| 
  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • You already know Dokkio is an AI-powered assistant to organize & manage your digital files & messages. Very soon, Dokkio will support Outlook as well as One Drive. Check it out today!

View
 

Cassava - kamote 0708

Page history last edited by PBworks 15 years, 10 months ago

 

Cassava - Kamote

 

 

by Trent Ward

 

 


 

 

Description and Rationale

Cassava or manihot esculenta is a root crop that has starchy tubers rich in calories, fibre and vitamin C. Cassava tubers can replace potato and be the key ingredient of many recipes. Also Cassava leaves are rich in vitamins and minerals. The leaves are best boiled in salted water briefly and the water discarded before mixing with other foods. Both leaves and roots can be available year round. Each plant can produce between 5 and 20 kg of tubers. Cassava seems to be widely used throughout the Philippines in farming communities as feed for animals not as much for human consumption. However in rural tribal communities it is used as a backup crop for their rice crops. This is because the rice is not year round and they need something else to supplement for the loss of the rice. Cassava in rural and tribal areas seems to be an untapped resource. Tribal people who have large amounts of land at their disposal could very easily convert it into cassava crops that need no fertilizer apart from ashes turned into the ground. It is a possibility that the unstable rice crop that is difficult and tedious to grow could be replaced by the easy to grow and large quantity of the cassava.

However would only having cassava for a main diet cause health problems from lack of other vitamins and minerals? Or would having large amounts of cassava be able to be used to feed animals as well, resulting in rural tribal people having larger amounts of animals and livestock to consume and sell. This would improve their livelihood and health by the added protein obtained from the meat of animals, which is something that rural and tribal people have little of. However would the planting of large amounts of cassava affect other biological factors in the environment? These factors could include the destruction of natural habitats of native animals because of the clearing of forest to plant the cassava. Also would the clearing of forest cause lack of top soil support because of the loss of deep root trees supporting the soil, causing landslides?

These questions will be answered by literary research, first hand observations and personal interviews with people who may be interested in this research topic. After evaluating the questions and ideas above it is hoped that Cassava may be seen as a major resource and benefit to rural and tribal people of the Philippines. If this is established then it may be possible to educate and show the rural and tribal people the ways in which cassava may benefit their lives.

 

 

 

table of contents...

Biology

 

Common Names and Synonyms

 

Manihot Esculenta’s is also called cassava, manihot, manicot, yuca, cumbahang, kamoteng kahoy (as it is called in the Philippines), tapioca and mandioca. Many different areas have different names for it depending on what area of the world you go to. The common English name is cassava and the common Tagalog name is kamoteng kahoy. 

 

Classification

 

 Kingdom  Plantae – Plants

Subkingdom  Tracheobionta – Vascular plants

Superdivision  Spermatophyta – Seed plants

Division  Magnoliophyta – Flowering plants

Class  Magnoliopsida – Dicotyledons

Subclass  Rosidae - dicotyledons

Order  Euphorbiales -

Family  Euphorbiaceae – Spurge family

Genus  Manihot Mill. – cassava

Species  Manihot esculenta Crantz – cassava

 

 

 

table of contents...

 

Morphology and Physical Description

 

 

 Cassava is a tall semi woody perennial shrub or tree with big palmate compound leaves. It resembles a castor bean plant (Ricinus communis). The dark green leaves are a foot or more across and have 5-9 lobes. The petioles (leaf stems) are very long, up to 24 in (61 cm) long, and they are red as are the stems. Plants can grow to be more than 20 ft (6.1 m) tall in frost-free regions–those of under excellent conditions; however, where they die back and regrow in spring rarely get more than 10 ft (3 m) tall. The tuberous edible roots are 8-30 in (20-76 cm) long and 1-3 in (2.5-7.6 cm) in diameter. They grow in outward pointing clusters from the base of the stem just below the soil surface. Cassava roots must be processed very carefully as they contain glucoside, linimarin, which is acted upon by an enzyme to liberate prussic acid (Hydrocyanic Acid). However this problem is easily solved by the peeling off the purple outer skin which contains the prussic acid and then cooking it. In doing so, the problem is solved. Varieties can be divided into two groups:

o Bitter varieties have roots containing 0.02-0.03% prussic acid. These have to be processed before they can be used as feed.

o Sweet varieties have roots containing less than 0.01% prussic acid. These can be used for feeding without having to be cooked. Most commercial varieties belong to this group (This will be the group used in this project).

 

 

 

table of contents...

 

 

Getting Food

 

 

Cassava is autotrophic: it generates energy through photosynthesis. Photosynthesis is the act in which the plants convert light energy from the sun into chemical energy, which they, then, store in various organic compound—primarily carbohydrates. The energy in the form of carbohydrates is then stored in the tubers and later consumed.

 

Reproduction

 Cassava reproduces through vegetative reproduction. Vegetative reproduction is the process in which roots form on a cut piece of a stem or shoots on a piece of root from the plant. This makes Cassava relatively easy to produce as one only has to cut off a piece and plant it in the ground for it to grow. To propagate cassava, plant the segments of the stem. Cut the stem into 8-14 in (20.3-35.6 cm) lengths, including at least one node, and bury it 3-6 in (7.6-15 cm) deep.

Cassava reproduces with seeds as well. This is what usually happens in the wild. However, producing cassava in this manner significantly decreases the growth rate and is not as beneficial to the harvester.

 

 

Environmental Factors

 

 

Cassava is a typical tropical plant. The approximate boundaries for its cultivation may be accepted as from 30?N to 30?S latitudes; however, most cassavas are located between 20?N and 20?S. In general, the crop requires a warm, humid climate. Temperature is important, as all growth stops when temperature reaches about 10?C. Typically, the crop is grown in areas that are frost-free all year-round. The highest root production can be expected in the tropical lowlands, below 150m altitude, where temperatures average 25-27?C, but some varieties grow at altitudes of up to 1500m.

The plant grows best when rainfall is fairly abundant. However, it can be grown in any region where its annual rainfall is as low as 500 mm or as high as 5,000 mm. The plant can stand prolonged periods of drought in which most other food crops would perish. This makes it valuable in regions where annual rainfall is low or where seasonal distribution is irregular. In tropical climates, the dry season has about the same effect on Cassava as low temperature has on deciduous perennials in other parts of the world: a period of dormancy lasts two to three months. Growth resumes when the rains begin again.

As a tropical crop, cassava is a short-day plant. Experiments conducted in hothouses show that the optimum light period is about 12 hours, and that longer light periods inhibit starch storage.

There are diseases that affect cassava. These include bacterial diseases such as Bacterial blight, Bacterial angular leaf spot, Bacterial stem gall, Bacterial stem rot, and Bacterial wilt. Also, there are fungal diseases that affect cassava as well. These include Anthracnose, Armillaria root rot (shoestring root rot), Black root and stem rot, Blight leaf spot, Brown leaf spot, Cassava ash, Concentric ring leaf spot, Dematophora root rot (Rosellinia root rot), Diplodia root and stem rot, Fusarium root rot, Phytophthora root rot, Pythium root rot, Rigidopurus root rot, Rust, Sclerotium root rot (southern blight) Superelongation, Verticillium root and stem rot, and White leaf spot. Additionally, there are some miscellaneous diseases or disorders that include Post-harvest root rot, Root smallpox disease, and Microbial rotting.

 

table of contents...

 

 

Origin and Distribution

 

Cassava is native to South America however it spread to tropical and subtropical zones throughout the world. Cassava, being easy to grow in tropical climates and able to feed people with little effort, attracted the attention of people from third world countries. To these people, those that were unable to support their own families, Cassava was a life saver. Consequently, it rapidly spread throughout Asia and the indigenous regions of the world.

 

Importance to People

 

 

Cassava is a reliable and important food crop in lowland tropical regions. However, it is low in protein; consequently, in regions where it forms a significant part of the diet, malnutrition is common. Cassava roots contain 25-30% starch. Unfortunately, the plant contains high levels of cyanide in the form of hydrocyanic acid, and this must be removed before the root can be eaten. This can be done by peeling the root, removing the entire purple outer layer, and then boiling it in at least one change of water. Larger roots may have a woody core that can be removed after cooking.

Cassava meal and tapioca are made by grinding the roots in water and then evaporating off the liquid which includes the cyanide compounds. Products made from the cassava root include yuca, tapioca pudding, farinha, starch, soaps, glue, sugar, alcoholic drinks, acetone and cyanide. In tropical Asia the tender young leaves are boiled and eaten. In the Caribbean, juice extracted from cassava roots is flavored with cinnamon, cloves and sugar and is called cassareep; it is used for preserving and flavoring meats.

In addition, cassava can be used for farming communities to feed their animals. These include goats, cows, pigs, and chickens. Although the cassava itself is low in protein, if used to feed animals, it would contribute greatly in supplementing protein in the human diet. The following text explains how this is done.

 

Roots

Both fresh and dried cassava roots are consumed by ruminants in different forms (sliced, chopped, ground). Dried cassava roots have given satisfactory results, as the principal energy source for dairy cattle, intensive beef fattening and lamb growth. Cassava can replace almost all of the grain in the diets with little reduction in performance. Inclusion of levels of up to 65%, preferably pelleted, do not seem to affect their health, carcass quality, or the overall performance when the diets are carefully balanced. Palatability can be enhanced by the addition of molasses (cheap and easily obtainable in the Philippines) if pelleting is not possible.

Complete replacement of grain by cassava root meal in layer feed has yielded similar egg production, despite the significant weight loss of the eggs (a sign of methionine deficiency). Supplementation with methionine has yielded similar results to grain controls. It should be noted that, besides methionine supplementation, careful control of energy-protein ratios is necessary for satisfactory results. The effect of methionine may be attributable to improvement of the protein quality as well as to the utilization of the methionine sulphur in the detoxication process. For unknown reasons cassava meal seems to cause health problems when included in turkey rations.

Leaves

It is possible to obtain from cassava more than 6 tons of crude protein per hectare a year with the proper agronomic practices directed toward foliage harvesting. Cassava leaf and stem meal has been used at the 35% level in cow concentrates to advantage. Cassava bushes can be harvested as forages when they are three to four months old. They are cut about 40 cm from the ground and chopped into small pieces by hand. The forage are used to provide by-pass protein to ruminants fed urea and molasses. The intake of cassava forage is about 5 kg per day, and about two months of adaptation is required before full production can be obtained. In poultry rations, the replacement of as little as 5% of the lucerne meal with cassava leaf meal can significantly reduced broiler weight gains; however, the inclusion of methionine and vegetable oil additives in rations consisting of up to 20% cassava leaf meal practically eliminates the depression in response.

Silage

The whole cassava plant (including root and aerial part) can be chopped and ensiled in simple pit silos for dry-season feeding at the village level. Simple equipment is required both for harvest and preparation of the silage. The silage is fairly well balanced for ruminants.

Cassava pomace (Trester)

Often called cassava meal, pomace is the residue from the extraction of starch from cassava roots. Cassava roots yield approximately equal amounts of starch and pomace, which have less feed value than cassava root meal but can be included in rations for cattle. Starch and pomace are extensively used for pigs in Southeast Asia, where they are regarded as a valuable feed. Up to 10% has been used in poultry rations.

 

 

Survivability and Endangered Status

 

Cassava is by no means endangered. Because it is used as a major food source, people continually produce cassava. Therefore, there is no need to worry about cassava ever becoming endangered. Even though there could be a disease that wipes out a large amount of cassava, it would not matter because it is grown in so many different regions. Not one single disease can completely eliminate the existence of cassava.

The cassava plant is hardy and more capable of tolerating droughts and poor soil conditions than most other food plants. It is also relatively free from pest attack. Cassava can grow in extremely poor, acidic soils because it forms a symbiotic association with soil fungi (mycorrhizae).

 

 

table of contents...

 

 

 

 

Potential Solutions

 

 

Possibility 1

Possibility 1

Can cassava replace rice as the staple food of rural communities? Rice is a tedious and difficult crop to grow as it needs the right conditions all the time and is easily destroyed by the ever changing weather conditions of the tropics. Would it then be easier to exchange rice for cassava as the staple food crop grown?

Advantages

  1. Cassava yields large quantities of tubers per one plant. Having only cassava as a staple crop instead of rice would see a larger amount of food available. Would this not lessen hunger in rural areas?

  2. Cassava is a low maintenance plant. This being so it would require much less energy to obtain food for people in rural areas. This would help with the overall health of the people. The people would not have to over exert themselves which so often happens during planting and harvesting season. 

Disadvantages

  1.  A diet of mainly cassava may not provide the necessary nutrients for people to live healthily.

  2. People may not want to change from their traditional ways of rice harvesting to something new.

 

 

table of contents...

 

Possibility 2

 

 

Can cassava be used as a form of feed for domestic stock?  (Action Step)   

Cassava could be used in place of corn and store bought feeds to feed domestic stock. Because cassava is easy and cheap to grow it could be a possibility to use it to feed the animals of rural people. One way to find out if this would work would be to interview people who own domestic stock. By interviewing people it can be found out which methods of feeding animals are most popular in the Philippines.  Once it is known how people feed their stock then cassava can be adapted to their needs. The man in the picture below owns all the cows in Valley Golf. I interviewed him asking him how and what he fed his cows; he said only grass by moving the cows around the valley every time the grass in one spot diminishes.  The picture of one of his cows below shows that the diet of grass alone seems to leave the cows skinny. This can be seen as the hips and ribs of the cow are clearly visible.

 

 

Advantages 

1. Cassava being used as feed for domestic stock would increase the amount of meat available to rural people giving them a greater amount of protein in their diet.

2. The greater amount of domestic stock available could be sold, giving rural people a source of income to improve their livelihoods.

3. Cassava is cheaper and easier to grow then other forms of feeds leaving people with more resources on hand to be used for other means.

 

Disadvantages

1. People may not want to give food that they themselves could eat to their animals. 

2. Certain animals may not want to eat cassava.

3. It could be possible that certain animal’s quality could be hindered by cassava as it might not be the right kind of food for the animal.

 

POSSIBLE FUTURE DIRECTION

If one of the areas Reggie grazes his cows on could be turned into a cassava plantation the plantation could then be used to feed his cows. This would lessen the amount of movement the cows would have to undertake to get food. With less exercise for the cows they will expend less energy and gain more weight.

 

table of contents...

 

Possibility 3

Can cassava be used as a cash crop giving people in rural communities more money for a better lively hood?

If cassava can be used as feed then people could sell the cassava feed itself and make money off it or people could sell the cassava itself as a source of food.

 

Advantages

1. People with little money and little means to support themselves would have more money to improve their livelihood in many aspects such as buying food, clothes and medicine.

 

Disadvantages

1. Cassava may not sell for enough to make a profit of it.

2. If a lot of people sold cassava the selling price of it would lower maybe making it worthless.

 

table of contents...

 

Bibliography

 

Christman, Steve. "Manihot Esculenta." Foridata. 7 Mar. 05. 11 April 2008 <http://www.floridata.com/ref/M/mani_esc.cfm>.

Carlson, Paul. "Classification." USDA Plant Database. 14 June 2006. 12 April 2008 <http://plants.usda.gov/java/ClassificationServlet?source=profile&symbol=MAES&display=31>.

Lorano, J. C., and B. Nolt. "Diseases of Cassava." Common Names of Plant Diseases. 6 Mar. 1993. APS. 12 April 2008 <http://www.apsnet.org/online/common/names/cassava.asp>.

Mackwin, Paul. "Nature of Cassava." Food Market Exchange.Com. 23 Nov. 2004. 11 April 2008 <http://www.foodmarketexchange.com/datacenter/product/feedstuff/tapioca/detail/dc_pi_ft_tapioca_0202.htm>.

Salvia, De. "CASSAVA: Manihot Esculenta." Agriculture in Sri Lanka. 8 July 1999. 11 Apr. 2008 <http://www.agridept.gov.lk/Techinformations/RTubers/Cassava/cassava.htm>.

Bartlett, Richard, ed. "Uses and Recipes." Cassava. 25 Sept. 1991. 10 Apr. 2008 <http://www.knet.co.za/rbcassava/cassava_uses.htm>.

Gene3.Ciat.Cgiar.Org/Mascas/. International Centre for Tropical Agriculture. C.I.a.T. 4 May 2008 <http://images.google.com.au/imgres?imgurl=http://gene3.ciat.cgiar.org/mascas/mascas.jpg&imgrefurl=http://gene3.ciat.cgiar.org/mascas/&h=546&w=810&sz=81&hl=en&start=32&tbnid=fKKe2swQrZWC_M:&tbnh=97&tbnw=144&prev=/images%3Fq%3Dcassava%2B%26start%3D18%26ndsp%3D18%26hl%3Den%26rlz%3D1T4HPAB_enAU233AU233%26sa%3DN>.

Reggi. Personal interview. 4 May 2008.

 

 

table of contents...

 

 

Comments (0)

You don't have permission to comment on this page.