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

  • Dokkio Sidebar (from the makers of PBworks) is a Chrome extension that eliminates the need for endless browser tabs. You can search all your online stuff without any extra effort. And Sidebar was #1 on Product Hunt! Check out what people are saying by clicking here.


Mt pinatubo eruption’s impact on local environment 0809

Page history last edited by ecop 13 years, 2 months ago

The Sweet Potato: Mt. Pinatubo Regions Savior?



“Poor man’s food” or crop of the future?


By: Matt Thiessen 




Description and Rationale



In June 1991, the second largest volcanic eruption of the last century took place on the island of Luzon in the Philippines, just 90 kilometers northwest of the capital city Manila. Many people were killed and over 100,000 became homeless following the Mount Pinatubo eruption, which practically exploded and devastated the immediate surrounding region on June 15, 1991.  Millions of tons of sulfur dioxide were discharged into the atmosphere, resulting in a decrease in the temperature worldwide over the next few years.


Immediately following the eruption, the ash from the eruption or “lahar”, mixed with rain caused massive flooding as it flowed in torrents downstream wiping out much of the land, which was once fertile farmland to the indigenous Filipinos of that region.  The main staple crops that were once grown there before the eruption were sugarcane and rice.  As of now, much of the rich, fertile soil has been washed away due to flooding following the eruption.  As a result the soil, has become drastically less unsuitable as the topsoil mainly consists of the lahar ejected from Mt. Pinatubo.  Since many Filipinos now live in that region again, they have resumed their old lifestyles of farming, but with less success and as result, a loss of income for their families. 



The purpose of this project is to see if there is a way to improve the methods of farming or find a better growing crop than rice because of the difficulties in the unfertile soil.  If a fertilizer were made that worked in the soil of the lahar to provide more nutrients that would coexist with the elements of the lahar.  Another factor would be, “is there any alternate crops that tend to grow better in the volcanic ash?”  If such a plant is able to grow it would greatly increase the incomes of Filipino families who were devastated by the eruption.  The standard of living would go up as a result of this. 


I will research what kinds of elements are compounded to make up the lahar.  Research will also be done to find out what kind of wildlife is and was native to that region, and has there been any disappearance or minimal amount of certain species.  I will then try to interview local farmers of the lahar region to get details on the actual effects to the environment because of the devastation caused by the Pinatubo eruption.  Interviewing agricultural experts will also be helpful in receiving an opinion of what methods are best in farming and what will help the agricultural growth for the sugarcane and rice plantations.  I hope to be able to assist the people of the region in providing them with a better income through more efficient farming techniques that need to be altered because of the obstacle of the inefficient soil. 




main table of contents...



Common Names and Synonyms


To local farmers in the Philippines, it is know as “kamote”, which is the direct translation of sweet potato.  This plant is a widely cultivated crop throughout the world, as they grow underground and have nutritious tubers.  Ipomea batatas is the scientific name for the sweet potato plant.  Other synonyms include “Uala, uwala” (Hawaii), “Süsskartoffel” (Germany), “Kumala” (Tonga, Polynesia), ‘Umala (Samoa), and “Kumar” (South America).






Kingdom: Plantae (plants)

Phylum: Magnoliophyta (flowering plants)

Class: Magnoliopsida (dicotyledons)

Order: Solanales (flowering plants)

Family: Convolvulaceae (morning-glory)

Genus: Ipomoea (annual/perennial herbaceous plants)

Species: Ipomoea batatas (sweet potato)


The sweet potato is often confused with other similar cultivated plants such as yams (in the Dioscoreaceae family), cassava or  the regular potato (Solanum tuberosum).  These are all used in the same edible manner.


main table of contents...


Morphology and Physical Description




The vine has rather heart-shaped and palamately lobed leaves and purple flowers.  Flowers are about 5 cm in length.  They are  self-sterile (which means they need pollination to occur even though they contain both sex organisms) and have a fairly  funnel-shaped appearance.  The edible root is long and conical with a smooth skin of varying colors from red, purple, brown and  white. The flesh varies from white, orange, purple and yellow (www.stuartxchange.com).  There are five different stamens that attach  themselves with cilia-like hairs to the corolla.  Sweet potatoes are dicotyledons (having two embryonic seed leaves).       


Sweet potatoes are generally very healthy to the body as nutrition.  The potato contains 20.1 grams carbohydrates, 12.7 grams  starch, 4.2 grams sugar, 0.1 grams fat and 1.6 grams of protein.  Sweet potatoes are also a good source of vitamins.  They contain  709 μg vitamin A, 17.06 mg vitamin C, 0.52 mg manganese, 0.26 mg copper, 3.14 dietary fiber, 0.25 vitamin B6, 306.05 mg  potassium and 1.46 mg of iron.  They are very abundant in nutrition.



  The absence of light and temperature underground and moisture conditions influence tuberization of the actual growth of the roots  into new potatoes. When tubers are formed the needed nutrients are produced more readily because of  less of a need to depend  on the plant organisms to produce the necessary nutrients for the potato.  Generally, sweet potatoes are a crop that does not need  as much water as most cultivated plants do.  Therefore, they are able to survive better in harsh conditions with miniscule amounts of  water.

                                                                                                   main table of contents...

Getting Food


Sweet potatoes are very similar or almost identical to any other plant in their food processing. Ipomoea batatas or the sweet potato is an autotroph. This means it is an organism that produces complex organic compounds from simple inorganic molecules using energy from light (photosynthetic). In other words, it mostly gets its food source from light. Sweet potatoes also absorb water through their tubers and store it. The best fertilizer for them is the waste from animals, which have lots of nutrition.  Potato roots get nutritious food such as bacteria animal wastes from soil and search water.  Light and temperature are the two key factors in the growth of a healthy and productive sweet potato.  Sweet potatoes are good sources of vitamin C and E and many other vital nutrients for the body.



main table of contents...




Sweet potatoes reproduce asexually, meaning that the process of mitosis makes “clones” of the original parent plant.  Generally, the vegetative part of the potato takes credit for most of the reproduction, and thus termed vegetative reproduction.  Plants have annual organs that store reserve nutrients that can supply a plant during a period of adverse conditions.  In sweet potatoes, these organs are contained in root tubers, which is where the reproduction occurs.  After the tuber is fully matured, it dies out and the reseeding is started from within the tuber.  Tuber initiation is 50-60 days.  Depending on conditions, tuber roots will mature within two to nine months.  For the most part, sweet potato plants do not die if left alone, because they are vines that creep along the ground.   

main table of contents...


Environmental Factors


Ipomoea batatas grows best in warmer climates with an average temperature of 24 °C and plenty of sunshine.  The sweet potato thrives considerably with an annual rainfall of 750-1000 mm of rain, but can still produce a good crop with as little as 500 mm.  When the tuber of the potato plant is being initiated, around 50-60 days, it is vital that intense flooding or a severe lack of water does not damage the tuber.  Maximum growing conditions are around 85-90% capacity growth in 3 to 16 °C temperatures, a pH of 4.5-7.0 in the soil and a lack of aluminum toxicity in the soil.  These potatoes can grow in almost any type of soil with little or no fertilizer and still flourish noticeably.Sweet potatoes are susceptible to a variety of fungal, bacterial, parasitic and viral diseases, which will kill or at least decrease the efficiency of the plants’ production.


main table of contents...


Origin and Distribution




origin of sweet potatoes is South America around the Peru, Venezuela area of
the continent. Records seem to show
signs of Ipomoea batatas existing there around 5,000 years ago. From South America, it spread to the
Caribbean as well as Polynesia, where it apparently was grown soon after that
time. It is hypothesized that the
origin point of the sweet potatoes was between the Yucatán Peninsula of Mexico
and the mouth of the Orinoco River in Venezuela (www.wikipedia.com).
         China was another country to soon incorporate sweet potatoes as one of their staple crops.  Today, China supplies the world with about 80% of consumed sweet potatoes.  From China, it spread throughout Southeast Asia, which included the Philippines, Taiwan, Japan, Indonesia and India.  Sweet potatoes are also an important crop in Africa.  It was thought that the potato influence came through Europe from early explorers and missionaries. 

main table of contents...


Importance to People


 main table of contents...


Survivability and Endangered Status


Sweet potatoes, or Ipomoea batatas can basically survive in most climates throughout the world.  It cannot survive very well in cold weather than 0°C.  So thus it is more limited to southern countries of Asia and South America but is able to grow in Europe and North America, but not as abundantly.  It also can survive with very little soil and water, which makes it an economical cultivar.  Generally, sweet potatoes do grow outside of cultivation.  They are easy to maintain because they have little or no predators.  The potatoes are toxic if not prepared right before being consumed.  For the most, Ipomoea batatas is not even close to being endangered as it is grown worldwide, so there is no fear of it becoming extinct.



main table of contents...


Potential Solutions


Could the sweet potato be a key factor in changing the lifestyles of the Filipino farmers in the province of Pampanga, Philippines?  After many hours of research, it appears that the sweet potato is an ideal crop to grow for people living in the area that was ravaged by the volcanic ash (lahar).  The sweet potato grows extremely well in the lahar and needs little attention from a farmer until the harvest season.  It needs little water, so therefore requires little to no irrigation and the rainy season can be relied on to irrigate the crop.  Sweet potatoes are also a good, if not better nutritional alternative than rice, the latter of which is the staple crop and main food of consumption in the Philippines.  The main thing that has hindered the “kamote” (sweet potato) industry is that people seem to think that the crop does not market well. However, that is really only because they maintain the tradition of eating and marketing rice.  Thus, they are not really motivated to change their lifestyle.  If Filipinos would be willing to look past tradition and see the true nutritional value in the sweet potato, perhaps they would be more interested in producing it as a crop for marketing.  As a result, the percentage of poverty in the Philippines could decrease, as more people would consider this their livelihood.






An article posted on GMANEWS.TV, April 29, 2008 stated how President Gloria Macapagal Arroyo was urging people throughout the Philippines to resort to growing “kamote” (sweet potato) as an alternative or an addition to growing the traditional rice.  The kamote industry, if made a larger factor in the lifestyle of the Filipinos, would benefit them greatly if more kamote was grown by the local people and adopted into their daily diet.  One solution would be if the Philippine government were to select farmers, especially from the lahar-devastated regions and provide funds to plant kamote as a main crop and set an example for other farmers to do likewise.  This could likely change rice from being the sole staple crop, as well as help lowlanders and also Ayta people living near Mt. Pinatubo receive a better income. 




  1. Filipino lifestyles in the Pampanga area (lahar-devastated by Mt. Pinatubo) or anywhere would be drastically improved by planting a cash crop of kamote.  It would save them from having to buy things at the market that they could grow in their backyard in the lahar soil. 
  2. An extra cash crop would provide them with more of an income to afford necessities essential to their lifestyle. 
  3. Kamote is a root crop that has adapted well to the volcanic ash and its growth is easy to maintain.  Thus, it would not really be any sacrifice for farmers to grow the sweet potato because it costs very little to plant. 
  4. Farmers could harvest multiple kamote crops per year rather than being reduced to harvesting only one crop of rice annually in the lahar, which is unsuitable to grow rice.  Even though rice may be more expensive in the markets, having three or more crops of kamote would make a lot more money than just one crop of rice per year.




  1. The Philippine government does not often work quickly.  They have great ideas but often follow through with their plans.  It would take a lot of cooperation between the government and the Filipino farmer for this to happen.
  2. Filipinos naturally will only try things if they see that it already works or that someone else was successful.  So it would take a lot of effort to prove to everyone that sweet potato could be the most productive crop grown in lahar. 

       3. For people like the Aytas, they would be able to grow the kamote easily. But living so far away from urban areas makes it a problem to transport and market their                 produce.  The government cannot really help with that problem if the sweet potato industry is not yet a significant marketing product.



main table of contents...



Possibility 2 - PRODUCTS OF “KAMOTE”



In addition to the consumption of the sweet potato, other products can be produced from this crop.  Ordinary ingredients such as flour, molasses, sugar, starch and yeast can be made from the sweet potato. Other products are feed for animals, medicinal uses, dyes and paints.




  1. Filipinos could save on their expenses by extracting these ingredients from the kamote instead of buying the same ingredients from the market.  Kamote also has more nutrients than rice.
  2. People will be healthier by eating food that contains kamote products.  Artificial ingredients have fewer nutrients than natural products.
  3. By making other products from the sweet potato, Filipinos can sell these products as well to have another source of income for their livelihood.




  1. It is difficult for Filipinos to catch on to an idea unless they see it work and become successful for someone else first.
  2. People will not take their own initiative and try new things because they are so locked into tradition and how things have always been done.  They would rather hold on to tradition rather than change their livelihood even after a natural disaster occurs.

       3.     People selling products made from the kamote might not get a lot business because many are already used to buying the            artificial ingredients of what they have                always used.  Therefore, they do not see the nutritional value in organic products from the           sweet potato.



main table of contents...





Bautista, Cynthia Banzon. (1999, June 10). The Mount Pinatubo Disaster and the People of Central Luzon. Retrieved March 12, 2009.




ECHO staff. (1992, April). Gardening in Volcanic Ash. Retrieved March 11, 2009.




Gloria Macapagal Arroyo: GMA News interview. (2008, April 29). GMA News.TV (Manila, Philippines), 1, 1.




Gocon, Mr. Manny and Mrs. Linda. Personal Interview. 1 May 2009.


Green, Mr. Roger and Mrs. Joanne. Personal Interview. 22 April 2009.


McCormack, Gerald. (2007). Cook Islands Biodiversity Database. Version 2007.2. Cook Islands Natural Heritage Trust. Rarotonga. Online at




Nikdau, Mr. Dominador. Personal Interview. 1 May 2009.


PAN Germany. (2009, January 13). Sweet Potato. Retrieved March 12, 2009.




Philippine Medicinal Plants. (2009). Kamote/Ipomoea batatas/Sweet Potato. Retrieved March 12, 2009.




“Root Crop Behavior in Volcanic Ash.” Radix. Vol. XIII. No 2. (1991) 8-9.


The Sunday Times. (2008, March 16). Fusion kamote. Retrieved May 2, 2009.





main table of contents...


Comments (0)

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