What you need to know:
The solar dryer helps farmers to ensure their products such as maize, bananas, cassava, mangoes and pineapples don’t ferment or lose their content, writes Denis Bbosa.
The weather has become extremely erratic, making it harder for farmers to know when to plant, harvest and more importantly, dry their produce as they have done over the years.
It is currently raining heavily in some parts of the country at a time when farmers, in particular those growing maize, should be harvesting their produce.
The unpredictable weather makes the traditional drying of various farm produce under the sun harder.
Luckily, there are various technologies to help you dry your produce for a longer shelf-life, some of which have been unveiled by Makerere University Agricultural Research Institute, Kabanyolo (Muarik).
These produce include fruits, grains, fish, tubers, oilseeds and all-manner of vegetables.
This dryer has three main parts; greenhouse, a flatbed compartment that holds produce, which is covered with a transparent polythene sheet and an air inlet.
David Buule, an agronomist at Muarik, who is behind the technology, says it is made of a nylon sheet, wood and wire mesh that helps absorb heat. The mesh is made from metal to prevent corrosion and ensure the food is not contaminated.
At the rooftop of the dryer is an inlet that allows air into the chamber. “To use the dryer, one first cleans produce such as banana, then chops them into smaller pieces and puts on the mesh. After two to four hours depending on the heat intensity, banana dries,” he said.
The machine can dry up to 200 kilogrammes of vegetables at a go, prolonging the shelf-life to over a year, according to Buule.
He says one can make the dryer at home or on the farm since the materials used such as timber, mesh and polythene sheet are locally available.
Why solar dryer?
According to Buule, farmers need to make a gradual shift from using the rudimentary means of drying their produce to the solar-based drying.
“The direct solar dryer where the heat hits the plastic and returns to the crop, in ours, the sun directly hits your crop, the cover keeps the warm (greenhouse effect) our dryers go up to 17 degrees. We control the warmth for optical drying conditions to our crops,” he reveals. Among other benefits, the solar dryer reduces contaminations, avoids fungal growth that cause aflatoxins thus less post-harvest challenges.
The greenhouse has fans to control temperatures and the dryer is affordable after cost benefit analysis. Their solar dryer that cost them about Shs15m to construct, is big enough to accommodate 10 tonnes and dries everything including cowpeas, pumpkin, cassava maize and fish. “This offers clean energy, you have to have a clean base, we dry from an elevated platform no dust, the duration of drying maize outside is two weeks but here three days to get to 15 per cent, coffee three days on the sunny days and four on rainy, decreases on labour force even if you have five tonnes already on mesh tray a single farmer van handle.”
Barbara Balungi a nutrition scientist, says use of solar drying technologies is key to lowering post-harvest losses, which stand at 20 to 40 per cent.
She observes that drying of grains helps to curb aflatoxins that pose health risks to consumers.
“Research has also shown that consumer acceptability of dried fruits and vegetables ranks higher than the fresh one. The nutritional value of dried produce drops slightly and it is better to have them on the table in required amounts rather than reducing the servings when the prices go up,” notes the expert.
Balungi adds: “Every household that has a garden should never allow post-harvest losses to occur when there are several technologies, a good number of them home-made .”