The Sunday News
Dumisani Nsingo, Senior Farming Reporter
MRS Emma Sithole (52) is furious at farming experts she believes “duped” her into going into sack potato production with the promise of high yields.
Mrs Sithole is part of a 10-member women’s co-operative, Hama Mawoko, in Sizinda suburb, Bulawayo, which ventured into sack potato production about two years ago.
At the time, this type of farming was being touted as the answer to commercial agriculture in towns and cities, where residents do not have the luxury of vast expanses of land to carry out farming.
The business venture, which took city dwellers by storm, was said to be capable of giving a farmer an excess of 15 kilogrammes of potatoes from one bag, although it later turned out this could have been a paper assumption.
Members of Hama Mawoko ventured into sack potato farming in 2014, after realising a market gap as the demand for potatoes in Bulawayo and in various parts of the country rose due to depressed production in farms, prompting the influx of imported potatoes mostly from South Africa.
“In 2014 we embarked on sack potato production, this was after we realised that there was a ready market for the product. The fact that the concept had been said to be a success in Harare prompted us to start it, as we saw it as an ideal income generation initiative, which of course was less laborious,” Mrs Sithole said.
Sack potato farming is a concept where potatoes are grown from sacks as a way of dealing mainly with shortage of space.
The method involves filling a potato bag with good quality multi-purpose compost to around 2,5 centimetres below the rim.
Farmers then put a single potato tuber into the compost with the shoots pointing upwards, to a depth of 12 centimetres.
The tubers are then covered with compost and then farmers need to place the bag in a bright position and constantly water them.
Additionally farmers will need to apply fertiliser and additional soil as the plant grows.
Although members of Hama Mawoko vouch that this is exactly the steps they followed when they embarked on the project, the results were never satisfactory.
The co-operative grew 300 bags of potato plants and a splendid germination rate brought smiles to the group as prospects of an optimum yield looked attainable.
However, the members were to be left dumbfounded upon harvesting, as it turned out that it was only the green leaves that were flourishing, while most of the tubers failed to mature into fully fledged potatoes.
“The germination rate was very encouraging, even the growth of the leaves was marvellous and we even hosted a party to celebrate in anticipation of a bumper harvest. But to our surprise, instead of getting 25 potatoes that we were told that each sack could produce, ours were producing two or three potatoes while some produced nothing,” said Mrs Sithole.
The co-operative was forced to quit potato farming after the disastrous results, switching to dishwashing liquid production.
“Up to now we really don’t know where we went wrong. We even had an extension officer from the Department of Agricultural Technical and Extension Services who was assisting us to ensure we attained an optimum yield, but all this was in vain,” Mrs Sithole said.
Matabeleland North Department of Agricultural Technical and Extension Services (Agritex) provincial officer Mr Dumisani Nyoni said sack potato production failed to meet the desires of most urban farmers largely due to misinformation by facilitators of the programme.
“Initially people were being told that they will get 15 to 20 kilogrammes of potatoes from a sack, leading to a hype among farmers and aspirants while the maximum per plant was around two kilogrammes.
“The water management for most of the farmers was poor and somehow people were made to believe that growing potatoes in sacks was better than on the ground. As a result they failed to produce to the level expected, so they quit, but some persevered,” he said.
According to Agritex, in sack potato production, constant water supply is critical throughout all the growth phases of the crop, more so during the stages of tuber initiation and tuber enlargement.
In order for the crop to yield as expected, the farmer should ensure that moisture levels do not drop below 65 percent of field capacity, noted Agritex.
It said water stress in young plants would lead to premature tuber initiation.
This leads to yield losses due to the fact that the tubers commence development when the canopy has not developed enough to support the tuber bulking process as expected.
This scenario results in a huge number of small tubers despite the level of fertiliser application.
Conversely, if moisture levels are sustained at levels above field capacity, yield is negatively affected due to leaching effect as well as oxygen denial of the roots. Not only is the yield affected, the same goes for the cooking quality of the produced vegetable.
So, advised Agritex, irrigation of the potato crop should be matched with the respective water-holding capacity of the soils so as to maintain the moisture at field capacity.
Some farming organisations, however, believe that not enough research was done on issues such as varieties and suitability of the soil that most of the farmers used, which contributed to the poor results.
Matabeleland Young Farmers’ Association chairman Mr Ayanda Ncube said sack potato production had failed to achieve desired results owing to poor seed varieties.
“Most of the seed producers or providers sold farmers sub-standard seed instead of providing them with pedigree ones and ultimately this led to poor yields,” he said.
A research study focusing on why sack potato farming failed done by Agri-Universe Zimbabwe, which provides technical support to farmers, noted a number of issues that farmers could not have done correctly resulting in poor results.
The research, done later in 2014, noted that as the concept grew, farmers expected almost similar results, yet conditions were different.
“Sack potato farming has been attempted in all parts of the country that is from natural region I to V. One can imagine the variations in soil types and climatic conditions that the crop has been grown under yet all looked forward to similar yield,” noted the research.
It also pointed out that as a result, farmers ignored a number of factors which suited their regions.
Factors which needed to be looked at in each area, according to Agri-Universe Zimbabwe, included water management, season of establishment, soil type and fertiliser application and seed physiological age.
The organisation added that the physiological age or generation of the seed that one uses to establish their potato crop remains important whether the farmer uses seeds, seedlings or tubers.
Aged seed tends to produce potato plants with numerous stems that sprout and develop rapidly and die early. High stem numbers usually result in a high number of tubers per plant, which reduces average tuber size by reducing the amount of carbohydrates available to each tuber during bulking.
Early death also shortens bulking time and limits overall productivity. By comparison, plants from physiologically young potato seed begin to bulk later than those from aged seed, which may shorten the linear tuber growth phase in areas with a short growing season.
“We thought we had stumbled on a gold field but like any other business there are risks and in our cases, this turned out to be a wild goose chase,” said Mrs Sithole adding that experts must be honest and truthful especially when introducing new concepts to farmers.
