by admin | November 26, 2020 12:06 pm
Sheryl attended a presentation given by Jim at a local library on the Big Island of Hawaii in September 2009 and then visited the farm. This article is a summary of the library presentation and the farm tour.
Jim and Tracy Reddekopp are the proprietors of the Hawaiian Vanilla Co. They live with their five children on a 25 acre farm in Paauilo, Hawaii, on the Big Island’s northeast Hamakua Coast and grow and produce 300 pounds of vanilla a year using organic farming methods. Their knowledge of vanilla cultivation and production has been gleaned through years of experience, sometimes by trial and error. Their original vanilla plants were propagated by meristemming or tissue culture. In broad terms, this involves taking tissue from the newest apical growth of a ‘stud’ plant in the greenhouse, and using that tissue to create more plants. While it is a clean way to do it, it is also the slowest. Their new plant material is now obtained by re-planting cuttings from existing established plants.
General facts about Vanilla
Veracruz, Mexico is the birth place of vanilla. It was first cultivated by indigenous Totonaca Indians. The plant from which vanilla is derived is an orchid of which there are over 120 different varieties. However, only two of these are cultivated for commercial production: Vanilla planifolia, the variety that is grown at Hawaiian Vanilla Co and commonly referred to as Mexican Vanilla, and Vanilla tahitiensis, commonly called Tahitian Vanilla. The vanilla orchid grows as a vine, readily climbing up and clinging on to trees or any other form of support. On its own, it will grow as high as it can, and produce few flowers. For this reason, growers regularly keep the upper parts of their plants looping down. This stimulates flowering as well as keeping them accessible for harvest. While vanilla is an orchid, it is classified as a spice and is farmed like a fruit. It has about 500 natural compounds, the highest of which is vanillin. Vanillin is also found in many other plants, including tall trees which, when pulped to make paper, release a by-product called lignin from which an artificial form of vanillin is extracted. Any mass-produced food that lists vanilla as an ingredient invariably uses this artificial form, as pure vanilla extract from the vanilla plant is not produced in sufficient quantities to meet world demand and is therefore expensive as well as scarce.
The Vanilla Orchid Plant
Vanilla has both aerial and terrestrial roots. The aerial roots are relatively long and anchor the vine to what supports it (called the tutor). They originate from the nodes in the stems and light grey to tan with greenish tips formed by rapidly dividing cells that easily absorb water. They owe their greenish colour to the chlorophyll they contain, which allows for a certain degree of photosynthesis in these tips. The central core of these roots is surrounded an extra layer of dead cells called the velamen. This acts as a ‘weather jacket,’ protecting the vital tissues of the roots from drought, heat, and excessive sunlight. These roots can grow down into the soil and become terrestrial roots. However, the most common terrestrial root systems originate from nodes in the stems that are buried in the soil. They are identical to the aerial roots, but they lose their green tips and grow horizontally to 30 or more feet (about 10 meters) from the crown in the upper 10 to 12 inches of soil (20 to 25 cm). They are generally much thicker than the aerial roots and are almost always branched. The vines are dark green, fleshy, and high climbing, with a diameter of 5 to 13 mm and internodes 8 to 15 cm long. They will be prostrate and decumbent until they find a tutor, then becoming ascending. The leaves are thick and fleshy, 3 to 8 cm wide by 12 to 20 cm long, with parallel dark striations which become darker when the leaves dry.
The Vanilla Orchid Flower
Flowers are numerous, yellow green, 4 to 6 cm long, borne in short auxiliary racemes. Sepals and petals are typical of most orchid flowers. The yellow lip has what looks like a paw joined to a footless column which bears the reproductive organs. This carries both a male stamen and a female stigma, but it cannot self-pollinate because the anther (that part of the stamen that contains the pollen) and stigma are separated by a membrane called the rostellum. The only way the flower can be naturally pollinated is by the Melipone bee found only in Mexico, which is why that country enjoyed a monopoly on vanilla production for centuries. However this monopoly came to an end with the development of effective hand-pollination methods in the mid 19th century. Vanilla was once $400.00 a kilogram, but it has come down to $35.00 to $40.00 a kilogram due to mass cultivation around the world. Madagascar is the largest producer, followed by Indonesia and then China. Papua-New Guinea is also a significant producer, although it cultivates mainly the Tahitian variety.
Climate, Temperature, and Soil Requirements
Vanilla planifolia grows in 95% of all the growing regions of the world, which in broad terms is any place north or south of the Equator up to about 25 degrees. (It will grow and flower in Brisbane which is 27 degrees but doesn’t like frost of course). In Mexico, vanilla is grown from 50 to 400 metres above sea level. It will thrive satisfactorily at elevations up to 1900 feet (579 metres). At higher elevations the beans will be smaller. Vanilla plants prosper best in tropical areas with a nine-month annual wet season and three-month dry season necessary for the adequate ripening of the capsules. An annual rainfall of 1800 to 2400 millimetres is considered best, with a relative humidity of 70 to 80% and daytime temperatures of 20 to 25 deg C. The minimum temperature should not be less than 4.5º C. Soil for vanilla plantations should have good drainage and with a minimum of 2.5% organic matter and a soil pH ideally tending to neutral, around 6.0. Although vanilla generally prefers a soil texture that is light and loamy, its terrestrial root system is very shallow so it will tolerate a range of soil types.
Propagation
Some horticulturalists have succeeded in propagating vanilla plants from green seed, but the process is difficult, time consuming and costly. If an efficient and effective seed propagation process is ever developed, it has potential as there are about 20,000 seeds in each pod, and being able to germinate even a small percentage of those would be significant. However it is not a viable option at present. As mentioned earlier, tissue culture is an effective available option. This involves taking micro-thin cuttings of actively-growing apical growth. The only disadvantage of this method is that it is slow. Plants propagated by tissue culture take 5 years to flower. The present commercial practice is to re-plant cuttings taken from existing plants. A cutting will produce flowers in about a year-and-a-half. A typical cutting is about one metre long and taken from the newest apical growth. The timing of taking the cutting is important to maintain the productivity of the parent plant. If the cutting is taken at flowering time, it stresses the parent plant and encourages it to keep flowering and re-producing, and it will continue to produce without interruption. However, if the cutting is taken other than at flowering time, the parent plant will not produce in the short term and will take about a year-and-a-half to start flowering again. The main challenge with taking cuttings is prevention of rot. When the vine is cut, it must be allowed to dry. A vanilla vine left on the ground for 6 to 8 weeks will be perfectly OK provided it is in the shade. At Hawaiian Vanilla Co, the practice is to lay the cutting on the medium and place a banana leaf over the lower part of the plant. Tendrils will start coming out from the nodes. When the tendrils hit organic matter, they will take root; when they hit inorganic matter (such as a pole), they will climb. To maximise the growth and vigour of the cutting, as many of the tendrils as possible should have contact with the growing medium.
Farming method
Hawaiian Vanilla Co has tried different styles of growing. In the early days, the crop was grown in five-gallon pots in greenhouses. The pots were placed around galvanised poles in the greenhouses, and the plants were looped up and down the poles and back into the pots to ensure they developed extensive root systems and received plenty of nutrients. The disadvantage of growing in pots was limited air-flow, which is important to vanilla. Further, it came down to economics: an acre of greenhouse is expensive in comparison to an acre of shade house, which is relatively inexpensive. The greenhouses have 2 complete sets of 3 bays. They are open on the sides – with just screening – but have plastic over the top that limits entry of rain water. They are still used at Hawaiian Vanilla Co for starting new plants. New cuttings are planted in pots and nurtured in the green house until sufficiently hardy to be moved to the shade house. Unlike the greenhouses, the shade houses have no plastic on top and are not water-limiting. They have only shade cloth on top that lets in rain water, taking optimum advantage of Hawaii’s 120 inch annual rainfall. They do not limit temperature, rainfall, or humidity; they limit only sunlight, which needs to be limited because vanilla plants do not like direct light. Vanilla needs a lot of shade and a double layer of 62% shade cloth is positioned over the top of the greenhouses and shade houses. Very little light is let through, and the plants ‘relax’ and grow at a steady pace. This is because the green of the plant is very vibrant in deep shade. When new plants are brought in from the greenhouses, no attempt is made to transplant the plants out of the pots because they are susceptible to shock if this is done. The pots with the plants are simply laid in the shade house at the base of poles. The plants readily grow through and around the pots to seek the nutrients in the surrounding medium. Four pots can be placed around each pole. Vanilla likes to be kept moist but not wet. The plants will rot very quickly if too wet. Hawaiian Vanilla Co designed a ‘hanging bed’ growing system that allows water to pass through the growing medium without leaving the plant’s roots sitting in water. This involves placing the growing medium on shade cloth suspended about a foot off the ground on PVC pipes running between galvanised steel poles. The poles are 9½ feet (2.89 metres) apart. The method is inexpensive, and it allows constant air movement through the medium. It also allows the water to pass through while keeping the medium moist. Once a plant gets to a height of about 2 metres, a pole is placed across to another one behind it to enable the plant to follow across and set down roots to find further nutrition. This way the two parts of the plant become separate entities, so if one of them gets diseased or starts to rot, there is another complete loop of plant that can be isolated and used. The plants are looped in this manner as many times as they can go.
What is the growing ‘medium’?
At Hawaiian Vanilla no soil is used as it is most important that the plant’s roots do not become waterlogged during Hawaii’s heavy wet season. Coconut husks form the bulk of the planting medium. The coconut husks are from Sri Lanka and contain salt. This is leached out by repeated soaking of the husks before using them. Larger coconut husks are preferred as smaller ones break down a lot faster. Organic mulch materials are added to the coconut fibre. There is only a metre of mix on either side of each pole, and the hanging beds ensure that water comes in, goes through, and evaporates quickly. This ensures that the plants are kept moist but never wet.
Fertilizer
It needs to be remembered that the natural habitat of the vanilla orchid is in trees: they like to grow up and around trees. It follows that they need more nutrients than a lot of other orchid varieties, which are able to survive in more barren mediums such as gravel, basalt, and pumice. Vanilla orchids need the extra humus that they get from bark and leaves. Hawaiian Vanilla Co adopts organic farming practices and uses fertilizers, pesticides, and fungicides that are certified to be organic. Fertilizer is applied in two ways. The first is by ‘fertigation’ delivering fertilizer in solution through the irrigation system. The fertilizer is an organic ‘crumble’ which is a mixture of various ingredients such as worm castings and fish emulsion. One particular brand of fertilizer granules used lists its ingredients as 2% humic acid, with fish meal, dry composted poultry litter, sulphate of potash, and seaweed. Fertigation is done about once a month, although the frequency is subject to the weather. If there has been a lot of rain, it will be delayed until the growing medium has a chance to dry out a little. The coconut fibre in the growing medium retains a lot of water, and it is not advisable to further wet the roots of the plants to the extent that they might rot. The second method of fertilizer application is by foliar feeding. This is done about every week-and-a-half using organic fish emulsion.
Flowering
Hawaiian Vanilla Co is located north of the Equator, and vanilla gets flowers from January until June. In Hawaii, the plants get light flowers in January and February, very good flowering in March and April, and lesser flowering through May and June. In the southern hemisphere, the opposite is the case: the plant will get flowers from July to December in the tropics with the best flowering in the months of September and October. In SE Qld it is usually November-December. To get vanilla plants to flower, it is necessary to stress them. This is achieved by removing one of the overhead layers of 62% shade cloth described earlier and cutting irrigation. To further stress the plant, 4 to 6 inches is cut off the apical growth of the plant. This has the effect of making the plant ‘think’ it is going to die and it goes into reproducing mode, sending out multiple-flower racemes at every node. This ‘stressing’ is done when the plant is 4 or 5 years old and about the thickness of an index finger, and about two months prior to its flowering peak in March and April. After cutting, it is about 18 months before there is anything saleable, allowing for fruit set, harvesting, and curing. Once the flowers have been pollinated and fruit sets, the layer of 62% shade cloth that was earlier removed is replaced.
Pollination
It is important not to over-pollinate the vanilla flowers, as it will result in reduced crop quality and plant vigour. At Hawaiian Vanilla Co. none of the flowers that appear in January and February are pollinated, nor are the ones appearing in May and June. Pollination is concentrated on the flowers that come on in March and April, when flowering is at its peak. The plants flower during the full moon. Each bloom cluster contains about 20 flowers, of which 6 to 8 are pollinated and the remaining ones cut off. The aim is to concentrate the plant’s energy into those 6 to 8 beans and let them hang. On one vine there should be no more than 75 to 80 beans. By limiting it to this, plant health is maintained and stress is reduced. The pollination procedure is commonly called the ‘marriage of vanilla.’ The pollen of the vanilla orchid is located on the anther. It is not a powder-like substance that is going to blow away. On the contrary, it is about the size of a sesame seed, has a waxy appearance, and looks like a little butterfly. It is not necessary to cross-pollinate with another flower: the pollen is transferred to the stigma of the same flower from which it was taken.
To pollinate the stigma, the pollen mass is removed from the anther using the thumb nail. It is necessary to lift up the membrane (the rostellum) that covers the stigma. The stigma is held with two fingers, and the pollen mass on the thumb nail is placed inside it. The stigma is then tapped gently and closed tight. If the pollination is successful, the flower will wither and a vanilla bean will develop behind it. The flower is small and shallow, so as long as the pollen is inserted sufficiently far in to make contact, the pollination is usually successful. Some growers use devices such as tongue depressors and popsicle sticks to pollinate, but using just the thumb nail is equally effective. A practiced vanilla horticulturalist can pollinate about a thousand plants a day by this method.
Important points about pollination • The vanilla flower opens for just four hours and must be manually pollinated within that time. • The flower opening is at its height about midday.
• If the flower does not get pollinated when it opens, it does not re-flower and the opportunity for pollination is lost.
It follows that there is just a single four-hour window in which to pollinate each vanilla flower. Also, during pollination or any other time, it is best to avoid unnecessary touching of the plant material, as it is very susceptible to viruses and bacteria. The sap of the plant has also been known to cause skin irritation and allergic reactions in some people.
The vanilla pods (or ‘beans’) that develop when hand pollination is successful are three sided, 15 to 30 cm (6 to 12 inches) long, and fleshy. They contain many thousands of extremely small seeds. If allowed to develop to full maturity, they are ‘dehiscent’, that is, they tend to split open and scatter their seeds. This is why vanilla pods must be harvested when they are almost, but not fully, ripe.
Harvesting
Harvesting vanilla beans is almost as labour-intensive as pollination. The beans don’t all develop and ripen at the same pace: each bean ripens at its own time, requiring a daily harvest. The pods are green when harvested and measure at least 6″ (15cm) long. The best commercial size is 10” – 12″ (25cm – 30cm). Each individual pod must be picked by hand just when it is showing signs of splitting on the end. This is usually around ten months after the bean first appeared on the vine. If left on the vine too long, the beans are likely to split open and they will have a reduced market value. At the end of the harvest, the vines are cut off where the beans were. The idea is to create new vines that will be worked up and down the poles, which are no higher than the average person. The vines are encouraged to hang back over and take root in the growing medium below as many times as they can. The ones that are growing back up are the ones that will have the flowers. In the long run the result is a stronger and healthier plant and increased flowering
Treatment of the harvested beans
After they are harvested, the green beans go through a six-month ‘curing’ process where they are graded, soaked in hot water, rolled in cotton cloth to ‘sweat,’ sun-dried on a flat surface to evaporate water, and then stored in a dark room to slowly ferment and produce their unique aroma and flavour.
Grading and Blanching
The beans are graded according to size – large, medium, and small. Each graded batch is then blanched by soaking them for 2 minutes (and no more) in water heated to 160º F. The idea is to rid the beans of any fungi or mould.
Sweating and sun-drying
After blanching, the beans are wrapped in cotton cloth and placed in a sweating box. A cooler is ideal for this purpose because, as well as keeping things cool, it also retains heat longer. The beans are kept in the sweating box for 48 hours and then brought out. The beans no longer look green; they are pale and greyish. They are then laid out in the sun to be dried on a flat surface such as a table covered with black plastic or cloth, in an area where there is just air movement. They remain there until about 3 pm in the afternoon, when they are wrapped up again in cotton cloth and put back in the sweating box overnight. This alternating sweating and sun-drying process continues daily for 3 months. The objective is to remove moisture very slowly until there is only about 23% moisture, similar to that of a prune or a raisin. It is also important to check the beans daily for signs of moulds, fungi, or bacteria. Any beans showing these signs must be removed.
Curing
After 3 months of sweating and drying, the beans are wrapped in wax paper and stored in cardboard boxes in a dark place where there is no air movement. It is also necessary to control humidity so there is not a lot of moisture in the air. The beans remain undisturbed in this dark storage for 3 months, at the end of which they will come out as the final cured product.
The process at Hawaiian Vanilla Co is the one that is described above. Other similar treatment methods are available on the internet. Some of these other methods use ovens to assist in the drying process. For example, one recommends placing the beans on special hand made racks in ovens at a temperature of 68º C (154ºF) for three to four days. At the end of this process (called ‘cooking’), the pods, still in the same wooden racks, must be placed in direct sunshine during 100 full days. The pods undergoing curing must not get wet at any time or they will lose much of their fragrance and commercial value. During the 100-day curing period, if rainy or cloudy days should interfere with this process, the racks and vanilla pods are again placed in the ovens where the temperature is kept between 55º and 60ºC (131º and 140 F) until they can again be placed in the sun.
Further processing into vanilla products
Hawaiian Vanilla Co does no further processing in Hawaii; the cured beans are its final product. The finished beans are sent to the east coast of the USA mainland where they are used to make vanilla extract and other vanilla products.
Pests
In Hawaii, the two main pests have been green caterpillars and spider mites. In an organic context, the caterpillars are picked off and destroyed by hand. Spider mites are controlled by spraying an organic product called ‘Impede’. Where the mite is not widespread, the spray is applied to the apical growth of the affected plant. However, when it is seen to be widespread, it is sprayed more globally. Although these are pests in Hawaii, there is no reason to suppose that similar pests would not be experienced here in Australia. A commonly reported disease is fusarium wilt. Excess water, poor drainage, heavy mulch, and over-pollination create the conditions for development of such fungal and viral diseases. Good plant management practices are the main defence against these.
More information
The website of Hawaiian Vanilla Co contains recipes, general information, and links to various journal articles. The site address is www.hawaiinvanilla.com There is also widely available information about vanilla on the internet. You may access this by simply typing vanilla or vanilla planifolia into the Google search line.
• http://www.orchidsaustralia.com/vanilla.htm • There is an excellent book in the club library titled “Vanilla – Agriculture & Curing Techniques” by Piero Bianchessi of the Venui Vanilla Co. Ltd. Santo, Vanuatu.
• Vanilla (Medicinal and Aromatic Plants – Industrial Profiles) by Eric Odoux and Michel Grisoni
• Vanilla: Travels in Search of the Ice Cream Orchid by Tim Ecott • Vanilla: The Cultural History of the World’s Favorite Flavor and Fragrance by Patricia Rain
www.vanilla.com http://patriciarain.blogspot.com/
• The Vanilla Chef by Patricia Rain • Simply Vanilla: Recipes for Everyday Use by Patty Elsberry and Matt Bolus • The Biography of Vanilla by Julie Karner (teenage book) • July 1989 edition of California Rare Fruit Growers featured an extensive article. • Nov/Dec 2002 edition of California Rare Fruit Growers has another extensive article by David Karp.
• Isabell Shippard wrote an article on Vanilla in Grass Roots magazine.
References:
http://www.sdahldtp.com/vanilla.htm http://www.kafrin.com/bloom/bloom.htm
http://www.orchidsasia.com/vanilla.htm http://www.ippi.com/dir_dat/dat_vanilla.html
http://www.vanillaplantations.com
From the www Ecology: sea-level to 600mtrs high; Climate hot and moist; Insular climate with frequent rain; Rainfall distributed well throughout the year; Two drier months necessary to bring the vines to flower. Without a well defined dry season, there will be no flowers so no vanilla beans. It is better not to plant vanilla in areas where there is no regular yearly production of mango.
Article compiled by Ted Newton
Source URL: https://stfc.org.au/articles/vanilla-by-jim-reddekoff-hawaii-2/
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