Sunday, April 14, 2013

Seed Propagation of Balsam Fir


Seed Propagation of Balsam Fir

Abies balsamea, or balsam fir, is a popular evergreen tree that is native to eastern and central Canada from Newfoundland to central Alberta and the northeastern United States from Maine to Minnesota down to Virginia. Within these areas it may also be known as balsam, Canadian balsam, eastern fir and bracted balsam fir. Balsam firs are part of the family Pinaceae. They are considered a small to medium size evergreen tree because they can grow to be between fourty and eighty feet tall. Balsam firs can live as long as two hundred years. These trees have shallow root systems that hardly ever reach beyond thirty inches deep. They grow best in cooler environments with high soil moisture and a humid atmosphere. 

Balsam fir tree
After twenty to thirty years of growth, balsam firs will produce dark purple cones that stand upright on the upper branches of the tree and release seeds in september. The cones are produced in a single season and are two to three and a half inches long when they reach maturity. The cones produced by balsam firs allows the tree to be distinguished from the fraser fir, which is easily confused with the balsam fir. However, seeds suitable for propagation are produced in intervals only every two to four years. 

Balsam firs are a major food sources for moose and are also a food source for squirrels and many types of birds. Not only are these trees a food sources, but they provide shelter for moose, deer and caribou in the winter months. 

Balsam firs have many uses to humans as well. The resin is used to make Canada Balsam, which was once used as a cold remedy but is now used as a glue in making glass. The wood is used for lumber as well as for making paper. A nontoxic rodent repellent is made from balsam fir oil and the balsam fir needs hold their distinct scent for a long period of time and consequently balsam fir is also used to make air fresheners. But perhaps their most notable use is being a popular choice for Christmas trees. 
The needles of balsam fir are used to for fragrance.
http://commons.wikimedia.org/wiki/File:Abies_balsamea_branch.jpg

Christmas trees have been sold since around 1850. In 2009 the United States sold over 12.9 million Christmas trees. Balsam firs are ranked as the 4th most popular tree for Christmas tree varieties. The top producing states of Christmas trees in 2009 were Oregon, North Carolina, Michigan, Pennsylvania and Wisconsin. 

Propagation by seed is favored for balsam firs. Though they can be propagated by cuttings or grafting and somatic embryogenesis. Balsam fir cuttings are difficult to root. And all three of these methods require a lot of time, labor and money. Since there is a high demand for balsam fir for Christmas trees, it is most economical for them to be started by seed propagation, especially if a high volume of balsam firs is to be produced. Seed propagation of balsam firs is a very simply and easy process, especially for first time propagators or anyone starting a Christmas tree farm.  

The seeds of balsam fir are only viable for about a year, so when you are propagating balsam firs make sure to have fresh seeds. To collect the seeds, you want the seeds to be fully ripe otherwise germination will not occur. You will know when the seeds are mature because the cones will be a dark purple or brown color. Seed fall peaks in September, but starts in August and continues through October. Collect ripe cones and let them dry so you can harvest the seeds from the cones. 
Ripe balsam fir cones

The germination rate for balsam fir seeds is only twenty to fifty precent, but each cone produces over one hundred seeds. The embryo of balsam fir seeds is dormant and thus requires stratification. The seed needs to be planted in moist soil at a temperature of 40 degrees Fahrenheit (4 degrees Celsius) for a one to three month period. This can be achieved by placing the seeds on moist filter paper so that they can slowly take up the water over time, and let them sit in a refrigerator at forty degrees Fahrenheit for a minimum of three weeks. Rather than placing seeds on moist filter paper, alternatively you can place the seeds in moistened perlite for five to ten days, prior to the cold stratification process, for imbibition. You could try planting some seeds outside in the fall and seeing if germination occurs because the cool winter is how the dormancy is broken in nature. However, I recommend placing the seeds in your refrigerator to break the dormancy because this is a controlled environment that you can monitor. 

After the seeds have been stored in cool moist soil for a period of time, you can plant them either in a greenhouse or outside. If you have planted seeds outside to break dormancy, you can dig them up and plant them into containers and keep in a greenhouse. If you plant them outside, it has to be late enough in spring so that there is not threat of a frost occurring. I would recommend planting the seeds and then keeping them in a greenhouse because its an environment that you can control and monitor easily. 
Balsam tree farm

When the tree is big enough to be transplanted outside, which may be in late spring or early summer, plant the tree in the ground and then cover the base of the tree with mulch. Balsam firs are highly intolerant of drought so be sure to monitor the water levels and keep your seedling well moistened. Also, balsam firs are sensitive to light and receive damage for the excessive sunlight easily. Make sure to not let the plant receive too much sunlight, especially when they are in their first year of growth. When you are planting them outside, plant the seedling in an area with at least partial shade, if not full shade.



Sources

Burden, D. 2012. Christmas tree profile. Iowa State University. http://www.agmrc.org/commodities__products/forestry/christmas-tree-profile/ 


Hartmann, H., Kester, D., Davies, F. and R. Geneve. 1999. Plant Propagation. Pearson Education, Inc. Upper Saddle River, NJ. 

McKinley, C. Abies balsamea (L.) Miller. National Christmas Tree Association. North Carolina State University. http://www.realchristmastrees.org/dnn/Education/TreeVarieties/BalsamFir.aspx

Wednesday, March 20, 2013

Grafting Apple Trees


Grafting Apple Trees
Whip Graft 

Apple harvest
Apple trees, or Malus domestica, are deciduous trees and are among the oldest and most widely grown fruit crops in the world. The apple tree originated in Central Asia, and was one of the first tree fruits cultivated. Apple trees can now be found throughout the northern hemisphere. Today there are over 7,000 cultivars of apples. Apples can be used for cooking and making ciders as well as simply eaten. The United States is the second largest producer of apples, making their propagation important in the agricultural industry. 

Apples can be propagated many ways including by seed, layering, cuttings, grafting and micropropagation. The vast majority of domesticated apple trees are grafted. Domesticated apple trees produce seeds that differ from the parent plants, which means domesticated apple trees much be vegetatively propagated, either by grafting or budding.

Grafting is commonly used in apple orchards because it can be done for propagation purposes, creating a new variety or repairing damage. For apple farmers, grafting to certain rootstocks is desirable because certain rootstocks are adapted to distinct environments, are resistant to specific diseases and can decrease the size of the tree, making the tree a more ideal height for harvesting. Another perk of grafting, you will see results more quickly than you would with cuttings and micropropagation. The advantage grafting has over budding is that grafting is done during the apple tree’s dormant months, whereas budding is done during the active growing period which is also a very busy time for farmers. 

Apple Tree

Many farmers graft the variety honey crisp to differing rootstocks. Since their introduction in the 1990’s, honey crisps have quickly become one of the most popular apple cultivars due to their sweet flavor. The high demand of honey crisps along with their higher market price creates an incentive for farmers to graft honey crisp scions to rootstocks of older and less popular varieties.  

Whip graft and machine grafting are the most commonly uses methods of grafting today. A whip graft, also known as a splice graft, is a relatively simple grafting method. Here, I’ll go into detail on how to graft an apple tree using the whip graft. 

Having the correct materials for propagation is essential. Materials needed for grafting an apple tree with a whip graft are rootstock, scion, sharp and sterile knife, budding rubber strips or grafting tape, grafting seal or wax (optional), container and media. 

The first step to grafting success is selecting quality materials for your scion and rootstock. Collect your materials when the apple trees are dormant, which is during the winter months. The materials gathered need to be of current season growth. Branches must be relatively small, no bigger than 1/2 an inch in diameter. The plant used for the scion and the rootstock must be very similar in size for a successful graft. 

Grafting is done during the winter or early spring in a greenhouse environment. If your plant materials are gathered prior to the actual grafting process, make sure to store the materials properly. They should be kept in cool temperatures with moist towels on the cut area to prevent desiccation. I recommend gathering your scion and preparing your rootstock at the same time you wish to complete the grafting. 

How to cut material for whip graft
The scion and root stock are cut with the same angle and length. Look at the figure to the left for a good visual on how the cuttings should look. The angle should be approximately 45 degrees, and the cut will be go through the entire stem. Your rootstock will be planted in a container already, so just be sure water the media well beforehand to prevent unnecessary stress for the plant. You should sterilize your knife before you do the same cut on the variety that you have selected for your scion. The most important part of this stem is to make the cuts clean without burrs and even in angle so that the scion and rootstock will fit together. Once the second cut is made, the next step is securing the scion to the rootstock. 



Making clean cuts with
a sharp and sterile knife








The scion and rootstock are secured together with budding rubber strips, or plastic grafting tape. Make sure that you have the scion placed in the right direction with the apical side upright, otherwise the graft will not be successful. Because tying or taping the union together is an important step, it requires two people. One person is needed as the grafter, or the person who does the cutting and puts the scion in place and a second person is needed as the tier who will finish the graft by tying the union.

It is essential to make the cuts equal and even and secure the scion and rootstock tightly so that the maximum amount of cambial tissue contact is achieved. Without enough cambial tissues layers matching up between the rootstock and scion, the success rate of the graft decreases drastically. You should work rapidly to ensure the plants do not desiccate and cleanly to ensure smooth cuts that seal together nicely and provide close cambial contact. 

Once the union is tied together, a grafting compound such as Doc Farwell’s Grafting Seal or grafting wax may be used for further structural support and to prevent  desiccation. 

Though the whip graft is most often used for grafting scion to rootstock, it can also be used to graft smaller branches onto larger ones. If this is the case, make sure the scion is placed on one side of the rootstock and not in the middles so that the cambial layers match up. 

As for aftercare, keep a close eye on the graft in the first few days proceeding and keep the rootstock well watered so that plant does not become stressed. Make sure to remove the tape as soon as the graft has taken and the scion begins to grow. Failure to do so may result in girdling, which will restrict the growth of the tree. Once the scion has been growing for a few weeks, the plant can be moved from the greenhouse to an outdoor nursery environment to begin hardening off. By early summer the graft should be well established and the tree will be ready to be transplanted in an orchard. 



http://www.geograph.org.uk/photo/227520




Sources 


Crasweller, R. 2005. Grafting and Propagating Fruit Trees. Penn State College of Agricultural Science Cooperative Extensions. http://pubs.cas.psu.edu/freepubs/pdfs/uj255.pdf

Hartmann, H., Kester, D., Davies, F. and R. Geneve. 1999. Plant Propagation. Pearson Education, Inc. Upper Saddle River, NJ. 

Harry Ricker of Ricker Hill Orchards, Turner Maine.

Methods of Grafting. 2009. University of Minnesota Extension. http://www.extension.umn.edu/distribution/horticulture/components/DG0532c.html

Stoltz, L. and J. Strang. Reproducing Fruit Trees by Graftage: Budding and Grafting. Cooperative Extension Service University of Kentucky.http://www.ca.uky.edu/agc/pubs/ho/ho39/ho39.pdf

Thursday, March 14, 2013

Tissue Culture


Propagating Bananas by Tissue Culture 

Banana Plant

Bananas are from the genus Musa and the Musaceae family. Edible bananas originated in the Indo-Malaysian area. Banana plants are perennial herbs, though they are commonly mistaken for trees. Today they are grown in humid tropical places and are the 4th largest fruit crop in the world. 

The main method of propagating bananas is vegetatively with daughter suckers or pups. These contain portions of the roots, corm and rhizome from the mother plant. However, propagating bananas by way of tissue culture is preferred for commercial production and has many benefits. Since the explant used for tissue culture is carefully selected from a strong and high yielding mother plant, the plants will be disease free and high yielding. Banana plants grown from tissue culture also yield earlier than conventionally propagated plants. Tissue culture allows a large number of plants to be propagated in a short period of time, which is helpful for bananas since they are a highly demanded crop. 

Working under a laminar flow hood

Preparing the proper work area is essential. Your work area needs to be sterile and dust free to prevent contamination. If you can work under a laminar flow hood, then do so. However, if you do not have access to a hood then working in a box turned on its side will suffice. As long as you have some sort of cover to prevent dust from falling into work working area then you are good. All surfaces and instruments must be sterilized and cleaned prior to beginning the process. 
Select your explant material from shoot tips from young suckers that are roughly 40-100cm in height. From that sucker, cut a piece that is roughly 1-2cm in length and that includes the apical meristem. The material needs to be sterilized first to prevent unwanted pathogens. First dip the explant into 70% ethanol for 10 seconds with tweezers so that the entire plant is emerged. Then place the plant material in a solution of 2% sodium hypochlorite for 20 minutes. Make sure to time this accurately because too little time won’t do the job and too much time with damage the plant material. The final sterilization step is to dip in sterile water 3 times. 

Growing Medium *Note, this is not
a banana plant*

Using a sterilized sharp knife, cut the plant material into pieces between 5 and 10 mm in size. Carefully place the pieces directly onto the medium. Sterilize your knife frequently throughout this process.The medium most widely used, and which I recommend is Murashige and Skoog medium because it contain all the salts and nutrients needed for your plant. You can place as many pieces of explant on the medium as you please, just make sure its not crowded and that there is space for each explant to grow. 

Once you are done, the petri dishes need to be taped closed, preferably using para-film and place in a growth chamber where you can control the temperature, light and humidity. Optimal temperature for banana tissue cultures are 27-30 degrees Celsius and optimal light cycle is 12-16 hours.

You should check for signs of pathogens and diseases daily. You should discard any plant materials that are showing signs of disease or infection immediately to prevent the contamination from spreading. Banana tissue cultures are susceptible to blackening that results from the oxidation of polyphenolic compounds that occur in the wounded tissues. This causes a barrier to form and prevents the plant tissues from taking up the nutrients essential to its survival.  Because of this threat, the healthy explants should be transferred into new petri dishes every 1-2 weeks for the first 4-6 weeks. Ascorbic acid or citric acid in concentrations ranging from 10-150 mg/l can be added to the medium to reduce the chances of blackening. You can also dip the explant in cysteine 50 mg/l before you transfer it into the growing medium. 

Successfully transplanted banana plant

For rooting hormones, adding IBA and IAA at 2.25 mg/l and 0.175 mg/l respectively to the growing medium is highly recommended. 

Once roots and shoots are established you need to start considering acclimating your banana plants. Start by taking the top off the petri dish for a period of a few days. A minimum period of 10 days is recommended before transplanting. 

When transplanting, carefully remove the plants from the gel and wash all traces of the gel off. This is important because any gel material left on the plant could be a potential source for pathogens. Transplant the plants into plastic pots at least 6 inches in diameter with a potting mix that consists of 2 parts growing media mix, 1 part perlite and 3 parts vermiculite. This will give the plant roots the proper aeration and drainage that it needs. Make sure the soil is thoroughly and uniformly moistened prior to transplanting. The pots should be kept under a misting bench in a green house. The misting system should be closely monitored in the first few weeks after transplanting because the plants will be vulnerable and you don’t want to over water creating a favorable environment for pathogens or under water causing desiccation. 



Sources 

Banana Tissue Culture. S L V Plant Technologies Tvt. Ltd. http://slvplant.com/pdf/BANANA_TISSUE_CULTURE.pdf

Perez, E. and C. Hooks. Preparing Tissue-Cultured Banana Plantlets for Field Planting. Cooperative Extension Service. University of Hawaii at Manoa. https://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/12175/BIO-8.pdf?sequence=1

Hartmann, H., Kester, D., Davies, F. and R. Geneve. 1999. Plant Propagation. Pearson Education, Inc. Upper Saddle River, NJ. 

Morton, J. Banana. Fruits of Warm Climates. http://www.hort.purdue.edu/newcrop/morton/banana.html#Origin%20and%20Distribution  
Strosse, H. Van Den H. and B. Panis. Cell and Tissue Culture, and Mutation Induction. Labratory of Tropical Crop Improvement. http://www.fao.org/docrep/007/ae216e/ae216e03.htm 

Thursday, February 14, 2013

Propagating Holly by Cuttings


Propagating Holly by Cuttings  



Background

Holly is a beautiful plant that is often ossociated with Christmas

Ilex, also knows as Holly, is a evergreen and deciduous plant found as shrubs, trees and climbers. Holly is found throughout the United States. The female plants produce red berries that are commonly used for decorative purposes, while the male plants are only used for pollination. A female plant will only produce the red berries once they have pollinated. When holly is propagated by seed, the sex of the plant cannot be determined until the seedling start blooming which can take between 4 and 12 years. Holly can be propagated in a variety of ways including by seeds, cuttings and grafting. However, Given the desirability of holly bearing red berries, propagating by cutting is the most commonly used method so that holly can be produced on a large scale. Here, I'll go into detail on how to propagate with cuttings.

Selecting and Preparing your Media


Potting mix is best for planting your cuttings because of the aeration,
 drainage and nutrients it contains.



Firstly, you want the proper media prepared for planting your cuttings in. You will want a soil medium with the proper soil components for aeration, drainage and water and nutrient holding capacities for the best propagation results. Field soil will not be as suitable as a potting mix at fulfilling those needs. If you stop by your local hardware store or Home Depot, they will have different varieties of potting mix for you to choose from. Any of these varieties will work well for your cuttings. Fill a tray with potting mix and then water the tray well. You want the medium to have plenty of moisture for the cuttings to be able to take up, but be careful to not over water. If the medium become too water-logged then the reduced levels of oxygen in the soil will make it difficult for the vulnerable cuttings to establish roots and survive.

Selecting and Gathering Propagation Material
Next, you want to collect your cuttings. Selecting the proper material for cuttings is essential. You want to select cuttings of semi-hardwood tips from current season's growth. The parent plant should be well matured. The timing of collecting cuttings is essential. For optimal rooting, gather your cuttings in mid to late summer, although cuttings may be collected into the following spring as well. 
A sharp and sterilized knife or pruning sheers is essential for collecting cuttings
When cutting material for propagating, be sure to have a sharp knife or pruners that have been sterilized to ensure no pathogens are being spread when you are cutting. You should also wash your hands just prior to taking the cuttings. I would suggest taking the cuttings in the early morning hours when the plant is well hydrated and turgid. Each cutting should be at least 6 inches long and cut right below a bud. You should keep the cuttings in a glass of water or wrap a moist towel around the bases to avoid desiccation until you are ready to plant them. 

Planting your Cuttings
Wounding your cutting at the base will promote rooting

Remove all leaves on the bottom 1 inch of each cutting. Wounding the cuttings at the base by stripping off the outside layer of bark with a sharp knife will help induce rooting. However, wounding your cuttings is not a necessary step.  

The use of Auxins will greatly benefit your cuttings. Plant hormones can be purchased at your local garden store. Generally, IBA in concentrations 8,000 to 10,000 ppm will work for most cultivars. However, the concentration of auxins depends on the cultivar that you are propagating so I recommend doing research on your specific holly variety before purchasing the rooting hormones. Dip the bottom 2-3 inches of the cuttings in a powder formulation of IBA, making sure the IBA is uniformly spread, prior to planting. 

Place all cuttings deep enough in the soil for the cuttings to stay upright, which would be approximately one to two inches deep. Pinching the soil around the base of the cuttings would help for stability. 

Post-planting Care
Once the cuttings have been planted, they should be kept in a warm environment, usually between 21 and 26 degrees Celsius and misted regularly. Wrapping the tray with a type of plastic will help maintain a warmer temperature and moist environment in the soil. Watch for fallen and dead leaves and remove them immediately to avoid unwanted pathogens. If you have the supplies and capability, bottom heating the tray will be very helpful for allowing the plants to establish roots. Once strong roots have formed and visible signs of growth are evident, then the cuttings can be transplanted into individual pots. Visible signs of growth will be bud formation/swelling and new leaves forming. This should happen after 4-6 weeks. 


Enjoy!
http://farm3.staticflickr.com/2212/2051398920_1bcc904c0c.jpg




Sources



Braley, H. How to Root Holly Cuttings. http://www.ehow.co.uk/how_7551155_root-holly-cuttings.html. 


Hartmann, H., Kester, D., Davies, F. and R. Geneve. 1999. Plant Propagation. Pearson Education, Inc. Upper Saddle River, NJ. 

Khan, T. How to Propagate Holly From Cuttings. http://www.ehow.co.uk/how_8284354_propagate-holly-cuttings.html

Rhoades, H. Propagation of Holly Shrubs with Holly Cuttings. http://www.gardeningknowhow.com/ornamental/shrubs/holly/holly-cuttings.htm