The speaker's tour by Brian Rittershausen was well received, and thanks to Landis Stanlake the travel arrangements worked smoothly. Landis is now busy planning for next year's speaker.
The Conservation Committee continues to work on major projects, including the collection of slides of native Canadian orchids, and the Education Committee will be sending out a survey to gather information on how members grow their Cattleyas. The information forwarded to them will be collated and published in a future COC newsletter.
We are looking forward to seeing all COC representatives and board members May 3rd and 4th at the 1997 annual COC meeting in Regina.
Happy New Year
This article was given as a presentation on April, 1996 in Vancouver to the Odontoglossum Alliance Meeting held in conjunction with the AOS Trustees meeting.
by Marilyn H.S. Light, University of Ottawa, Ottawa, Canada, K1N 6N5
For the past fifteen years, I have been working primarily with temperate terrestrial orchids. Because the seeds of these species have up until recently proved a challenge to germinate, and because I often require germinable seeds for flasking courses, I began experimenting with the seeds of tropical orchids. While there have been many articles and books published concerning the propagation of the more common orchids, there still is a paucity of basic information about the many less popular orchids. I have accumulated some information regarding the habits of particular orchids I have grown but mine is a relatively small collection, so it has been through contacts with growers that I have been able to gather more data than I could ever possibly accumulate alone. I believe that one of the greatest tragedies of extinction is that we stand to lose forever the opportunity to learn what a particular species has to teach us. I hope that readers will willingly share what they know, particularly about capsule maturation and behaviour of the less common species, so as to make our conservation and hybridization efforts even more productive.
Working with a wide variety of plants can sometimes provide insights not easily found in a more narrow approach. For example, we have recently reported germination polymorphism in Epipactis helleborine, a European colonizing orchid now widespread in the United States and Canada. Common, weedy, but notoriously difficult to germinate, this orchid may provide the 'window' we need to better understand orchid reproduction. We have found that certain plants of E. helleborine and even particular flowers within an inflorescence produce seeds that germinate quickly and without any need for stratification while others produce seeds which germinate differently. Furthermore, we have discovered that flower position within the multi-flowered but unbranched inflorescence may influence self-compatibility: lower flowers are self-compatible whereas upper flowers are not. These observations would not have been possible if the seeds had been uniformly easy to germinate: differences would not have been apparent. Interestingly, parallel studies with Cypripedium calceolus var. pubescens (C. parviflorum v. pubescens) have shown that in some instances, flower age at pollination can affect seed production outcomes. While the reasons for the observed orchid reproductive behaviour are not yet clear, these and other anecdotal observations with, for example, Catasetum, has led us to investigate whether there is any effect of flower age and flower position on seed production outcomes in other orchids such as a member of the Oncidiinae.
Some of the principal challenges to orchid seed production are 1) which parents to use and/or which flower to pollinate, 2) when to pollinate, and 3) when to harvest the seed. After seed is successfully produced, further questions arise. Should the capsule be harvested prematurely or at dehiscence? Which medium should be used to germinate the seed? And once the seed has germinated, when and on which medium should the protocorms be replated?
Effect of flower age at pollination and flower position on fruit set To determine whether there is an effect of flower position and flower age at pollination on seed production outcomes of Oncidium ornithorhynchum, we developed a balanced experimental design and randomized treatments. This orchid produces flowers that normally last 15 - 20 days. Buds open in somewhat a reverse order from the top of the inflorescence downwards. Flower buds on two inflorescences were assigned numbers before they opened and randomly selected positions were designated for pollination at 0, 7 and 14 days post-anthesis (after the flowers opened). Pollen from another plant was used for all pollinations. We found that the most significant factor affecting fruit set in Onc. ornithorhynchum is the age of a flower at pollination (P = 0.02). Four of six flowers pollinated at anthesis set fruit whereas only one of five flowers pollinated seven days after opening set a capsule. In the latter case, the capsule was smaller in diameter and contained fewer seeds: many embryo sacs in arrested development were observed. No flowers pollinated 14 days post-anthesis set fruit. The effect of flower position was mixed. The results suggest that flower position or more precisely, order of flower opening may influence capsule set outcomes but more extensive experimentation will be needed to test this hypothesis. The experiment should be repeated with up to ten different plants to be able to generalize the observed effect of flower age for this species.
It was W.W. Goodale Moir who stated "We are firm believers in using flowers as they open.... (Moir & Moir, 1980). I understand from conversations with growers/hybridizers including Bob Hamilton, Helmut Rohrl, Raul Sudre and Wally Thomas that they normally choose the lowest flowers first when pollinating species or hybrids of the Oncidiinae. Why? The most frequent response given was that of a strategy whereby if a lower flower failed to set seed, other flowers were still available for pollination. No one kept a record of exact flower age at pollination but it was generally agreed that fresh flowers were chosen over older blooms.
The Odontoglossum-Oncidium alliance is broadly clustered about three main capsule maturation scenarios: 1) maturation in 60 - 90 days as in Tolumnia variegata; 2) maturation in 100 - 150 days as in Miltonia clowesii and Oncidium flexuosum; and 3) maturation taking more than 180 days and in some cases up to one year as in Odontoglossum crispum and Trichopilia suavis. While most Tolumnias behave similarly, other genera are not nearly so consistent particularly in a geographically widespread genus such as Oncidium. Furthermore, plants of the same species raised under different environmental conditions can behave differently. Charlie Baker (Oregon) reported that Miltonia spectabilis capsules take 240 days to dehiscence while Raul Sudre (Brazil) reported 156 days for the same species. Is the difference due to environment or is it merely a clonal habit? Whatever the reason, one must rely upon experience as to when to harvest an entire capsule containing mature seed when no other guidelines are available.
One method that can be used to monitor capsule maturation is the step-wise enlargement of a capsule over time. Measurement of capsule girth at weekly intervals can roughly account for the time of fertilization (40 - 60 days after pollination in most genera other than Tolumnia), the period of rapid embryo development (80 - 240 days) and the beginning of seed maturation prior to dehiscence. The capsule enlarges after pollination, stops growth during the fertilization interval then resumes growth while seeds are developing until maximum girth is reached. The capsule may sit in this state for many weeks or months before splitting and therein lies the challenge. How long can one allow the capsule to mature before it suddenly splits and seed is lost? A method that relies or subtle changes in fruit appearance or colour just prior to dehiscence is one way to avoid disaster but one has to be paying attention to their plants to use this method effectively A capsule may become dull, yellowish or the capsule sutures may become pale just prior to splitting. Hybrids, especially intergeneric hybrids can be somewhat unpredictable but apart from some reluctance to split naturally, these capsules will follow a step-wise development scenario. The overall tendency is to follow a pattern and timetable similar to that of the seed parent.
One of the most frequently asked questions about germinating seed is whether it is preferable to harvest an entire mature capsule, to collect mature seed only when a capsule splits, or to attempt embryo culture by harvesting a green capsule sometime after fertilization has happened. There both advantages and disadvantages with any choice. My preference and that of most hybridizers is to harvest a fully mature but entire capsule. The seed within the capsule is uninfested by bacteria or fungi thus seed sterilization procedures are not needed. Furthermore, free-flowing seed may be more easily distributed in flasks. Any remaining seed is fully mature and so may be saved for future use or for exchange. Immature seed cannot be safely dried or saved and if harvested at an inappropriate time, the opportunity for propagation is lost.
Sometimes capsule development can unduly stress the seed parent. Can one remove the inflorescence and developing capsule to save the plant but still get some of the precious seed? I have observed with Rossioglossum grande that an inflorescence carrying one capsule cut from the plant 150 days after pollination and placed in water continued the seed maturation process. The capsule remained green for a further three months when it showed signs of imminent splitting. The seeds were then harvested, flasked and germinated well. This approach may work with other species or hybrids but is suggested only when no other option is available.
Another Popular FAQ concerns medium choice to germinate seeds. I polled other growers and received as wide a response as one could want. Some use Knudson's 'C' medium for liquid culture, the others use a tomato juice, sugar and agar mixture. I had votes for Hill's Medium, Murashige & Skoog formulations, and various G & B media. Clearly there are many workable options and personal preference plays a big role. Many popular recipes contain additives such as banana and/or coconut water but the most popular additive is activated charcoal (0.2%). Charcoal seemed to be particularly useful with some of the more challenging species such as Rossioglossum grande and Psychopsis papilio but it seems to be most important as a medium component at the replating stage.
A small amount of seed was obtained courtesy of John Law. This desirable equitant orchid is threatened in its range state of Hispanola and not particularly common in cultivation. My goal was to germinate as much of this precious seed as possible yet I could not find any guidelines in the literature as to which medium to choose. One approach when working with uncommon species and background information is to sow small amounts of seed in replicate on at least two or on several different media. I chose media I believed would bracket the requirements for the species and included formulations with and without charcoal. Coconut water is a natural although uncontrolled source of the plant hormone kinetin which has sometimes proven helpful in stimulating seeds to germinate. This component was added to both classes of media as was banana. Seeds were surface sterilized with 1:10 bleach for ten minutes followed by a one minute rinse with sterile water. Replicates were sown on four media including Murashige & Skoog Medium M 9274 (Sigma), quarter strength, with added sucrose (20 g/l), agar (8 g/l), pH 5.6, with either added banana (80 g/l) or added coconut water (100 ml/l). These formulations do not contain charcoal. The two other media tested were Phytamax P6668 (Sigma) with agar (8 g/l) and either added banana (80 g/l) or added coconut water (100 ml/l). Phytamax P6668 contains peptone and more thiamine than the M & S formulation while M 9274 contains glycine. Seeds germinated within 15 days and to the greatest extent (43%) on the Murashige & Skoog medium with added coconut water but the protocorms were pale and developed slowly. No seeds germinated on MS medium with banana. Germination on the Phytamax media was slower, 23 to 25 days, and quantitatively less than with the Murashige & Skoog media (31% with banana; 14% with coconut water) but growth was superior. Up to three true leaves developed on most seedlings within three months of sowing. Pale protocorms removed from the Murashige & Skoog mother flasks were replated onto either of the Phytamax - based formulations tested where they quickly recovered vigour. If maximum percent germination is desired, I suggest that seeds of Tolumnia henekenii could be germinated on 1/4 strength M9274 with added coconut water or an equivalent formulation then replated after a few weeks onto P6668 with added banana for superior growth.
TO BE CONTINUED
I started growing orchids almost 20 years ago and like everyone else I started with one plant. At that time I didn't know anything about orchids and their cultural requirements. Also, there was limited information available, It took me almost one year to find out about an orchid society. Now I am usually able to keep my orchids alive and growing and as a bonus I get them to flower!
Orchids have been cultivated for centuries by the Chinese. The first tropical orchids arrived in Europe around 1750. By the l9th century orchidmania captivated Europe's wealthy and gradually they were learning how to grow them. They had to rely on information sent back to them by their collectors as to the conditions that the plants were growing in, since orchids can be found on every continent except the Antarctic and from sea level to 4200 m (or 14,000 ft.). Almost 90% are found between the tropics of Cancer and Capricorn and out of that 95% are epiphytes meaning that they use a tree for an anchor. The other 5% are terrestrial or grow on the ground.
Orchids are also divided into two different growth habits: the first, monopodial with a single stem growth that increases in height indefinitely - examples would be phalaenopsis or vanda; the second, sympodial where there is a limited stem growth and new growths form from a creeping rhizome - examples are cattleya and paphiopedilum. The flowers are designed to attract a pollinator - some use shape to imitate an insect, others use colour or fragrance. Each orchid species relies on a different pollinator which is why there is such a wide diversity in orchid flowers.
Most people starting to grow orchids begin to grow them in the house. All orchids have three basic requirements and the secret to successful growing is to find the correct balance of the following:
Most orchids grow in medium light conditions - 2,000 to 3,000 ft. candles; however there are some that will do well in brighter south sunlight and quite a few that do well in lower light of about 1,000 ft. candles. In order to provide the correct lighting you need to know where the species grow, or if a hybrid, where the parent species grow. This will give you a clue as to temperature. The sunlight also provides heat and this combination is the principle for growth in all plants. Like us, orchids should be warmer during the day and cooler at night when they are converting sugars into plant cell growth. With regards to light, the plants make the most use of the red and blue ends of the spectrum, so when growing under lights make sure that the bulbs incorporate these colours. When growing on a windowsill, ensure that the direction of light is compatible to the type of orchid you want to place there or you may have to provide some shading from the long hot summer sun.
Day length is also a factor in orchid plant growth. Since most orchids are found between the tropics, 11.5 to 12.5 hours of light would be normal. As mentioned earlier, nighttime is essential to convert sugars, because of this I have found that the most rapid growth occurs in the spring and fall. It is an advantage to grow under lights since you can control light and temperature. Temperature can be divided into three groups:
Day Temperature Night Temperature Cool 70F (20C) 55F (12C) Intermediate 80F (25C) 65F (17C) Warm 90F (30C) 75F (22C)
If you are growing in a greenhouse or sunroom make sure that the temperature does not rise above I00F or 40C, or drop down to 40F or 5C since orchids, like ourselves, do not do well at very high or freezing temperatures.
All plants take in oxygen and carbon dioxide. These are absolutely essential to plant life. This means that all growing areas need ventilation and fresh air. During the day plants give off oxygen. (The reason greenhouses smell so good.) Outdoors them is always some air movement even though there may not be any wind there is always convection currents gently moving the air This prevents fungus infections. Always have a fan moving the air across your plants, not at hurricane force but with a gentle movement.
What is the correct humidity? This is more difficult to define - somewhere between a desert and 100%. Every species is found in its own micro-climate. The cooler your growing area the easier it is to increase the humidity. Most orchids enjoy having their roots exposed to humid air. A good average is around 70%, which is too high for indoor culture. In order to compensate, set orchid plants on a pebble tray thereby creating a micro-climate around your orchids. Do not submerge your pot into water as this will rot the roots and kill your plant. Another factor is the higher the humidity the less frequency of watering.
During long hot summers the frequency of watering will be higher as will the volume. During the winter months you can probably cut the frequency in half. Everyone has a different environment. You will have to adjust your watering schedule according to your conditions. As a starting point in the home, water your orchids every three or four days during the summer and every six to seven days in winter. As mentioned earlier, orchids enjoy high humidity, so during the winter months when our humidity is 0%, orchids enjoy a daily misting preferably early in the day so they can dry out by nightfall. The quality of water can be a major factor in being successful with orchids. If the mineral content is high and the water hard, use rain water, melted snow, or distilled water. Always allow the water to reach room temperature prior to using and never use water that has been purified with chemicals since the chemicals may be harmful. If the hardness of your water is lower than 150 ppm, then it is fine to use. Always water so the water comes out of the bottom of the pot. This ensures that the salts from the fertilizers are leached out. Fertilizing is the second part of watering. I always fertilize every watering but only at one quarter the recommended strength. Because orchids are not grown in soil, they require a little bit of food all the time.
A few other points to remember. It is important to repot orchids at least once every two years. Some miltonias need to be done every year. The principal medium used is a mixture of three pans orchid bark, one pan charcoal and one part perlite. Always wash the components prior to mixing as they are quite dusty and the dust will plug the hairs on the roots, eventually killing the plant. The charcoal will help keep the mixture sweeter and the perlite will keep it open as the bark will eventually decompose. Insect problems do happen so a constant visual inspection for signs of pests needs to be done. There are a number of commercial pesticides for ornamentals which may be suitable for orchids.
Mike Gabrielson, owner of Martin Orchids in Edmonton, is currently growing about 10,000 orchids in his nursery. His main interest is in species of which he has about 3,000, or approximately 10% of the world's known species.
A while ago, someone gave me a book about orchids (of course). It is not a very new book, published in 1974 and written by Prof. K.H. Meyer. It contains extraordinarily beautiful colour plates of orchids painted by Kurt Beyer. These pictures alone would be sufficient to make this a wonderful addition to anyone's orchid library. However, Prof. Meyer has a way with words and writes many informative tales from bits and pieces connected with our increasing knowledge of the orchids.
One particular sequence I want to share with you here, albeit in a somewhat shortened form; it concerns terrestrial orchids from our northern climates: He states that the seed grain of an orchid does not contain an embryo plant, as can be found in other seeds. The very small orchid seed will eventually land on the ground and optimally will be exposed to alternating conditions of moisture and dryness. In time, the covering cells will be softened sufficiently to allow fungal growth to enter and attach itself to the seed. Only then will the cells begin to divide (the fungus supplying the food) to form a minute, rotund body called a protocorm. This pin-head sized grain has thin, root-like hairs all around its base and will stay in the ground, quite happily for four to six years in some cases. This same result will happen inside a sterile flask, without fungi, but a nutrient solution feeding the protocorm. I have read that it can take between two to eight years before the protocorm decides that the time is right to change, to begin growing stem and leaves, to emerge into the light. Prof. Meyer informs his readers that it takes a Cypripedium sixteen years from sowing to flowering!
Alright, you say, that is not really new; but now comes what surprised me: Under adverse conditions the orchids won't rise above ground. For instance, if the surrounding forest grows too tall to admit sufficient light, the plants will at first stop making flowers, then their stems and leaves will become smaller and eventually - as Plantae hypogaeae - they will remain underground, reverting to a subterranean stage, depending again on the fungi for food. These orchids have NOT died out - they are waiting for better conditions. And if some of the trees were to fall, creating a sunny opening, the orchids would reappear. This incredible adaption to such different conditions is called 'Intermittation' . Thus we can, at times experience great 'Orchid Years' where these wild flowers will grow in lovely abundance. How - asks the Professor - can we then tell the age of a wild orchid? We cannot. We must only stand in awe before such wonders, and we all will, now more than ever, admire and enjoy the miracle of an orchid.
by Ingrid Schmidt-Ostrander
For the past year and a half the Orchid Species Preservation Foundation of Alberta has been raising funds for the construction of a greenliouse at the Muttart Conservatory to house the Orchid Species Collection, which presently consists of approximately 5000 plants. The Collection is currently spread through several greenhouses located at the north end of the Conservatory complex.
In the past year we have succeeded in obtaining substantial funding from the Edmonton Community Foundation to supplement existing funding provided by the Orchid Species Preservation Foundation and the City of Edmonton. We are pleased to report that on Friday November 1, 1996 we received a cheque in the sum of $73,740. 00 from the Alberta Provincial Government representing the remainder of funds needed to begin construction of this project ( in excess of $140,000.00). We understand that construction of the greenhouse will commence in The spring of 1997 and that the project will be completed during the year.
The Orchid Species Foundation wishes to extend its warmest thanks to its members and those of the Orchid Society of Albena, as well as the City of Edmonton, the Edmonton Community Foundation and the Provincial Government fbr their support of this project.
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