Sawdust prolongs the storage life of potatoes

Post-harvest activities

Notes to broadcasters

Save and edit this resource as a Word document.

The potato plays an important role in the food security and livelihoods of farming communities in many developing countries. According to the Food and Agriculture Organization of the United Nations (FAO), the production and consumption of potatoes is steadily rising. Developing countries now account for more than half of global potato production.

Storage presents a big challenge to farmers. Potato farmers harvest their whole crop at the same time. This floods the market and means that farmers receive low prices for their produce. Potatoes are spoiled if left for long in the field when ready for harvest. They are attacked by pests and do not last long during storage. This leads to great losses for farmers.

Such harvest losses have serious impacts on food security and farmers’ incomes. They also contribute to high prices for consumers when the crop is out of season.

This script looks at a creative approach to the problem of potato storage. The farmer uses sawdust to preserve his potatoes for a longer period. The story highlights local innovations that farmers are discovering to address the challenges they face on the farm.

The script is based on actual interviews. You could use this script as inspiration to research and write a script on a similar topic in your area. Or you might choose to produce this script on your station, using voice actors to represent the speakers. If so, please make sure to tell your audience at the beginning of the program that the voices are those of actors, not the original people involved in the interviews.

Script

Signature tune: Up for 5 seconds then down and out under presenter

PRESENTER:
The potato is an important food crop in Kenya. It is grown in the highlands of Central, Rift Valley and Western provinces. However, the production and marketing of potatoes is hampered by poor storage conditions that dent farmers’ income and morale.

In today’s program, we meet a potato farmer who has discovered a wonderful way to keep his potatoes in good condition for a longer time after harvesting.

SFX:
Sounds of a market place. Fade under the presenter.

PRESENTER:
This is Kinungi Trading Centre on the busy Nakuru-Naivasha highway. It is early morning and the local market is bustling with activity. Today, farmers have few potatoes to sell. The last harvest was three months ago. The new crop is still growing.

But that is not the case for Mr. Githenya Kariuki. He is here to sell his potatoes to a buyer from Nairobi, 70 kilometres away. He says his potatoes are now in season, thanks to his new method of storing potatoes using sawdust.

GITHENYA:
You see, I rely on potatoes to take care of my family. I feed and take my children to school, and I have some income left to deal with hard times. I have three kids in secondary school and that is not a joke. School fees are a lot of money for somebody like me who relies entirely on farming.
SFX:
Sound of people walking and talking. Bring up and cross-fade under the presenter with the sound of someone tilling land.
PRESENTER:
We walk three hundred metres off the main road and arrive at Githenya’s farm. Mrs. Githenya is ploughing a section of land that her husband says will be planted with potatoes.
SFX:
Sound of door opening
GITHENYA:
This is my store where I keep most of my produce.

INTERVIEWER:
The store is big! You must have used a lot of wood to construct it. I can see what looks like a heap of grass in that corner. Is it feed for your cows?

GITHENYA:
I use it eventually to feed the animals. But this grass prevents the sawdust from being blown by strong winds in the early morning. If that happened, my potatoes would be exposed to light and it wouldn’t be long before they started changing colour. When they start to change colour, they are no longer good for human consumption.
INTERVIEWER:
Has that been a problem for you in the past?
GITHENYA:
I have always wanted to keep potatoes for longer. Usually, I kept them in a corner of my store. But after a while they turned green and were no longer good for sale. So I was forced to sell everything immediately after harvest. Because there are so many potatoes on the market after harvest, prices are low. When the potatoes spoil, I can use them for seed, but I cannot use everything that goes bad for seed. It would be too much of a loss for me. I wouldn’t recover the money I invested for ploughing, seed, fertilizers and labour.
INTERVIEWER:
So, how did you discover sawdust?
GITHENYA:
I use sawdust as bedding for my chickens. One day, I went to the dumpsite where carpenters dispose of wood shavings. As I was picking up the sawdust to take with me, I came across potatoes that had been thrown away. They looked like they were still in good condition. This gave me the idea to use sawdust instead of the grass I had been using to cover my potatoes. I used alternate layers of sawdust and potatoes, starting and finishing with a layer of sawdust.
PRESENTER:
A potato is just like any other living organism. It lives and breathes. If you keep it in a warm place, it will grow. If you seal it in a plastic bag, it will suffocate. If it is diseased, it will spoil. Let’s get back to the interview with Mr. Githenya.

INTERVIEWER:
What did you learn in the course of this experiment?

GITHENYA:
One thing I learned is that the sawdust must be moist but not too wet. If the sawdust is too dry, then the quality of the potatoes will decline very fast because they will dry out and be attacked by insect pests. On the other hand, if the sawdust is too wet, then the potatoes will get rotten after a short time.
SFX:
Sound of grass being turned and shoved aside

INTERVIEWER:
How many kilograms of potatoes are in this heap?

GITHENYA:
This heap has 400 kilograms. This other heap has 300 kilograms. I arranged them in such a way that I maximize on space. Remember this is a store and I have other things to keep here as well.

INTERVIEWER:
What challenges did you face while trying out this method?

GITHENYA:
(Laughter) Sometimes people do not believe something until they see it working. When I told my wife about trying out an alternative method of storage, she complained that it would take up too much space in the store. I told her that we could try it once and if it didn’t work, then we could leave it alone. So she accepted.

But I had another problem. At first, the carpenters gave me sawdust for free. But after a while they asked me to pay for it. I didn’t have that much money. So we reached an agreement that they give me the sawdust in exchange for potatoes of the same value.Â

PRESENTER:
Githenya did not stop there. He shared the success of the new method with farmers in his group.

GITHENYA:
When other farmers tried out this method, they said that their potatoes stayed healthy for longer than with other storage methods. That is why for the last three years, members of my farming group have used the sawdust method. Using sawdust is so efficient that now we can store our potatoes for up to four months after harvest.

PRESENTER:
Mr. Samuel Njiru is the District Agricultural Officer in Kinangop District. He says that poor harvesting practices can lead to huge losses during storage of potatoes.

MR. NJIRU:
Good storage starts at harvest. The timing of harvest is a delicate balance. Farmers must be very careful not to harvest too soon or too late. Some of the infections that attack potatoes during storage begin during harvesting. To avoid this, potatoes should be harvested only when the tubers are fully mature. This reduces the bruising of the skin that can lead to infections. On the other hand, if potatoes are harvested too late, they are more likely to already be infected.

INTERVIEWER:
How do you reduce the bruising of tubers?

MR. NJIRU:
To avoid damage, it is good to cut the tops 10 days before harvesting the potatoes. This gives the potatoes time to develop matured and hardened skins. Farmers should also make sure that they don’t harvest when it is raining. If this happens, allow the tubers to dry in heaps for about 10 days, in a cool place.

PRESENTER:
Thank you, Mr. Njiru. Let’s summarize the main points for our listeners: First, harvest potatoes when the skins are hardened but not too late. Second, pick tubers with no signs of damage. Third, use alternate layers of sawdust and potatoes in storage. And finally, select and dispose of any tubers that are spoiled.

SFX:
Sound of a three-wheel motorcycle, getting louder and softer under presenter

PRESENTER:
I leave Kinungi as Githenya loads his last batch of potatoes onto a motorcycle with a trailer. He makes one more journey to the market, thanks to his new method of using sawdust to store his potatoes for a longer time.

SFX:
Sound of a three-wheel motorcycle, getting louder and softer under presenter

PRESENTER:
If you have any questions on today’s subject or any other concerns on your farm, send them via SMS to 0715 916 136. The Organic Farmer will respond by text, phone call or by post. Until next week same time, my name is ………. wishing you a blessed night.

Ending tune, up for 4 seconds and fade out.

Acknowledgements

  • Contributed by: John Cheburet, The Organic Farmer, Nairobi.Â
  • Reviewed by: Dr. Victor Mares, production systems agronomist and post-harvest expert, the International Potato Center (CIP).

Special thanks to the Commonwealth of Learning (COL), the United Nations Educational, Scientific and Cultural Organization (UNESCO), the Food and Agriculture Organization of the United Nations (FAO), the Government of Canada through the Canadian International Development Agency (CIDA), the Donner Canadian Foundation, the World Association of Community Radio Broadcasters (AMARC), Inter Press Service (IPS) Africa, and the Technical Centre for Agricultural and Rural Cooperation (CTA), for supporting the radio scriptwriting competition on smallholder farmer innovation.

Information sources