Summary of the report to GTZ in 1998
Technology transfer of post harvest solar drying techniques
1.0 INTRODUCTION:
In 1998, FADECO received financial support from ISAT/GATE/GTZ
Small scale fund (12.000 DM) for the transfer of the solar drying technology
in 10 villages of Karagwe district. FADECO is presenting here some highlights
from the report that was prepared and presented to GTZ upon successful
implementation of the project.
2.0 Brief history of the project:
Karagwe district is among the most fertile districts in
the whole of Kagera region with a very high agricultural potential. The
district receives adequate rainfall and has very favourable weather permitting
two seasons of crop growing. The lack of adequate access to market opportunities
is one of the biggest constraints facing agricultural development in the
district. This market problem brings about other related crop husbandry
problems including the storage and preservation.
2.1 Status qou::
2.11 Lack of post harvest mechanisms in Place:
Throughout the district, there are no existing coping post harvest systems
in place. Food is from garden to pot to mouth. Beans and maize have a
temporary storage system which is primitive and lead to loss and wastage
to pests and rodents. Cereals and root crops are grown on a small scale,
and so do not pose much problems for storage. It is most probable that
if post harvest techniques existed for most of the crops potentially grown,
the over all crop production and food availability would much higher.
Because of this lack, farmers grow just enough to eat and finish.
2.12 Food wastage and Loss:
Although there is abundant crop production, very little is consumed locally
and still a much smaller volume has a market outlet . Crops such as fruits
and vegetables are lost especially at peak season.
2.13 Production levels and potentials:
Karagwe district has the potential to produce enough food to feed other
parts of the country. However limited access to markets has greatly influenced
the production capacity. Land which would be a major factor is not a problem.
Farmers have unlimited access to land.
As a result, production levels are lower than can actually be produced.
Most farmers have not got the expected motivation to increase their production.
Why should after all one produce crops that will not be consumed all or
sold to get income. So farmers just produce enough to eat and a little
surplus for their own needs.
2.2 Factors leading to poor accessibility of the market:
2.21 Poor road and communication infrastructure:
The district has had a very poor network of feeder roads. This meant
that, farmers can not transport their crops to the main roads. Secondly,
communication between villages is very difficult since one has either
to cross several valleys over small and temporary bridges. Movement by
lorry to collect crops from villages is very difficult and impossible
in most areas. Transportation is either by bicycles or on head.
Roads connecting the district to other areas like Bukoba, Mwanza, Kigoma
are seasonal which are most often in worse situation. Transportation by
Lorries therefore becomes very expensive. The marine connection from Bukoba
to Mwanza was closed after the MV Bukoba capsized with over 800 people
on board. The main cause was over-loading with bananas from Kagera to
Mwanza.
2.3 Food security in the context of Karagwe District
The project has had a preferential focus on the food insecure as a focal
target group. During this phase of GTZ funding, some time has been taken
to explain what food insecurity means in the context of Karagwe. Food
security has been broadened to refer also to livelihood security because
access to food is equally defined by the extent to which the basic household
needs can be satisfied.
2.31 Diagnosis and analysis of food security situation in Karagwe district
It has been seen important and necessary to make an in-depth diagnosis
of food security problems in the district in relation to the socio economic
situations. Only then will the causes of food security be thoroughly tackled
and the functioning of the project be rendered efficient and profitable
in the long run.
2.32 The food security situation in Karagwe district can be defined
into two zones:
Zone 1
This is the area in the north of the district with low food / cash crop
production levels. The food security problems are therefore manifested
in low crop yields, with pronounced food shortage in most months of the
year. Mostly parts of Bugene-Nyaishozi division.
The main results of this food insecurity is therefore in the form of
low incomes because the households have very little to sell for income,
poor household food base because the families do not produce enough for
own consumption yet even the little produce is all sold to get an income.
Another manifestation is poor nutrition standards.
Zone 2
This is an area with high food / cash crop production. The problems of
food security are defined in a different way from zone 1. In this area,
the production is really sufficient to meet household food / cash requirements
in some months of the year. However, due to non existence of preservation
/ storage mechanism; and limited access to markets, much of the crop get
spoilt or damaged.
The resulting fate is that of food insecurity and poor incomes. In some
months, there is seemingly too much production reaching a climax in a
given month. Yet in other months, there is nothing or very little. This
is characterised by high increase in food price
3.0 Introduction of the solar drying technology:
Sun drying though is a process familiar to all farmers in the district.
The method is used by farmers to dry crops like coffee, millet, sorghum,
maize, beans, groundnuts, cassava, potatoes, etc. Some farmers even dry
meat using the sun. However, for perishables crops such as bananas, tomatoes,
pineapples, mangoes, and other related fruits / vegetables, there exists
no mechanism for preserving them.
The appropriate solar drying technology therefore addresses the problems
affecting such crops that cannot successfully be dried used traditional
sun drying methods.
3.1 Steps taken to introduce the technology:
As mentioned above, there exists few food preservation mechanisms in
place in the district. This further implies that the habit of food storage
or preservation is not deep rooted in the cultures of the people in Karagwe.
The whole idea of food preservation and storage is therefore something
alien and comparatively new.
In 1995, FADECO introduced the project for the first time to dry tomatoes
and cabbages. Many people could not believe this could work. After several
attempts to convince the farmers that this was a simple way of preserving
the crops had failed, an idea was sought to take a few farmers on a study
visit to projects in Uganda that were involved in solar drying. This was
successfully done in October 1995 as a first step to raise the awareness
of the first group.
In 1996, the first solar dryer was constructed at Nyakasimbi. Trials
were conducted with a wide range of perishable crops including tomatoes,
pineapples, paw paws, bananas, cabbages, etc. The project in its infancy
slowly attracted the attention of farmers from other parts of the district.
The desire then to spread the technology grew and ways and means were
sought of how to further the technology to interested farmers and groups.
This was not an easy task. There are many things to consider like logistics
and finance. The dream was not realised until 1997 when a proposal was
submitted to GTZ and when it was successfully considered, a plan of action
was designed for technology transfer. The achievements to date of the
project are thanks to the support received from GTZ/ISAT/GATE.
3.2 Challenges:
3.21 Attitude change:
It has taken the project a lot of effort to implant the idea of post
harvest storage into the minds of the farmers. Sun drying is well understood
for crops like coffee but for bananas, this was unheard of before.
3.22 Habits:
Food preservation is not a habit commonly practised. Most people were
unaware of the possibilities and further advantages of storing food either
for later consumption by the family or for sale to earn an income.
3.23 Resentment:
Some people resented change. The technology brought new agricultural
revolution and enlightenment. Some people claimed there was no need to
preserve crops because there was always enough. Government extension staff
tried to disqualify the technology that it cannot work.
3.3 Achievements:
3.31 Acceptability:
The project has gained wide acceptance by the entire farming community,
and gained root among farmers, extension workers, researchers and government
officials. It is seen as addressing actual needs of the farmers, by providing
an alternative to post harvest preservation and storage of crops.
3.32 Influence on district development planning policy:
The project has brought to light the necessity for food preservation
to counteract the negative consequences of food insecurity and household
income. 1999 district development plan has included an aspect on post
harvest demonstration to be implemented under both the agricultural department
for food security and under the Community development department as an
income / employment generating activity to groups and individuals.
3.33 Government recognition:
The project has gained much support in its later stages from both local
and central government officials. The district and regional commissioners
have been instrumental in furthering the spread of the technology. They
have supported the project morally and have made the activities of the
project easy by offering necessary documents without any problems. The
Vice President of Tanzania visited the project early in November 1998.
This gave the project wide national publicity in the press, television
and on radio.
3.34 Support to Government policy on poverty eradication and food security:
The main objective is to promote food security and work towards poverty
alleviation. This is a national call. The project is positively contributing
to this, something that is in line with the government plans for national
development.
5.0 Methodology:
Much of the project activities concentrated on technology transfer through
meetings and training workshops.
4.1 Meetings with stakeholders:
One day introductory meetings were held in all identified pilot villages.
These meetings targeted village leaders and key informants. These were
aimed at introducing and laying ground for the project. During these meetings
were discussed the importance and the benefits of food preservation. During
these same meetings, partners were identified, any existing mechanisms
were discussed. After such meetings, organised workshops were arranged.
4.2 Workshops / Seminars:
These are three days intensive training to selected target groups. Women
groups, Youths groups and individuals farmers have always been a target
for these workshops. Village leaders have also been welcome to specialised
training concentrated on the following:-
4.3 Follow up and on-going training:
Regular visits have been conducted to groups and individuals who have
undergone training. With the presence of a trainer attached to the centre,
it has always been possible to offer informal training to more farmers
outside normal workshop schedules.
4.4 Operational Research:
Technology transfer has been combined with operational research. Several
crops have been dried including coffee, pepper and herbs. Cassava and
potatoes have also been dried using solar dryers.
Solar dried banans have been ground to flour and confectionary products
: banana bread, banana biscuits and banana cakes made with or without
the addition of other ingrediedienst especially sugar.
5.0 Economic information regarding the cost of the drying Process:
5.1 Seasons:
Apple bananas are available the year round. Pineapples grow from March
to May; Mangoes from Jan. Feb. and from May - June; Paw paws from Jan.
- Oct. There is continuity of supply of bananas and pineapples for drying.
Mangoes are seasonal whereas paw paws are also available the year round.
5.2 Growing process for different crops:
- Bananas ( mussa spp.) is the most important crop are grown
from suckers and mature in 8 months. With good care, they can produce
well for 10 - 15 years. Bananas are picked green and ripened by covering
with either polythene or other materials.
- Mangoes ( mangifera Americana) are grown from seed from the
mother fruit although grafting is also possible. They take from 18 months
( grafted) to 5 years if planted from seed to mature.
- Paw paws ( papaya carica) are grown from mother seed and take
between 5 - 6 months to mature. They last less than 4 years and are
easily felled by wind.
- Pineapples ( ananas) are grown from suckers. The bigger they
are, the sooner they produce. They take from 18 months to mature and
bear for over 5 years with diminishing yields. Pineapples mature 4 months
after flowering so there are 2 crops per year in the two rain seasons.
3.3 Labour requirements:
In the villages, bicycles are the main means of transport used mostly
by men. On the farms, women do the heavy carrying. All family members
are involved. There is no mechanised labour. Much of the labour on the
farm is provided by the family members. Hired labour is possible from
some peo0ple in the village who want to earn some income. One issue that
most people find it difficult to estimate a cost for their own labour.
5.4 Preparation:
The fruit must be prepared at dawn or when it is clear depending on what
the weather conditions will be. Fruit must have maximum sun the first
morning. The best fruit is healthy, disease free, fresh, ripe but not
over ripe. A chlorine bleach commercially called JIK is used to clean
the trays, work surfaces, fruit, knives and buckets.
Fruit must be cut to the correct thickness ( gained also through experience).
Pineapples and mangoes 2 -3 mm; bananas to 5 mm. The slicing is done manually
by hand to the size specified. It is difficult at the beginning but slowly,
people gain experience. The idea of slicing machines has been thought
but it is unlikely to work. Mr. Graham Anstee from NRI advised that these
slicing machines were too expensive and not applicable to fruit slicing.
He rather suggested techniques as those use in catering. Waste is composted
far from the area. People usually cover their heads with hair nets.
5.5 Drying:
It is essential that fruit is first dried on a sunny morning. The first
morning is very crucial. Fruit must be in the dryer at least before 11.00
A.M. The dryer position is very important. It should be away from the
shade, on a dust free site with no litter around. Trays should be loaded
so that there is air circulation between.
Doors should be securely closed to keep out insects and kept so closed
until the fruit is dry. Sliced fruit should be dry before removing. removal
should be in the late afternoon. Drying time varies according to weather
conditions. The following is the average drying periods in sunny weather:
- Pineapples 2 - 3 days
- Mangoes 1 - 2 days
- Bananas 2 - 3 days
- Paw paws 1 - 2 days
5.6 Cost of the drying process:
Drying is a process that removes most of the water from a food to give
a long shelf life and/or to increase the convenience and value of the
food. Considered under this technology are the low volume high value foods
especially fruits and vegetables. Let us consider the process flow for
these crops.
Process Notes:
Harvest
This should be done as carefully as possible to prevent spoilage,
bruising & loss of quality during transport to farm gate.
Wash
Use clean water to remove dirt or soils. Usually a mild disfenctant/
bleach called JIK is used.
Sort / Grade
This is needed to produce a uniform size dried product. Foods are sorted
for colour, size, shape and maturity. Uniform size and maturity influence
drying time. Sorting is done by hand.
Peel / Slicing
It is usually done by hand using sharp stainless steel knives. After
peeling, fruit is cut in proportionate slices to facilitate the drying
process.
- Pineapples 2 - 3 mm
- Mangoes 2 - 3 mm
- Bananas 5 mm
- Tomatoes 3 - 5 mm
Dry Rate depends on temperature, relative humidity and speed of air,
type of dryer and size of food pieces.
Temperature and Humidity:
Air contains water vapour and the amount of water carried by the air
varies with its temperature. At higher temperatures the air can carry
more water vapour than at lower temperatures, so to dry foods, it is necessary
to raise the air temperature and hence obtain a lower relative humidity.
Air Speed:
Faster moving air carries away moisture more quickly from the food and
he food therefore dries faster than in slow moving or stationary air.
The air speed could be increased by small fans or by heating the air using
other forms of fuel.
Technically, during the initial stages of drying, water is lost from
the surface of the food and the drying rate is controlled by all three
factors mentioned above. In later stages, moisture moves inside the food
to the surface. Here the rate is controlled by the temperature of the
food. The air speed and relative humidity have a much smaller effect.
In both the initial and later stages of drying, the size of the pieces
is very important. In the first stage, smaller pieces have a greater surface
area for water to evaporate from. In the second stage, the smaller the
pieces the less the distance the moisture must move to reach the surface
of the food.
Package / storage
Packing is carried out immediately after unloading since dried slices
will re-absorb moisture and be susceptible to attack by insects and other
pests including moulds. Dry plastic bags are supplied by the project to
the producers. Dried fruits must be stored in cool, dry and clean containers
which are secure and protected against rodents and pests.
5.7 Management of the drying process:
These are some essential aspects to keep in mind:
5.71 Hygiene and cleaniliness:
All utensils : knives, bowls, trays, etc. use in the drying process need
be extra clean. Some investment has to be spent in buying things like
soap, JIK, etc.
5.72 Quality issues:
Quality needs to be maintained and checked every time. A set of quality
control measures exists and a checklist is in place for all steps to be
taken.
5.73 Sun and Solar drying:
To find out whether ( and when) sun/ Solar drying is possible in the
participants communities, the harvest times, food prices and weather patterns
can be compared in that region using the weather graphs. Sun drying is
traditionally done in areas where in an average year the weather allows
the food to be fully dried after harvest.
The main advantages of sun drying are low capital and operating costs
( drying equipment are not used) and little expertise is required but
has many problems associated with this method as follows:-
- theft or attack by insects, rodents and birds
- contamination with dust, dirt, animal droppings, etc.
- no protection from rain
- slow or intermittent drying which increases the likelihood of spoilage
- relatively low quality products and variable quality due to over
or under drying
- relative high final moisture content and spoilage during storage
- large areas of land need for the shallow layers of food
- laborious because the crop must be turned, moved if it rains and
- animals must be kept away while the drying takes place
- direct exposure to sunlight reduces the quality ( colour and vitamin
content) of some foods.
The quality of sun dried foods can be improved by the following methods:
- sort, grade and clean the food
- reduce the size of pieces or slice to desired sizes
- cover to prevent insect damage
- shade if necessary to protect colour or flavour of food
- protect from animals or birds
- cover for rain or dew at night
5.76 Solar drying has advantages over sun drying as follows:
Solar dryers operate by raising the air temperatures to between 10 -
30 C above normal air temperature. This makes the air move through the
dryer and also reduces the humidity. The higher air temperatures deters
insects and the faster drying rate reduces the risk of spoilage by micro-organisms.
These factors greatly improve the quality of the product. The higher drying
rate also gives a higher output of food and hence a smaller drying area.
Food is enclosed in the dryer and therefore protected from dust, dirt,
insects, birds and animals. The dryers are water - proof and the food
does not therefore need to be moved when it rains or at night to protect
from dew. Finally dryers can be constructed from locally available materials
except for the solar plastic at a relatively low cost.
6.0 Cost benefit analysis of the solar drying enterprise at Mabira
A proper costing of the project needs to be made with specialist / consultancy
assistance. Most people do not know the value of land and they do not
cost their labour. For this reason, it has been difficult to come out
with a substantial cost of production for the different crops.
The price calculation given here below has been costed as the farm gate
price.
Product: Sweet bananas
Size: average size bunch output of dried fruit 2 Kg.
6.1. Costs:
a) cost of fruit of average size
price per bunch 100/-
Number of bunches that fill a tray 1
Number that fill dryer with 12 trays 12
cost of filling dryer in 2 weeks drying cycle 1200/-
i.e. in one week dryer is loaded twice (4 times/2 weeks)
Labour for filling dryer ( 600/- x 4) 2,400/-
b) Cost of transport:
return trip to Kayanga done one a month 2000/-
c) Cost of maintenance:
repairs, consumable 1000/-
(i) Total costs involved: 6,600/-
INCOME:
After drying:
Price received / Kg dried fruit 500/-
quantity of dried fruit per tray (Kg) 2
quantity of dried fruit/ dryer of 12 trays (Kg) 24
Income from one drying cycle (24 x 500/) 12,000/-
(ii) Income per two week cycle 12,000/- x 4= 48,000/-
Net profit ( Income - total costs) [ii - 1] 41,400/-
6.2 Cost calculation of different dryer sizes
If for instance, a farmer or group invests in one 12 tray dryer, he is
likely to receive at least TShs 41,400/- as net profit. If he takes off
50% as repayment for the dryer, he remains with 41,400 - (50% of 41,400)
= 20,700/-. He would have a monthly net revenue of 20,700/-
If he maintains this revenue, it would take him 230,000 / 20,700 = 12
months to pay back for the dryer. The revenue is even hire if he could
manage several dryers at the same time.
7.0 Project achievements:
7.1 Training of farmers' groups:
The project has been able to extend to conduct training seminars to 6
other new villages. The methodology followed in these was slightly different
from that employed in the first phase. Familiarisation visits were conducted
to meet with local government authorities in concerned villages and to
identify existing and interested groups. There after, a training program
was worked out for all the six villages and a time table was made.
3 day workshops were conducted which included both the practical aspects
of dryer construction, fruit processing and business profitability. The
experience gained in the first phase was widely integrated and used. The
following is a table showing the number of people trained.
No. of beneficiaries trained per month by village/ centre:
No of groups identified and trained:
7.2 Dryer construction:
7 more dryers have been constructed in addition to the already existing
10 dryers. Unlike before, dryers originally owned by the project, have
been loaned to interested groups. The new ones have been constructed and
directly loaned to interested groups under the responsibility one selected
member of a group.
Conclusion:
The project has received wider acceptance. More on solar drying is treated
elsewhere on this website . If you wish to read more about solar drying
click on the link marked solar drying in the site map.
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