By Prisca Kabwe Nyirenda
For many years Zambia is known to grow and export traditional crops such as wheat, cotton, tobacco, and maize among others.
In the recent past, the country has achieved some milestones with regard to new high value crops gaining international market through the process of market access which among other aspects, involves satisfying Phytosanitary requirements of the importing country.
One of the new high value crops that is being produced in the country and is already on the international market is Stevia also called Stevia rebaudiana.
The commercial growing of Stevia started 2 years ago and about 22 farmers in Zambia are currently involved in the production of the crop. The dried Stevia leaf is currently being exported to China.
Sarah Trouw the proprietor of Jalikenasa farm in Choma district is the pioneer of Stevia cultivation in Zambia. She explains that her interest to grow Stevia came from a market perspective which prompted her to explore means of starting to grow it in Zambia.
She explained that the initial seedlings of stevia were sourced from Kenya with assistance from Pure circle a company that is also providing market for the crop.
Mrs. Trouw explained that Stevia is part of the sugar substitute market and the demand for the use of Stevia is growing big because globally many people are concerned about healthy conditions such as obesity, High blood pressure and diabetes among others.
What is Stevia?
It is small bushy plant which grows to a knee height. Stevia is a natural herbal sweetener which is used in food and beverages. It is the no- calorie source of sweetness and a substitute for cane sugar. Stevia has no carbohydrates or artificial ingredients and research shows that in some cultures around the world Stevia is used as a medicinal herb.
Mrs. Trouw said currently, there are two varieties of Stevia being grown in Zambia, PC 1 and PC 3. PC 1 is said to be three hundred times sweeter than the cane sugar while PC 3 is said to be a thousand times sweeter than cane sugar.
“Stevia can actually be used domestically in people’s homes instead of using sugar in tea or in baking one could use Stevia in powder or liquid form”. She said.
Mrs. Trouw said the potential health benefits of the crop give an assurance for continued market availability.
So how exactly is the Stevia crop planted?
Michael Brown of Mukaziwa farm in Kalomo district explains that it has to be vegetatively propagated by cutting pinching from the mother plant and stick them in the seed bed to come up with seedlings which are ready after 30 days.
And Fredas Siachitema a nursery Manager at Jalikenasa farm in Choma explains that to enhance rooting, Cosmo root chemical is applied and to speed up the growth Cosmo feed which is a fertilizer is applied in the seed bed.
Ms. Siachitema said Stevia crop thrives well in heat and so the seed bed is covered with a plastic to quicken germination.
She said in hot season the stevia nursery takes seven days to start rooting and in cold season it takes 10 to 12 days.
She said management of insects and diseases coupled with watering and balancing of temperatures is critical in raising stevia nursery.
Though Stevia is a plant native to South America, it is proving to be quite adaptable and capable of being cultivated in different climatic zones. In Zambia, it is currently being cultivated in Mkushi, Choma, Kalomo, Magoye, Chirundu, Livingstone and Chisamba.
Zambia’s climate has been described to be even advantageous for the Stevia crop as it can be grown as a perennial crop contrary to how it is grown in China and other parts of the world where it is grown as an annual crop.
Mrs. Trouw said Zambia is poised to do well because the quality from Zambia has been appreciated on the international market. This is because the crop thrives well in temperatures between 25 to 35oc. And the quality of sweetness in stevia comes from the sunshine through the process of photosynthesis.
She said Zambia’s climate assures continuity of supply because it has a stable day length hours of about 13 hours in summer and about 11 hours in winter making it possible to have 3 to 4 harvests in a year unlike the way it is harvested only once in some countries.
Mrs. Trouw further noted that Zambia has a defined short rain season which allows the crop to grow well as too much overhead rainfall throughout the year leads to humidity which causes a lot of diseases.
She observed that Zambia is blessed with 40% of surface water and so most of the Stevia growers are using water from the dams as well as ground water from boreholes for irrigation.
Solomon Marx of Samona Zambia Limited based in Kalomo district is one farmer who is enthusiastic and determined about growing Stevia. Having experience in cultivation of 85 hectares of stevia says stevia is a horticultural crop in nature and requires good management.
Mr. Marx says it is important to control weeds, diseases and insects so that you produce quality product for export.
He has described Stevia as a smart crop because one does not need to incur planting costs every year. It can be planted at any time of the year and once it is planted, it remains in the field for 4 to 5 years as one continues to harvest 3 to 4 times each year.
Mr. Marx further noted that the benefits of growing stevia will trickle down to the environment as drying of stevia is done within 24hours unlike the amount of time required for drying tobacco which takes 5 to 7 days using enormous amount of logs which are cut leading to deforestation.
“We want to dry stevia as quickly as possible, if stevia doesn’t dry within 24 hours, you start losing the quality in terms of sweetness”, he said.
Rodney Mackey of Munyati farming in Choma district is one farmer who has downsized tobacco production and diversified into stevia production standing at 64 hectares.
Mr. Mackey says stevia is proving to be a better rewarding alternative crop due to the already existing infrastructure on the farms such as the drying kilns.
He said the crop has great potential to contribute to the country’s economy as it gets foreign currency from the exports of Stevia to China.
In line with the Zambia and China agreement for Stevia export, the Plant Quarantine and Phytosanitary services has to supervise the process of growing, processing fumigation and storage of the crop.
Martin Siazemo a Plant Health Inspector under The Plant Quarantine and Phytosanitary Services (PQPS) of Zambia Agriculture Research Institute (ZARI) noted that inspections
of stevia nurseries and fields are a requirement to check for weeds, pests and diseases so that there is compliance to the Phytosanitary requirements of China.
Mr. Siazemo said that the unit remains alert to maintain market access of Stevia to China by ensuring that all the Phytosanitary requirements of the importing country are ever satisfied.