By Duncan Mboyah
Post harvest losses and climate change are threatening the existence of African indigenous leafy vegetables, scientists say. The scientist blames postharvest losses to lack of cold stores for farmers to store their vegetables after harvest, poor transportation, bad roads, bad packaging and unhygienic markets.
“Kenya alone loses 50 percent of the vegetables annually, hence the cause of food insecurity, malnutrition and poverty in most growing areas,” Mary Abukutsa–Onyango, Deputy Vice Chancellor in charge of Research Production and Extension at Jomo Kenyatta University of Agriculture and Technology (JKUAT) said during the recent African Indigenous Vegetables, HORTINLEA project annual meeting.
Abukutsa–Onyango emphasized that the vegetables are in high demand, post harvest losses means farmers loose in farm inputs, water, money and savings. She revealed that African nightshade, amaranthus, spiderplant, vegetable cowpea, slender leaf, jute mallow and Ethiopian kale are highly threatened.
“If we can reduce postharvest losses in African leafy vegetables, we will be able to increase available food and also improve food and nutrition security; these vegetables are becoming more popular because they contain a lot of vitamins, minerals and anti-oxidants which help in curing or preventing some non-communicable diseases,” she said.
Winifred Chepkoech, a researcher on traditional African vegetables says that changes in climate that leads to increased temperatures, increased frequency of droughts and dry spells, late onset and early retreat of rainfall further complicates the future of these valuable vegetables.
Farmers continue to experience frequent attack by pests and diseases, low yield, water-logging and prolonged droughts and dry spells and are equally unable to irrigate the vegetables due to lack of enough water that is linked to climate change,” she said.
Chepkoech observed that unless farmers learn to monitor weather, invest in rain water harvesting, invest in efficient irrigation methods like drip and sprinkler irrigation, apply mulch to their vegetable garden, adopt organic remedies for pest control, apply integrated pest management to reduce environmental damage and use certified seed varieties the vegetables risk disappearing.
However, she explained that by switching varieties such as slender leaf, Amaranth, cowpea, jute mallow and African spinach that are more resistant to pests and diseases and tolerate extremes in rainfall and temperatures can save farmers.
Wolfgang Bokelmann Head of the Division Economics of Horticultural Production at Humboldt-University in Germany and Principal Coordinators, HORTINLEA project noted that AIVs have high level of nutrition and health benefits as they provide essential micro-nutrients and reduce obesity, but they are unavailable due to low supply.
He attributed low supply to several factors including poor quality seeds, low soil fertility, water scarcity and unreliable rainfall resulting in the vegetables not readily available during certain months when it very dry.
“There is need to embark on preservation measures to help reduce postharvest losses when the vegetables are plenty,” he added.
Eliud Wafula, a researcher in post harvest technologies of African indigenous vegetables recommended drying and fermentation as methods that could be adopted in preserving the vegetables to be used during periods of scarcity.
“Fermentation is readily available and cheap as it only requires selected lactic acid bacteria to prevent the growth of pathogens and vegetables have better taste, smell, clean and safe for consumption,” he noted
Wafula added that fermented leafy vegetables can be kept for a long time without significant reduction in quality and nutrient content. He observes that where there is no refrigeration (fridge), fermentation can be used to store these leafy vegetables for a long time without losing nutrient content.
The scientists in the HORTINLEA project observes that for farmers to benefit from growing the vegetables they should add value by drying of vegetables for preservation, do certification of ready-to-cook AIVs and have loans to enable them venture into serious large scale farming.
Elisha Gogo, a researcher on African indigenous vegetables encouraged farmers to use Modified Atmosphere Packaging (MAP) to keep the leafy vegetables for a long time as opposed to pouring water at intervals on them.
He said that if MAP is used for packaging the vegetables, and stored under normal conditions oxygen decreases inside the package from 21 percent to about 16.5 percent on the other hand, carbon dioxide in the package can increase from 0.03 percent to about 3.3 percent.
AIV farmers have been selling the vegetables directly to supermarkets, hotels, schools and hospitals. Majority of farmers sell at open non shaded and closed markets.
