purple 2 and the lip is dark purple. The back of sepals are light yellow-green when flowers are young. The pseudobulbs are short and sturdy. Most of the cooperators have expressed satisfaction with this selection. Even with a single spray per pseudobulb, the flowering plant may be saleable because of its large flowers and attractive contrasting colors. Another attribute is its short stature. Plants grown in the University greenhouse were free of fungal leaf spots and superior to those grown in the saranhouse. K K318 is a cross between D. Jaquelyn Thomas 'Nat Seefurth' and D. Sandy Kunimoto. This offspring is the PPPC type with three sets of the P (D. phalaenopsis) genome and one set of the C (D. gouldii) genome and is somewhat comparable to the genome make-up of D. Pompadour. K was selected for cut flower purposes. It gave about 10 sprays per year with relatively good keeping quality for a PPPC hybrid. Cooperators expressed mixed reaction from mediocre to good performance. However, since propagation of this selection is dependent on tissue culture, its merit for cut flower production is questioned. K350 3 and K Both of these selections are similar to white D. Walter Oumae and has a triploid D. Walter Oumae in their pedigree. They were selected for their attractive upright sprays, good yield and seasonality and long vase life. Both selections produce flowers with cymbidium mosaic virus induced necrosis in old flowers. Consequently both selections are being dropped from the test. K As a first step toward producing a good yellow cut flower cultivar, we crossed a white tetraploid D. Jaquelyn Thomas with a tetraploid yellow-bronze D. Field King. The offspring was predominantly light lavender. By crossing a selected offspring to tetraploid D. May Neal 'Srisophon', several promising yellows were obtained, one of which was selection K Petals and sepals of this selection are yellow-green and the lip is purple. Plants under test are vigorous and just began flowering. Further observation and evaluation is required to draw any conclusions on this selection.

3 H. Kamemoto, Professor James Kam, Graduate Student Department of Horticulture University of Hawaii COMING EVENTS Dendrobium Conference The 1985 Dendrobium Conference has been scheduled for October at the Naniloa Surf Hotel in Hilo. Contact Dwight Sato at the Hilo Extension office for further information, (875 Komohana St., Hilo, HI 96720) Nursery Conference The Annual Hawaii Association of Nurserymen Conference and Trade Show will be held at the Ala Moana Americana Hotel in Honolulu on October 21-24, Trade show booth for the 25 th anniversary is nearly sold out. CAN will be holding their annual conference on Maui the following week and it is anticipated that many of the California nurserymen will also attend the HAN conference. Ornamental Short Course The dates of January 9-11, 1986 have been set for the Annual Ornamentals Short Course to be held at the Naniloa Surf Hotel in Hilo. As in the past, this program will be held in conjunction with the Annual Fertilizer Conference. Tentative plans are to hold the educational sessions on Thursday and Friday, January 9-10, and have the industry tour on Saturday. DENDROBIUM LYNNE HORIUCHI-A SEED PROPAGATED,FLOWERINGPOTTED PLANT CULTIV AR The University of Hawaii has released to date five seed-propagated, amphidiploid, dendrobium cut flower cultivars: 'Uniwai Blush' (UH44), 'Uniwai Supreme' (UH232), 'Uniwai Pearl' (UH306), 'Uniwai Prince' (UH503), and 'Uniwai Princess' (UH507). The significant feature of these cultivars is their propagation from seeds. The advantages of seed-propagated dendrobium cuitivars over those clonally propagated through tissue culture are that they are easier, faster and cheaper to propagate, and the resulting seedlings are free of cymbidium mosaic virus since the virus is not transmitted from seeds. In light of the success in developing the above seed-propagated cut flower cultivars, we have recently directed our attention to developing 3 seed-propagated flowering potted plant cultivars. Dendrobium Lynne Horiuchi (UH613) is the first seed-propagated dendrobium flowering potted plant cultivar introduced by the University of Hawaii. Dendrobium Lynne Horiuchi is a triploid progeny from a cross between amphidiploid D. Macrobig (D. macrophyllum x D. bigibbum) and diploid D. bigibbum. The initial cross was made in November, 1978 and repeated in April, The purple-violet flowers are round and full like D. phalaenopsis, but relatively small, measuring about 2 inches across. The petals and sepals are edged with white, and the lip has a white spot in the throat. The plants are relatively short. The characteristics of D. Lynne Horiuchi are as follows: Scape length (in.) 5.1 ± 1.2 Raceme (spray) length (in.) 11.8± 2.8 No. of flowers per raceme l5.6± 2.9 Percent bud drop 1.3 Natural spread of flowers (in.) 1.6± 0.1 Pedicel length (in.) 0.6± 0.1 Leaf length (in.) 6.2± 1.6 Leaf width (in.) O.8± 0.3 Half-life of racemes on plants (days) 33.4± 10.8 Plant height (in.)-january, ± 3.1 Plant height (in.)-december, ± 4.7 The leaves of 'Lynne Horiuchi' are thin and pliable which should facilitate packing and shipping plants. The half-life of sprays, as determined from the time 3/4 of the flowers on the raceme open until Y2 of the flowers wither or drop, averaged 33 days. However when half-life was calculated from the time the first flower on the spray opened until half of the flowers withered or dropped, the duration was 52 days or close to two months. Table 1 shows monthly and annual raceme yield of 'Lynne Horiuchi', and the number of plants considered saleable during the month. A minimum of two racemes on the plant in any given month was considered potentially saleable. Peak flowering and the corresponding high saleability of plants occurred between January and April. The height of the plants by the end of December, 1984 was 24 inches which might be undesirably tall. The majority of plants, however, were in saleable condition during early 1983 when plants averaged only 14.2 inches. The cross was repeated on October 25,1981. to determine if the performance can be more or

4 Table 1. Monthly and annual raceme yield and number of saleable plants per month of 'Lynne Horiuchi' (K613) based on 40 plants. Month No. racemes No. saleable* No. racemes No. saleable* plants plants Jan Feb Mar Apr May C'.J June July Aug Sept 7 I 37 9 Oct Nov Dec II TOTAL * Saleable plants are those with at least two racemes (sprays) per plant. The total number of saleable plants exceeds 40 because many plants were saleable during several months. Table 2. Monthly raceme (spray) yield and saleability of 'Lynne Horiuchi' (K807) based on 32 plants. Month No. of racemes No. of saleable plants* Aug 84 4 Sept Oct Nov Dec Jan Feb Mar TOTAL * Saleable plants are those with at least two racemes (sprays) per plant in any month. The total num ber of saleable plants exceeds 32 because some plants were saleable during more than one month. 4 Figure 1. Dendrobium Lynne Horiuchi in 5-inch pots. less repeated. Seeds were germinated on March 6, 1982, and seedlings were transflasked on May 18, 1982, compotted on October 9, 1982, transplanted into 2-inch pots on April 7, 1983, and transplanted' into 5-inch pots on October 28, Plants began to flower in fall, only 2Y2 years after germination. By March, 1985,3 years after germination, most of the plants were saleable as flowering plants (Table 2). The height of the plants averaged only 13.8 inches, and the height including the racemes (sprays) was 24.4 inches (Fig. 1). Thus, if flowering plants can be sold within the first year of flowering, 'Lynne Horiuchi' may prove to be an excellent dendrobium flowering potted plant cultivar. H. Kamemoto, Professor James Kam, Graduate Student Department of Horticulture University of Hawaii AVAILABLE PUBLICATIONS A number of new publications have recently been published by the College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa related to ornamental horticulture. Single copies are available from your County Extension office or by contacting the Agricultural Publications and Information Office, 2500 Dole Street, Krauss Hall, Room 6, Honolulu, Hawaii

5 Dendrobium Virus Research on the Incidence and Expression of Cymbidium Mosaic Virus in Dendrobium Hyrids is reported in Res. Series 033 by A. K. Okemura, H. Kamemoto, and M. Ishii. There was a linear increase in infected plants with the time of approximately 15 percent per year for plants 4 to 7 years of age. They suggest that flower yield may be depressed in CyMV -infected plants and that genetic variability for resistance to CyMV-induced flower necrosis exists in Dendrobium. Dendrobium Weed Control Experiments on Chemical Weed Control in Dendrobium Orchid is reported in Research Series 037 by T. Higaki, J. S. Imamura, and R. K. Nishimoto. Under the conditions of the test, Oxadiazon at 4.0 lb/a, diuron at 2.0lb/A, and simazine at 2.0 lb/a gave the best weed control with no apparent detrimental effects on the dendrobium plants, flower yield, flower spray length, number of flowers per spray or bud drop. Nutrition of Anthurium Studies to determine the Nutrient Deficiency in Anthurium are reported in Research Extension Series 047 by J. S. Imamura and T. Higaki. A description of the various nutrient deficiency symptoms is provided along with color plates of. each symptom induced. Ground Covers Ground Covers for Warm Climates by F. D. Rauch (Research Extension Series 052) provides an annotated check list of the wide variety of plant material that may be useful as a ground cover under tropical conditions. Flowering Potted Plants The Flowering Potted Plant Workshop Proceeding by F. D. Rauch and K. W. Leonhardt (Research Extension Series 054) is now available. This publication includes papers on chrysanthemum, poinsettia, lily, azalea and miscellaneous plants as well as a review of what's new abou t using growth regulators on floriculture crops. DENDROBIUM MINI PEARL 'ELAINE FUCHIGAMI' AND DENDROBIUM ROY AL SATIN 'ALII' In March, 1978, we remade the cross registered as Dendrobium Mini Pearl by Ralph Yagi 5 in 1974, using as parents D. bigibbum var. compactum (K388-24) and D. canaliculatum (D173-2). In November, 1980,'one seedling of this cross was selected, labelled as K580-3, transplanted into a 5-inch clay pot, and put in the greenhouse at the Mauka Manoa Campus for evaluation as a flowering potted plant cultivar. K580-3 produced 14 sprays in February, 1982 and an additional 14 sprays in April, 1982 (Fig. 1). The sprays on the plant remained attractive for a month in the air-conditioned, artificially-lighted Department of Horticulture office. We named this clone 'Elaine Fuchigami' in honor of the wife of the then Chairman of the Horticulture Department, and proceeded to mericlone it for ultimate release to growers as a potted plant cultivar. The first plantlets derived from meristem culture were transflasked in May, 1983, compotted in October, 1983, and transplanted into 2-inch pots in February, Some mericlones began to flower as early as December, 1984, while others flowered between January to April, The pseudobulbs of flowering plants in the 2-inch pots ~veraged only 3.5 inches (Fig. 2). Although mericlones in 2-inch pots performed well, they performed poorly in the saranhouse, probably due to the excessive rainfall during the winter of It seems that, like both parental species, D. bigibbum andd. canaliculatum, D. Mini Pearl cannot tolerate excessive moisture. However, if excess moisture can be avoided, 'Elaine Fuchigami' should make an excellent mini-flowered potted dendrobium. Thirty-two plants in 2-inch clay pots can be grown and flowered in a 8 x 16 inch compartmented plastic tray. Some characteristics of 'Elaine Fuchigami' are shown in Table 1. A second seedling (K2l7-21) was selected from a cross between D. Memoria Edward Trevor and D. Sandy Kunimoto. This cross was made in January, 1971, flowered in September, 1974, and was registered as D. Royal Satin. This selection has attractive, velvety, red-purple flowers, wide seasonality, medium-sized flowers measuring about 2Y2 inches across, and relatively short stature. Some characteristics of K2l7-2l, which was named 'Alii' (Fig. 3), are presented in Table 1. Plantlets obtained through meristem culture were compotted in November, 1983 and transplanted into 2-inch pots in August, Several plants in 2-inch pots flowered in March, 1985 (Fig. 4). Pseudobulbs averaged 4 inches and the total height (pseudobulbs and flower

6 Figure 1. 'Elaine Fuchigami' in 5-inch pot in April, 1982 with 14 sprays. Figure 2. 'Elaine Fuchigami' in 2-inch pot in March,

7 Figure 3. D. Royal Satin 'Alii'. Figure 4. 'Alii' in 2-inch pot, March,

8 Table 1. Some characteristics of D. Mini Pearl 'Elaine Fuchigami' and D. Royal Satin 'Alii'. CHARACTERISTICS ELAINE FUCmGAMI ALII Flower color Purple-violet RHSCC 8lA Red-purple RHSCC 7lA Size of flower (in.) Pedicel Length (in.) Scape length (in.) Spray length (in.) Flowers per spray Height of pseudo bulb sprays) averaged only 10 inches. However, as the meric10ned plants mature, the pseudobulbs are expected to be taller, but probably will not exceed 18 inches. A limited number of plants of D. Royal Satin 'Alii' and D. Mini Pearl 'Elaine Fuchigami' have been released for trial to the dendrobium industry of Hawaii for production as flowering potted plants. H. Kamemoto, Professor Ruth S. Kobayashi, Research Assistant Department of Horticulture University of Hawaii NOTE: The use of trade names is for the convenience of.readers only and does not constitute an endorsement of these products by the University of Hawaii, the College of Tropical Agriculture and Human Resources, the Hawaii Cooperative Extension Service, and their employees. Fred D. Rauch Extension Specialist in Horticulture 8