Progress 10/14/02 to 10/13/08
Outputs
Production parameters for potted orchid production have been developed, including media composition, fertility procedures, light levels, temperatures, etc. alone and in combination to optimize growth, development, flowering, and post-harvest effects. Temperature regimes have been determined to be a main factor in the initiation of floral shoots, and management manipulation can time production to meet peak demands, such as Easter. Similar studies have been conducted with other woody and tropical foliage plants to better understand physiology and optimize growth and production parameters. With the retirement of Dr. Y.T. Wang, this project has concluded.
Impacts
Research into the growth and development of potted orchids resulted in the widespread commercialization of Phalaenopsis in the U.S., especially in the areas of media, temperatures, light effects, floral induction, retention of blossoms, reproduction, propagation, etc.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
Small Phalaenopsis Taisuco Kaaladian plants were imported in late May and planted either in a mix consisting of 3 parts medium grade douglas fir bark and one part each of perlite and coarse canadian sphagnum peat (by vol.) or in chilean sphagnum moss. All plants were given 200 mg/L each of N and P, 100 mg/L Ca, and 50 mg/L Mg at each irrigation with 0, 50, 100, 200, 300, 400, or 500 mg/L K. After eight months, K concentration did not alter the number of new leaves on plants in either medium. Plants grown in moss produced four to five leaves, whilst those planted in the bark mix produced only 2 to 3 leaves. K concentration did not affect the length of the uppermost mature leaves when grown in the bark mix. However, in moss, plants had increasingly longer and wider top leaves as K concentration increased. The lower leaves on plants in the bark mix lacking or receiving 50 mg/L K showed symptoms of yellowing, irregular purple spots, and necrosis following spiking and
flowering, respectively. Yellowing and necrosis started from the leaf tip and/or margin and progressed basipetally. Symptoms became more severe during flower stem development and flowering. All of the plants lacking K were dead by the end of flowering. Leaf death originated from the lowest leaf and advanced to the upper leaves. K at 50 mg/L greatly reduced and 100 mg/L completely alleviated the symptoms of K deficiency at time of flowering. However, by the end of flowering, plants receiving 50 or 100 mg/L K had yellowing on one or two lower leaves. Plants grown in moss and receiving no K showed limited signs of K deficiency. All plants in the bark mix bloomed, whereas none in sphagnum moss receiving 0 mg/L K produced flowers. For both media, as K concentration increased, flower count and diameter increased. Flower stems on plants in either medium became longer and thicker with increasing K concentration. To obtain top quality Phalaenopsis with the greatest leaf length, highest flower
count, largest flowers, and longest inflorescences, it is recommended that 300 mg/L K be applied regardless of the medium. A study was conducted to characterize the response of Gaillardia aristata to three salinity levels (0.8, 2.0, or 4.0 dS/m) and four growing media: 100% perlite (Perlite), 1 to 1 (v/v) perlite and Sunshine Mix No. 4 (Perlite_Mix), 100% Sunshine Mix No. 4 (Mix), or 1 to 1 Sunshine Mix No. 4 and composted mulch (Mix_Mulch). The type of medium influenced dry weight (DW) of roots but not that of shoots. Shoot DW was higher in plants irrigated with tap water (0.8 dS/m) compared to those irrigated with saline solution at 2.0 or 4.0 dS/m, except for those grown in Mix. The root to shoot DW ratio was not altered by salinity but was highest for the plants grown in Perlite medium. Both medium and salinity affected plant height. Elevated salinity generally led to shorter plants. Plants were taller when grown in Perlite and in Mix_Mulch. However, plants had fewer lateral
shoots when grown in Perlite or Mix_Mulch.
Impacts
In recent years, a physiological disorder has been observed on Phalaenopsis leaves. The affected plants had irregular yellowish areas on the second and/or third basipetal leaves. The yellowed leaf tissues were found to have extremely low levels of K (0.40% to 0.64%). This physiological disorder had caused losses to both the suppliers and the downstream producers. The results of this study shows that potassium deficiency is a widespread problem in production greenhouses. It is suggested that, to obtain top quality Phalaenopsis with the greatest leaf length, highest flower count, largest flowers, and longest inflorescences, 300 mg/L K be applied regardless of the medium. Adequate potassium increases flower count and size, thereby enhances customer satisfaction. Gaillardia aristata planted in the landscape may be irrigated with reclaimed water having an EC up to 4 dS/m to save potable water. Although water at this salinity does not provide the best growth, in the
landscape where visual appearance rather than maximum growth is concerned, G. aristata may be irrigated with non-potable water at salinity up to 4 dS/m.
Publications
- Wang, Y.T., W.T. Tsai, and T.E. Dai. 2006. Heavy shading - An effective, low-cost alternative to high temperatures for inhibiting spiking in Phalaenopsis. Proc. 2006 Taiwan International Orchid Symposium. p:164-173.
- Huang, C.C., T.M. Shen, Y.T. Wang, and C.C. Huang. 2006. Studies on low temperature transportation of Phalaenopsis plants. Proc. 2006 Taiwan International Orchid Symposium. p:131-145.
- Niu, G., D. Rodriguez, and Y.T. Wang. 2006. Impact of drought and temperature on growth and leaf gas exchange of six bedding plant species under greenhouse conditions. HortScience 41:1408-1411.
- Wang, Y.T. and G. Niu. 2006. Long-term growth of live oak propagated from rhizomic shoot cuttings or seeds. Journal of Environmental Horticulture. 24:74-76.
- Wang, Y.T. 2006. Commercial production of potted orchids. OFA Bul. 899:1, 11-12.
- Wang, Y.T. 2006. Diatomite: Mineral salt retention and removal. Orchids 75:641-642.
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Progress 01/01/05 to 12/31/05
Outputs
Phalaenopsis is the most economically important orchids on the market worldwide. It is generally understood that warm temperatures accelerate vegetative growth and cool air promotes reproductive growth. Since Phalaenopsis performs crasulacean acid metabolism and incorporates CO2 mainly at night, learning how it responds to night temperature warmer than the day would help regulate its production. Phal. amabilis in 11.4-cm pots, having their inflorescences removed, were subjected to day/night temperatures at 30/25, 25/30, 25/20, 20/25, 20/15, or 15/20 C under a 12 h photoperiod of 140 mol m-2 s-1 PPF. After 4 months, the total length of new leaves was shorter as a result of fewer and shorter new leaves when nights were warmer than the days and as the average daily temperature declined. More spikes were produced at 25/20 and 20/25 C than at 20/15 or 15/20 C. In another experiment, Phal. amabilis plants were moved from a greenhouse to the above environmental conditions on
12 August. Plants that were exposed to 30/25 or 25/30 C had more leaf growth than lower temperatures, but no flowering. Those exposed to 25/20 or 20/25 C spiked in two weeks; but plants took 20 and 18 d to spike when exposed to 20/15 or 15/20 C, respectively. Again, as average daily temperature decreased, there was less leaf growth. Cooler day than the night reduced vegetative growth, regardless of temperature. Plants at 25/20 or 20/25 C had higher flower count (12) than those at 20/15 or 15/20 C (8). In a third experiment, plants of a large-flowered Doritaenopsis hybrid spiked in 22-24 d when exposed to 25/20 or 20/25 C, whereas 30-33 d were needed to spike under 20/15 or 15/20 C. In a fourth experiment, a Doritaenopsis hybrid spiked after 22, 21, or 25 d under 25/25, 25/20, or 20/20 C. However, 37 d were required to spike under 20/15 C. These results suggest that the best temperature range for spiking Phalaenopsis and the large-flowered Doritaenopsis is 25-20 C. In addition, a day
night temperature differential is not needed to induce flowering on these orchids when temperature is at or below 25 C.
Impacts
The information generated by my research provides means for developing new technologies to better control the emergence of the flowering stems in Phalaenopsis (spiking), which is the very first step towards flowering. Some growers feel that lower air temperatures would cause faster spiking and better flowering. My results show that lower temperatures not only resulted in delayed spiking, but also would increase production costs. When a suitable range of air tempeartures is used to induce spiking and grow the plants, they will be of higher flower count and better quality.
Publications
- Lopez, R., E. Runkle, Y.T. Wang, and M. Blanchard. 2005. The orchid grower. Greenhouse Grower September p:96-100.
- Wang, Y.T., M. Blanchard, R. Lopez, and E. Runkle. 2005. The Orchid Grower. Greenhouse Grower. August p:70-72.
- Runkle, E., Y.T. Wang, M. Blanchard, and R. Lopez. 2005 The orchid grower. Greenhouse Grower July p:64-67.
- Wang, Y.T. 2005. Temperature and Nutrient Effects on Phalaenopsis. Proceedings of 2004 Taiwan International Orchid Symposium. p:249-267.
- Wang, Y.T. 2005. Thermal effects on vegetative and reproductive growth of Phalaenopsis orchids. HortScinece 40:1014.
- Bichsel, R., Y.T. Wang, and T. Starman. 2005. Phyton 27 can cause phytotoxicity at low pH. Orchids 74:492-493.
- Blanchard, M., R. Lopez, E. Runkle, and Y.T. Wang. 2005. The orchid grower. Greenhouse Grower October p:86-89.
- Wang, Y.T. 2005. How lime and fertility affect a hybrid Paphiopedilum? Orchids 74:814-815.
- Wang, Y.T. 2005. Diatomite: A new material for growing orchids. Orchids 74:652-653.
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Progress 01/01/04 to 12/31/04
Outputs
Phal. amabilis in 11.4-cm pots, having their inflorescences removed, were subjected to day/night temperatures at 30/25, 25/30, 25/20, 20/25, 20/15, or 15/20 C under a 12 h photoperiod of 140 umol∙m-2∙s-1 PPF. After 4 months, the total length of new leaves was shorter as a result of fewer and shorter new leaves when nights were cooler than the days and as the average daily temperature declined. More spikes were produced at 25/20 and 20/25 C than at 20/15 or 15/20 C. In another experiment, Phal. amabilis plants were moved from a greenhouse to the above environmental conditions on 12 August. Plants that were exposed to 30/25 or 25/30 C had more leaf growth than lower temperatures, but no flowering. Those exposed to 25/20 or 20/25 C spiked in two weeks; but plants took 20 and 18 d to spike when exposed to 20/15 or 15/20 C, respectively. Again, as average daily temperature decreased, there was less leaf growth. Cooler day than the night reduced vegetative
growth, regardless of temperature. Plants at 25/20 or 20/25 C had hgiher flower count (12) than those at 20/15 or 15/20 C (8). In a third experiment, plants of a large-flowered Doritaenopsis hybrid spiked 22-24 d when exposed to 25/20 or 20/25 C, whereas 30-33 d were needed to spike under 20/15 or 15/20 C. In a fourth experiment, a Doritaenopsis hybrid spiked after 22, 21, or 25 d under 25/25, 25/20, or 20/20 C. However, 37 d were required to spike under 20/15 C. These results suggest that the best temperature range for spiking Phalaenopsis and the large-flowered Doritaenopsis is 25-20 C. In addition, a day night temperature differential is not needed to induce flowering on these orchids when temperature is at or below 25 C. Rhizomic shoot cuttings 25-30 cm long were taken from a single tree about 50 years old in late August 1990, rooted, and planted in 2.6-L pots after two months. During the same week, acorns were collected from the same tree and germinated. All trees were planted
into 13-L pots in July 1991 and then to a field in July 1992. Trees from both sources were planted either directly in the ground, in 36.6- or 45.7-cm diameter polypropylene fabric bags buried in the ground, or in 13-L pots on the ground. Trunk circumference 10 cm above the soil line was measured roughly yearly between 1992 and 1999. There were two trees per treatment, replicated eight times. Initially, trees from cuttings grew slightly slower than seedlings by having a smaller trunk circumference, diameter, and cross-sectional area. These differences diminished and all trees had similar circumferences after 1996. In 1992, trees in 36.6-cm bags and pots had more growth than trees in the ground. In 1993, trees in pots had better growth than those in the ground. After 1993, all trees had similar circumferences till the end of this study, probably due to roots extending beyond the bags and pots into the surround soil. About one-third of the seedling trees produced rhizomic shoots, whereas
none of the trees from cuttings did. The rhizomic shoots of trees in pots were contained within the pot and none from the ground.
Impacts
The information obtained in the orchid study is an initial step towards better understanding the environmental and other factors that control spiking and flowering of the Phalaenopsis orchids. The results of these experiments eventually will allow producers to better schedule and control flowering of Phalaenopsis orchids. Results from the oak study provide nurseries with a new technology to produce cloned live oaks with more desirable tree forms and uniform growth. These cloned trees do not produce sukers. Suckering of seedling live oak trees is a problem in ground maintenance.
Publications
- Wang, Y.T. 2004 Effects of reversed day/night temperatures on a Doritaenopsis hybrid. HortScience 39:834.
- Skaria, M., Y.T. Wang, and L. Barnes. 2004. What causes these spots. Orchids 73:54-56.
- Wang, Y.T. 2004. The China challenge. Phalaenopsis Journal 13(4):15-16
- Wang, Y.T. and L. Barnes. 2004. Bark and water molds. Orchids 73:368-370.
- Wang, Y.T. 2004. Flowering Phalaenopsis. Orchids 73:602-605.
- Wang, Y.T. 2004. Phalaenopsis as an international commodity. Phalaenopsis Journal 14(1):18-20.
- Wang, Y.T. 2004. Flourishing market for potted orchids. FlowerTech 7(5):2-5.
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Progress 01/01/03 to 12/31/03
Outputs
The 'Lava Glow' clone of the hybrid Doritaenopsis (Phal. Buddha's Treasure x Doritis pulcherrima) 15 cm in leaf span were subjected to day/night (12 h each daily) temperatures of 30/25, 25/30, 25/20, or 20/25 C at 170 umol m-2 s-1 PPF. After nine months, plants under the higher average daily temperature (ADT) produced more leaves. Those grown at 30/25 C had the largest leaf span and total length of the new leaves. Plants under 30/25, 25/30, 25/20, or 20/25 C had 5.0, 4.7, 3.6, and 2.8 new leaves and 72, 61, 42, and 28 cm in total new leaf length, respectively. Cool days and warm nights resulted in smaller leaf span and reduced leaf growth, particularly at 20/25 than at 25/30 C. Within a given ADT, cooler days resulted in shorter leaves. Leaves produced by plants at the lower ADT had a smaller length to width ratio and the more desirable oval shape. The most striking effect of 20/25 C was that 14 out of 15 plants bloomed, whereas only 5 plants under 25/20 C and none in
the 30/25 or 25/30 C treatment flowered. In a second experiment, 18-22 cm plants were subjected to 30/20, 20/30, 25/15, or 15/25 C. After 29 weeks, similar results were obtained. All plants under 15/25 C bloomed, whereas none in the other treatments produced flowers. Long-term exposure to 15/25 C resulted in slow leaf production and undesirable small leaves. These results suggest that, with day temperatures in the 20-15 C range, nights 10-5 C warmer are not desirable for rapid vegetative growth. However, cool days and warm nights may be used to effectively induce the onset of flowering stem elongation (spiking) in this Phalaenopsis hybrid Euphorbia pulcherrima 'Sonora Red' plants were treated foliarly with paclobutrazol at 40 or 80 mg L-1 one week following pinching, at the beginning of short photoperiod. After another four weeks, plants previously receiving the 80 mg L-1 rate were treated once foliarly with GA3 at 0, 10, 20, 30 or 40 mg L-1. The effect of GA3 was visible within 3
days of application. GA3 between 10 and 40 mg L-1 caused long internodes, excessive stem elongation, as well as small leaves and bracts, resulting in unmarketable plants. Plants that received 10 mg L-1 GA3 were nearly twice the height of the over-retarded plants (31 vs 17 cm), with increasingly taller plants at higher concentrations, up to 30 mg L-1 (40 cm). In a second experiment, single-stemed plants were treated with one foliar spray of 50 or 150 mg L-1 paclobutrazol two weeks following the beginning of short days. After another 3 weeks, the overdosed plants were then foliarly treated once with 0, 3, 5, 10, or 15 mg L-1 GA3. GA3 at all rates promoted stem elongation and resulted in large bracts and much increased inflorescence diameter. The 15 mg L-1 GA3 rate resulted in undesirable long internodes on the upper stem. Plants that received 3, 5, or 10 mg L-1 GA3 were of excellent quality, with their heights and inflorescence sizes similar to those of plants receiving 50 mg L-1
paclobutrazol (26 cm). Parallel experiments using 'Burgundy Cortez' had similar results.
Impacts
The information obtained in the orchid experiment is an initial step towards better understanding the environmental factors that control spiking of the Phalaenopsis orchids. The results of the poinsettia experiment have the potential to save the over-retarded plants frequently seen in nurseries.
Publications
- Wang, Y.T. 2003. Looking for an exotic pot crop? GMPRO 23(11):40-44.
- Wang, Y.T. 2003. Reverse osmosis water and slow-release fertilizer. Orchids 72:692-695.
- Wang, Y.T. 2003. Effects of N and P concentration on growth and flowering of the Phalaenopsis orchid. HortScience (abstract)
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Progress 01/01/02 to 12/31/02
Outputs
To determine the effect of various levels of phosphorus on growth and flowering of the Phalaenopsis orchids,bare-root plants were potted in a fir bark/peat medium and given 200 ppm N and 0, 25, 50, 100, or 200 ppm of P at each irrigation. When plants bloomed the following spring, neither flower size (9.2 to 9.8 cm) nor flower number (6.3 to 7.0) was affected. Leaf size stayed the same among all treatments. However, during the second year, as the P level increased from 0 to 25 ppm, there was a corresponding increase in flower number from 12 to 16. But futher increase in P concentration did not provide additional benefits. The 25 ppm P appeared to be adequate for producing good quality Phalaenopsis orchids. When P was at a fixed level of 200 ppm, increasing N concentration form 50 to 200 ppm at every irrigation increased flower number from 7 to 13. N at 400 ppm did not result in additional flowers to be produced. Paphiopedilum orchids were grown in a bark/peat medium
and given various levels of powdered dolomitic limestone. When the rate increased from 0 to 16 kg per cubic meter of medium, the pH of the medium was not affected. Paphiopedilum orchids appear to grow well when fertilized with 0.25 to 0.5 g per liter of a 20-10-20 fertilizer. Higher fertilizer concentrations resulted in leaf injury.
Impacts
The commercial potted orchid industry has become the second most valued floral crop since 2000. The information that is generated from this project has been used by commercial and hobby growers for producing better and more profitable plants.
Publications
- Wang, Y.T. and E.A. Konow. 2002. Fertilizer source and medium composition affect vegetative growth and mineral nutrition of a hybrid moth orchid. J. Amer. Soc. Hort. Sci. 127:442-447.
- Wang, Y.T. 2002. Nutritional requirements of Phalaenopsis orchids. Phalaenopsis Journal 12(1):14-17, 32-33. Wang, Y.T. 2002. Is it prosperous or phosphorus? Phalaenopsis Journal 11(4):8.
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Progress 01/01/01 to 12/31/01
Outputs
Unprotected flowers of the Phalaenopsis orchids wilt within 2 days after exposure to low levels of ethylene. The organic gas 1-methylcyclopropene (1-MCP) at 0.1 to 1.0 uL/L offered equal protection (flowers lasting 27-34 days) against ethylene. In another experiment, flowers treated with 0.4 uL/L 1-MCP and then exposed to ethylene after 7 or 14 days wilted within 4.5 days after ethylene treatment. However, flowers that were re-treated with 1-MCP after two weeks and exposed to ethylene lasted as long as the control flowers (50 days). In a third experiment, 0.5 to 1.0 uL/L 1-MCP protected flowers against ethylene for 6 but not 14 days. Therefore, the protection offered by treating orchid flowers with 1-MCP up to 1.0 uL/L was transient. It appears that unopened buds at time of 1-MCP treatment remained sensitive to ethylene after treatment. In the fourth experiment using excised flowers with no exogenous ethylene exposure, all untreated control flowers wilted within 2-3
days whether emasculated or not. Emasculated flowers pulsed for 24 hours with 0.5 mM AOA lasted for 6 days, while the non-emasculated flowers treated similarly lasted for 9 days. Emasculated and non-emasculated flowers treated with 1-MCP for 6 hours lasted 9 and 13 days, respectively.
Impacts
Flowers of a large percentage of blooming orchids being marketed in retail outlets are injured by low levels of ethylene, resulting in unsalable plants and huge economical losses. The results of these experiments can be used by orchid producers and retailers to protect orchids flowers and have the potential to save millions of dollars.
Publications
- Konow, E.A. and Y.T. Wang. 2001. Irradiance levels affect in vitro and greenhouse growth, flowering and photosynthesis behavior of a hybrid Phalaenopsis orchid. J. Amer. Soc. Hort. Sci. 126:531-536.
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Progress 01/01/00 to 12/31/00
Outputs
Orchid flowers are known to be extremely sensitive to low levels of ethylene, its exposure results in rapid flower closure. To determine the effect of 1-methylcyclopropene (1-MCP) on protecting orchid flowers against ethylene-induced closure, individually excised Phalaenopsis flowers were exposed to 1-MCP at 0, 0.05, 0.1, 0.2, 0.4, or 0.6 uL/L (ppm) for 12 h and then exposed to ethylene at 0, 2, 5, or 10 uL/L for 24 h. All flowers untreated with 1-MCP closed within 2 to 3 d, with or without exposure to ethylene. Flowers that were treated with 1-MCP between 0.1 and 0.6 uL/L lasted for 9 to 12 d at all ethylene levels, with no difference regarding to the concentration of 1-MCP. In a second experiment, cut Dendrobium flowers were exposed to 1-MCP at 0. 0.05, 0.1, or 0.2 uL/L and then to ethylene at 0.5, 1.0, 2.0, or 5.0 uL/L as above. Flowers not treated with 1-MCP but exposed to ethylene at any concentration all closed within 3 d. However, those treated with 1-MCP at
0.1 or 0.2 uL/L lasted similar to or longer (10 to 14 d) than the control (no 1-MCP, no ethylene; 11 d). Additional Dendrobium flowers were either exposed to 1-MCP or had their cut ends pulsed in a 0.5 mM solution of STS or AOA for 24 h and then exposed to 0.2 uL/L ethylene for 24 h. Flowers that were not treated with any chemical and those pulsed in AOA for 24 h closed in 1 to 3 d following their exposure to ethylene, while those treated with 1-MCP or STS lasted over 14 d. The protective effects of 1-MCP on intact, blooming Phalaenopsis will be determined.
Impacts
Potted, blooming orchid has become the second most valued floral crop in the United States. The new information and technologies developed by this project are published in scientific and trade journals and are made available quickly to producers in the U.S. and worldwide. Requests for reprints of my papers have been high.
Publications
- Wang, Y.T. 2000. Impact of high phosphorous fertilizer and timing of terminating fertilizing on a hybrid Phalaenopsis orchid. HortScience 35:60-62.
- Wang, Y.T. 2000. Medium, nutrition, and flower induction in potted blooming orchids. HortTechnology 10:433-434.
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Progress 01/01/99 to 12/31/99
Outputs
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). On 1 Sept., plants of flowering size receiving N, P, and K at 100, 44, and 83 mg/L, respectively, from a 20N-8.8P-16.6K soluble fertilizer were given N, P, and K, at 30, 398, and 506 mg/L (high P), respectively, at each irrigation 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 control (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.
Impacts
Market demand continues for longer lasting floral crops as well as new and unique plants for public use and greater grower profitability. Project research results in new technologies made available to the nursery industry to improve production, profitability, and consumer satisfaction. The project is also a leader in introducing and testing new, high-value crops.
Publications
- Wang, Y.T. 1999. Greenhouse performance of six potted anthurium cultivars in a subtropical area. HortTechnology 9:409-412.
- Cardenas, E. and Y. T. Wang. 1999. The effect of micronutrients and GA on the growth of Phalaenopsis seedlings in vitro. Subtropical Plant Science 50:45-48.
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Progress 01/01/98 to 12/31/98
Outputs
Aseptically raised young seedlings of a white-flowered Phalaenopsis orchid with one root and a single leaf were cultured on two media previously used by Hinnen et al. (1995) and by Duan and Yazawa (1995). The latter medium contains Hyponex and no other mineral salts. Each medium was used with or without the following supplemental micronutrients: 10 mg MnSO4 H2O, 3.0 mg H3BO3, 2.0 mg ZnSO4 7H2O, 0.75 mg KI, 0.25 mg Na2MoO4 2H2O, 0.025 mg CuSO4 5H2O, and 0.025 mg CoCl2 5H2O per liter of medium. Medium containing Hyponex promoted growth (heavier fresh weight and more and longer roots) over the Hinnen et al. medium when evaluated after 12 weeks. The addition of micronutrients to Hyponex and Hinnen et al. medium resulted in a tripling (1868 mg) and doubling (240 mg) of the fresh weight, respectively. In a separate experiment, supplementing GA3 at the rate of 1 mg L-1 to the Hyponex medium doubled seedling fresh weight after 16 weeks of subculture, while the addition of
GA4+7 at the same rate had no effect on seedling growth. Liners of six hybrid Anthurium cultivars, 'Pink Aristocrat', 'Patty Anne', 'Purple Viking', 'Royal Pink', Royal Orange', and 'Royal Red', from tissue culture were planted in pots and grown under warm (maximum 30 C) or hot (maximum 35 C) conditions with or without a single foliar application of 500 mg L-1 GA3 and evaluated after seven, nine, and thirteen months. GA3 did not promote Anthurium flower production. Plants in warm and hot areas, with the exception of 'Pink Aristocrat', had similar degrees of foliage injury in April, but those in the warm environment had better quality in July than those in the hot house. Yellow leaves and necrosis on leaf margins were apparent on plants in the hot area. 'Pink Aristocrat' was the most (over 20 flowers) and 'Royal Red' was the least (2 flowers) floriferous after one year. Flower color of 'Royal Red' was unaffected by high temperature, whereas flowers of the other cultivars faded under
heat. Growing these Anthurium cultivars at maximum 30 C air temperatures is recommended for good quality and high flower count.
Impacts
(N/A)
Publications
- Wang, Y.T. 1998. Deferring flowering of greenhouse-grown Phalaenopsis orchids by alternating dark and light. J. Amer. Soc. Hort. Sci. 123:56-60.
- Wang, Y.T. 1998. Impact of salinity and media on growth and flowering of a hybrid Phalaenopsis orchid. HortScience 33:247-250.
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Progress 01/01/97 to 12/31/97
Outputs
The effects of water salinity (0.05, 0.40, 0.75, 1.10, and 1.40 dS/m of electrical conductivity, EC) on Phalaenopsis orchids grown in 100% fine grade fir bark or a combination of 80% bark and 20% peat moss were studied. In both media, flower diameter decreased slightly as salinity increased. Plants in bark had more flowers as salinity increased, but had fewer flowers than those grown in bark/peat. In either medium, salinity had no effect on the number of new leaves produced. As salinity increased, plants in bark had increasingly larger total leaf area, with a maximum at EC = 1.10 dS/m. Leaf area of plants in bark/peat was greater than that of those in bark, but was unaffected by salinity. Root fresh mass was reduced with increasing salinity in both media. Media had no effect on mineral concentration in the leaf. In bark, increasing salinity increased the Ca and Na concentrations but had no effect on the concentration of other minerals in leaves. As salinity increased
in the bark/peat medium, leaf concentrations of P, Fe, and Cu decreased and those of K, Ca, Mg, Na, and Zn increased, but the concentration of N was unaffected by salinity. Leachate from bark/peat had twice the EC and lower pH (4.9) than bark (5.7). The application of a 20N-8.6P-16.6K fertilizer from March to October for two years doubled the yield of container-grown Aloe barbadensis. The lower leaves on the non-fertilized plants, particularly those with 18 leaves remaining, sometimes became desiccated or partially dry at harvest. The initial quarter yield and cumulative yield were higher in plants with 12 leaves remaining than those having 15 or 18 leaves. However, this trend disappeared over time. The fertilized plants produced an average of 10 kg/plant, while the non-fertilized plants produced 3.2 kg annually.
Impacts
(N/A)
Publications
- No publications reported this period
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Progress 01/01/96 to 12/30/96
Outputs
Starting 15 Sept. 1994, 2-year old Phalaenopsis TAM Butterfly seedling plants were exposed to repeated cycles of 1 day in darkness and another day in light (1D/1L), 4D/3L, 7D/7L, or 0D/7L (natural photoperiod control). Treatments were terminated on 16 Dec. The control plants bloomed on 20 Jan. 1995, whereas the 4D/3L plants did not reach anthesis until 14 Apr., nearly three months later. Flowering of the 1D/1L and 7D/7L plants was also deferred until early April. These treatments had no effect of flower count or size. Beginning 15 Sept. 1995, three-year old plants were exposed to weekly cycles of 0D/7L (the control), 2D/5L, 3D/4L, 5D/2L until 22 Jan. 1996. The control plants bloomed on 8 Feb. 1996 when the 5D/2L plants had just started spiking. The other treatments were not as effective as they were in 1994 and resulted in blooming only 2-3 weeks after the control. In a third experiment, starting on 22 Jan. 1996, plants were removed from a 5D/2L treatment, that was
initiated on 15 Sept. 1995, at two-week intervals and resulted in staggered anthesis. Plants that bloomed in May and June had reduced flower count, but not size. The effects of water salinity (between 0.05 and 1.40 ds/m-1 of EC) on Phalaenopsis orchids grown in 100% fine grade fir bark or a combination of 80% bark and 20% peat moss were studied. In both media, flower diameter decreased slightly as irrigation water salinity increased. Plants in bark, but not in bark/peat, had more flowers as salinity increased.
Impacts
(N/A)
Publications
- WANG, Y.T. 1995. A two-year study monitoring several physical and chemical properties of field-grown Aloe barbadensis Miller leaves. Subtropical Plant Science 47:34-38.
- WANG, Y.T. 1996. Medium and fertilization affect performance of potted Dendrobium and Phalaenopsis. HortTechnology 5:234-237.
- WANG, Y.T. 1996. Effects of six fertilizers on vegetative growth and flowering of Phalaenopsis orchids. Scientia Horticulturae 65:191-197.
- WANG, Y.T. 1996. Cytokinin and light intensity regulate flowering of Easter lily. HortScience 31:976-977.
- CHEN, W.H. and Y.T. WANG. 1996. Phalaenopsis orchid culture. Taiwan Sugar Sept.-Oct. 11-16.
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Progress 01/01/95 to 12/30/95
Outputs
One of six water-soluble fertilizers,10-30-20,15-10-30,15-20-25,20-5-19, 20-10-20, & 20-20-20 in N-P2O5-K2O,respectively,was applied to young seedlings of Phalaenopsis Tam Butterfly at concentrations of 200 or 100 mg N l-1. After 7 months,leaf span,leaf size,total leaf area,& shoot & root fresh weight were not different among various fertilizers within either concentration. However,plants had wider leaf spread,produced more & larger leaves,& had greater total leaf areas in response to the higher fertilizer concentration,regardless of which fertilizer was used. In a second experiment,the same fertilizers at the 200 mg N l-1 concentration were used on mature plants in late August,with either municipal water (EC=1.4 dS m-1) or water from a reverse osmosis system (RO, EC=0.03 dS m-1). Regardless of which fertilizer was used,flowering date,flower size & number,as well as plant width were unaffected. The 10-30-20 fertilizer resulted in 12% more leaves than 20N-8.7P-16.6K by
May the following year. When grown in bark, water with EC= 0.75 dS m-1 (a range of 0.05 to 1.40 tested) resulted in the latest flowering,compared to water having either higher or lower salinity. Plants grown in the bark/peat medium bloomed earlier than those in the bark & and were not affected by water salinity. Concentrations of N, Mn, and B in leaves were unaffected by salinity. As salinity increased from 0.05 to 1.40 dS m-1, tissue P,Fe,& Cu concentrations decreased,where concentrations of K,Ca,Mg,Na, & Zn increased.
Impacts
(N/A)
Publications
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Progress 01/01/94 to 12/30/94
Outputs
A preliminary test showed that the ground stem of a Crotalaria species, when used with 30% peat moss, provided good growth of Boston fern and hibiscus. The reduction of volume due to decomposition was less than Kenaf-amended medium. There was an indication that Crotalaria particles may provide better support to plants than ground kenaf after extended production period. A study conducted in growth chambers showed that the Phalaenopsis orchid require light while being exposed to cool air for spiking. Those subjected to 8 (mu)mol-m(superscript -2).S(superscript -1) or darkness did not perceive or accumulate the cooling effect required for spiking. However, additional cooling with light triggered all these plants to spike and flower. A technique for delaying flowering is being developed. The vegetative growth of the Phalaenopsis orchid was not affected by the six fertilizers tested. However, all fertilizers at 200 ppm N resulted more leaves and larger leaf are than those
receiving 100 ppm N. An experiment conducted in the summer of 1994 failed to induce apparent speckling, a physiological disorder, in golden pothos, regardless of low pH and high salt level in some media. A lime rate as high as 11 kg.m(superscript -3) failed to maintain medium pH above 5.5. Medium pH in most media dropped to below 4.6, some less than 4.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
The second season following treating Phalaenopsis plants with various growth retardants, flower spike emergence and flowering date were progressively delayed by increasing concentrations of paclobutrazol and uniconazole. Neither retardant affected flower number or size. Dipping plants in paclobutrazol or spraying with paclobutrazol or uniconazole accelerated the production of progressively smaller leaves as concentration increased. Paclobutrazol was more effective on shortening flower stalk when spayed on plants before spike emergence. Its effect decreased when treatment was delayed. Paclobutrazol concentrations between 125 and 500 mg.liter(superscript -1) had little dosage effect on flower spike length. During a second season, five media resulted in no difference in plant performance. Increased fertility, from 50 to 200 mg.liter(superscript -1)N, promoted early flower spike emergence and flowering. Higher fertility caused a linear increase in flower number, spike
number, spike diameter, and leaf number and size. One application of GA(subscript 4+7), at 100 ppm, two applications of 50 ppm four weeks apart, and four applications of 25 ppm every two weeks were effective in partially restoring stem elongation of plants dwarfed by uniconazole. The size of individual leaves, but not stem diameter, increased following GA application. Uniconazole resulted in short pedicels with increased diameter, as well as large pith, vascular, and cortical tissues than the untreated control.
Impacts
(N/A)
Publications
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Progress 01/01/92 to 12/30/92
Outputs
Fifteen weeks after budding `Queen Elizabeth' on a thornless mutation of Rosa odorata (RO) rootstock, over 80% of the buds had developed into shoots; whereas only 60% of the buds on the Rosa multiflora (RF) rootstock were growing. During the next five years in a field with alkaline soil (pH (double tilde) 8.4), plants on RM showed severe chlorosis and had 0% and 15% survival for those produced in 2.6- or 5.2- liter pots, respectively. The leaves on plants budded onto the RO rootstock remained green and had 90% and 80% survival when initially produced in 2.6- or 5.2-liter pots, respectively. Phalaenopsis seedling plants in a perlite/Metro Mix/charcoal (1:1:1) medium had superior root system but had slight fewer flowers than those produced in a perlite/rockwool (1:1) medium. The latter medium resulted in smaller flowers and thinner stalks. Fertilizer level (50, 100, or 200 ppm from Peters 20N-8.6P-16.6K with each irrigation) had no effect on days to bloom or flower size.
Increasing fertilizer concentration resulted in more flowers, larger and longer flower spikes, and faster leaf production. Dipping the entire Phalaenopsis plants in paclobutrazol (0, 50, 100, 200, or 400 ppm) or uniconazole (0, 25, 50, 100, or 200 ppm) did not affect days to bloom, but effectively resulted in shorter stalk length. When applied foliarly, the results of these retardants were limited. Flower size and number were not affected by treatment.
Impacts
(N/A)
Publications
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Progress 01/01/91 to 12/30/91
Outputs
Unrooted cuttings of Hibiscus rosa-sinensis L `Seminole Pink' was dipped for 5 sec in solutions containing 0, 25, 50, 75 or 100 mg/liter of uniconazole (UNI) or paclobutrazol (PAC), rooted, and then potted. UNI was more effective than PAC in suppressing stem elongation and the number and length of lateral shoots. Flowering was delayed by the highest rate of UNI. Flower number was reduced by both chemicals, without effect on flower size. UNI resulted in short pedicel where PAC had no effect. Applying UNI (50 mg/liter) to axillary buds or the green bark below a bud immediately after pruning limited elongation of the first three internodes of the new shoot. When UNI was used on plants with 24 day old shoots, 40 mg/liter applied to the whole plant provided the only satisfactory height control. GA(subscript 3) (50 mg/liter) was more effective in promoting elongation of shoots previously retarded with a drench application of UNI (0.1 mg/2.6-liter pot) when applied to the
whole shoot, leaf blades, or shoot tip. Application of GA(subscript 3) only to the stem surface, whether old or young, did not effectively encourage the growth of shoots previously retarded with UNI. Radermachera sinica grew satisfactorily in media with 25% or 50% composted cotton waste (CW).
Impacts
(N/A)
Publications
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Progress 01/01/90 to 12/30/90
Outputs
Rhizomic shoots of live oak were rooted 100% with IBA concentrations ranging between 0.125% and 1%, with rooting occurring faster at successively higher concentrations. Untreated cuttings had only 58% success after 100 days. All hydrophilic polymers retained less water in the presence of metal ions in the soaking solution, with substances releasing Fe being the most detrimental. The amount of water being held in pots amended with a hydrophilic polymer decreased after repeated fertilization. Medium volume increased with increasing amounts of the polyacrylamide in the base medium. Medium bulk density, total water retention and water retention per unit volume of medium were increased by the incorporation of the polyacrylamide hydrogel. Non-capillary porosity measured at container capacity in medium amended with Micromax progressively decreased as the amount of hydrogel increased, but remained unchanged in medium without Micromax. When used on plants with 24-day old
shoots, uniconazole (40 mg-liter) applied to the whole plant provided the only satisfactory height control. Leaf size was reduced by nearly 50% with a concomitant increase (12%) in fresh weight per unit area. GA(3) (k/ mg-liter ) was more effective in promoting elongation of shoots previously retarded with a drench application of uniconazole (0.1 mg/2.6-liter pot) when applied to the whole shoot, leaf blades or shoot tip.
Impacts
(N/A)
Publications
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Progress 01/01/89 to 12/30/89
Outputs
Plant height, number of leaves and flower buds, shoot diameter, and leaf size of"Jane Cowl' hibiscus decreased with increasing rates of uniconazole. Leaf chlorophyll concentration increased with higher rates of uniconazole, but dark respiration remained unchanged. Development of secondary xylem tissue, transverse diameter of vessel elements, and number of size of phloem fibers were suppressed by uniconazole. Uniconazole had no effect on the growth of cuttings taken from stock plants 145 days after treatment. Soaking unrooted "Seminole Pink' hibiscus cuttings in uniconazole solution was more effective in suppressing extension growth, number and length of lateral shoots than paclobutrazol. Flower size was unaffected regardless of the type of retardant. Apical meristems of plants receiving uniconazole at 0.1 mg.pot were wide and flat, whereas untreated plants had narrow, conical shaped apices. Cells in the subapical region of treated plants were larger and less organized
than the control. Water retention by all hydrophilic polymers tested was reduced in the presence of metal ions and fertilizers in the soaking solution, with substances releasing Fe being the most harmful. Medium bulk density, total water retention, and water retention per unit volume of medium increased by the incorporation if the polymer, regardless of the addition of micronuients to the base medium.
Impacts
(N/A)
Publications
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Progress 01/01/88 to 12/30/88
Outputs
A synthetic hydrophilic polyacrylamide polymer was found to have no interaction with a slow release fertilizer on the shoot growth of Chlorophytum comosum during winter greenhouse production. The polymer did not affect the top growth of Plectranthus australis, but more than doubled the root weight. Another polyacrylamide polymer was found to increase the water-holding capacity of the medium on a per pot and a per unit volume basis, while the non-capillary pore space of the medium decreased slightly. Severe leaf abscission on Radermachera sinica in the retail outlets was found to have been induced by the exposure to low levels of ethylene in the store atmosphere or during transit. Application of silver thiosulfate (STS) solution at a concentration of 0.125 mM on the foilage protected the leaves fron being damaged by ethylene. STS concentrations at and higher than 0.5 mM caused phytotoxicity resulting in unsalable plants when greenhouse air temperature was high.
Application of a growth retardant, Uniconazol, on tomato transplants offered effective height control. Plants received a soil drench of Uniconazol were shorter than plants which received a foliar application at similar doses, following four months of production in a greenhouse. Plants received low rates of Uniconazol as a foliar spray one day prior to transplanting had similar total fruit yields as the non-treated plants, but had much less fruits with blossom-end rot and more large fruits.
Impacts
(N/A)
Publications
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Progress 01/01/87 to 12/30/87
Outputs
Chlorophytum comosum and Nephrolepis exaltata were grown in media amended with apolyacrylamide hydrogel material at 0, 1 or 2 times the recommended rate. Top and root growth of C. comosum were enhanced by 50% over the control when grown at the high hydrogel rate. Plant water use efficiency was greatly enhanced by the high rate of hydrogel. Growth of N. exaltata was unaffected by this hydrogel. Another hydrogel made of starch grafted potassium propenoate-propenamide copolymers did not improve the growth of Codiaeum variegatum and Dieffenbachia camille. The latter hydrogel is more subject to damage caused by cations, particularly ferric ions. As single node leaf-bud golden pothos cuttings were taken from the second apical node basipetally to node 14, days to first leaf unfolding increased. Faster growth of the axillary shoot, more leaves, longer stem, larger leaf area and greater shoot fresh weight were associated with cutting from the more apical nodes. Shoot
growth was accelerated when cuttings had a 3 cm or longer internode below the nodes and had retained a 6-8 mm section of the old aerial rootx. Beaucarnea recurvata grown in media with less air space had greater growth than plants in a peat-lite medium, but required more frequent irrigition. Plants had less growth at 27% full sun than those grown under 50% or 30% full sun. Constant fertilization did not affect plant size but decreased medium pH and increased electrical conductivity of medium leachates.
Impacts
(N/A)
Publications
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Progress 01/01/86 to 12/30/86
Outputs
Foliar spray of benzyladenine (BA) at rates of 250-2,000 mg 1 to Syngonium podophyllum 'White Butterfly' cuttings at 3- and 5-leaf stages promoted lateral branching and shortened internodes on the main shoots, resulting in bushier and more compact plants. However, the total number of lateral shoots was unaffected by BA application. Plants sprayed with BA had greater fractions of total dry matter, which was not affected by BA, in the lateral shoots. Ancymidol soil drenches at 0.25, 0.50, 0.75, and 1.00 mg pot reduced plant height at the end of production period. Total length of the top 3 internodes was reduced to 50%, 30% and 25% of control by 0.25, 0.50 and higher rates, respectively. Ancymidol induced more lateral shoots. After 10 weeks in a simulated interior environment, plants treated with ancymidol were shorter and more compact; however, their new petioles were 20% longer than the controls regardless of the rates. Light intensity at 290 umol.s.m and warm
medium (28C) enhanced both shoot and root growth of Epipremnum aureum leaf-bud cuttings compared to 60 umol.s.m and unheated medium (10-16). Leaf-bud cuttings needed 10 more days to unfold their first leaf compared to stem cuttings without parent leaves. Shoots developed from leaf-bud cuttings had much longer stems, more leaves and total leaaf area of heavier dry weights than shoots from stem cuttings.
Impacts
(N/A)
Publications
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Progress 01/01/85 to 12/30/85
Outputs
A propagation study showed that higher light level (73% vs 92% light exclusion) and bottom heat at 29C during rooting of Codiaeum variegatum improved root grade and plant growth after transplanting. Although bottom heat greatly enhanced root grade on Ficus benjamina cuttings, it did not have any effect on subsequent shoot growth. Light exclusion during storing of croton 'Craigii' cuttings did not have detrimental effect on their quality. Disease-free cuttings could be shipped in complete darkness at temperatures between 15C and 20C for 15 days or at 30C for 10 days with good quality. Extended exposure of croton cuttings to temperatures above 30 or below 15 should be avoided. Five minutes preplant soak of Syngonium podophyllum 'White Butterfly' single node cuttings in 400 and 800 ppm PBA solutions slightly accelerated bud break, but, later shoot establishment was greatly delayed. As PBA concentration increased, plant height, width, and leaf number all decreased.
New shoots from cuttings with their parent leaf blades attached were much bigger than those from cuttings without the parent leaf blade. Light level on stock plants did not significantly affect shoot and root regeneration. Five minute soak of Epipremnum aureum 'Golden Potho' leaf-eye cuttings in BA solutions from 0 to 750 ppm did not affect leaf number on the new shoot, however, vine length was much reduced at BA concentrations above 250 ppm.
Impacts
(N/A)
Publications
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