Gate/GTZ 
Interdev Agroalimentaire  

Market Oriented Yam Storage  Root and Tuber Development Guides (2) 
Reducing Losses and Increasing Income 

	Type de fiche	Techniques/Technologies
	Mise en œuvre	Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH  
 (Allemagne)
	
	Zone géographique	; 
	Mots clés	STOCKAGE; MANIOC; IGNAME

	Public(s) cible(s)	agricultural extension workers, NGOs and others who assist small-scale farmers; policy and decision makers in the field of agriculture 

Problématique / Objectifs
Yams belong to the most important food crops in the West African countries of Nigeria, Côte d'Ivoire, Ghana, Togo, Benin and the Republic of Guinea . Their production account s for about 95% of the world production. Yams are grown in the northern forest and southern savannah zones but are consumed in all parts of these countries. Yams, particularly white yams, are considered a prestigious food and are preferred to other foods by the urban populations. Most yams are marketed as fresh tubers and prepared for consumption within their country of production. Transportation and marketing is carried out by the private sector. 
Description/Mise en oeuvre
Farmers wishing to improve their income all year round must be aware of customer demands, especially those living in urban areas. Good quality and varieties of yam tubers preferred by consumers and possessing good storage qualities should be chosen . The best varieties between regions should be chosen and the advice of the local extension services should be sought on this topic. The following steps are recommended : 

ð Pre-harvest measures 
Use only healthy planting material (tubers or minisets) derived from tubers of medium size and regular shape. Grow yams exclusively on fertile soil that is not contaminated by nematodes, termites or other infestations that may harm the crop. 

ð Careful harvesting, handling and transportation 
Care should be taken that tubers are harvested without squeezing or breaking them. Use appropriate tools for lifting the tubers. Avoid exposure of the yams to strong sunlight for longer period s . Handle tubers gently and never drop them. The best way to transport yams is by placing them into baskets or other containers of appropriate size. 

ð Hygienic Measures 
Choose only healthy and undamaged tubers for storage. They should be of medium size and regular shape. Grade tubers according to their size before storing them so that a uniform quality can be provided at any time. Tubers that are not suitable for storage or will not fetch a good price should be separated from the market tubers before storing. They may be used for home consumption. Clean the storage structure thoroughly before storing and keep it clean at all times. Keep the surroundings clean and clear to discourage rodents. 

ð Construction of the Raised Hut 
.If possible, t he raised hut should be constructed in the village , near the market or close to the road for easy access by truck (see photo page two). 

The raised hut is a storage structure made of locally available materials such as wood, bamboo, straw, etc. Its dimensions may vary according to need . The hut should be at least one meter above the ground. Rat guards should be fixed to the legs to prevent access by rats and mice. The rodent guards consist of metal sheets that are wrapped around all legs and have a length of at least 30cm. Fix the rodent guards with some nails. The store should be protected against theft with a strong padlock. .In some areas, protective measures against termites have to be considered. A simple and cheap method for example is dipping the lower part of the legs that support the hut into wood preventatives or neem oil. 

Inside the raised hut, the yam tubers are best stored on shelves so that they can be inspected easily and rotten tubers should be removed. Large tubers are placed in one, whereas small tubers in two to three layers. Different yam varieties should always be stored separately. 

ð Regular Surveillance 
The tubers should be inspected at least every three weeks. Remove rotten tubers immediately to prevent further contamination. Partially damaged tubers may be chipped and dried or used immediately. Remove sprouts before they have attained a length of 50cm. During long storage, yam tubers loose moisture and shrivel. This minor quality change, however, is unavoidable and accepted by consumers as long as fresh tubers are not available on the market. In dry climates the shrivelling can be reduced by covering the tubers with yam vines, straw or similar material of plant origin. 

Résultats/Eléments chiffrés
contact addresses in the attached document 

Enseignements
Only tubers in good condition should be chosen for storing. Amongst all possible storage constructions the raised hut is the most suitable for the following reasons : 

- it can be cheaply constructed using locally available materials , 

- it provides excellent natural aeration ., 

- it's construction prevents access by rodents , 

- it can be locked against thieves ., 

- it facilitates regular checks ., 

- it can also be used for storing maize, beans and other commodities. 

.In addition, a suitable location of the store reduces the need for handling and permits easier and year round transport (even smaller quantities) to the market. It reduces risks from bushfires and access by farm animals. Regular inspection facilitates sales decisions and improves the farmers position with respect to traders . The improved yam storage system has the following advantages : 

1. Fewer tubers will be lost during storage. 

2. .The number of good quality yams will increase. 

3. The period of storage can be prolonged. 

4. The tubers can be sold at times when the prices are high. 

5. Less tubers will be lost as a result of reduced handling. 

The ultimate result will be a substantial increase in income, as good yam tubers fetch high er prices, especially towards the end of the storage period. A case study in Ghana has shown that the gross margin of yam farmers may increase by over 50% if farmers apply the market oriented yam storage system described . 

Auteur : Carolin Bothe
Saisie le : 17/01/2002
Fiche validée 

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	Contact	Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH  
 , GTZ
Postfach 5180, 62726, Eschborn
Tel.:++49 (0)6196 79-0, Fax: (0)6196 79-1115, E-mail: firstname.lastname@gtz.de
Site web: http://www.gtz.de/

	Références Bibliographiques	Bell, Albert and Henckes, Christian .- Market Oriented Yam Storage - Root and Tuber Development Guides (2) 

Reducing Losses and Increasing Income