Jetwell Mugabe-Molecular Biologist, TRB
SWEET potatoes (Ipomoea batatas) are a Convolvulaceae family dicotyledonous plant. Sweet potatoes are grown (Figs. 1 and 2) for their high yields and, to a degree, drought tolerance, as opposed to maize, which is used as a household carbohydrate source.
Tuber uses in industry will almost certainly absorb realised yields and help to keep crop prices stable. If its production and consumption are approached holistically, sweet potato can help Zimbabwe’s economy grow.
In the food processing and manufacturing industries, the crop has enormous potential. The total national yield for the season 2020-2021 was 422,618 tonnes, up from 114,558 tonnes the previous season (2019-2020). Only maize (2,717,171 tonnes) produces higher annual total yields in Zimbabwe.
Environmental requirement
Sweet potatoes are incredibly adaptable, allowing them to be grown almost anywhere in Zimbabwe during the rainy season. The plant is tropical in origin and cannot withstand frost. It thrives in climates with an average temperature of 24°C, plenty of sunshine, and warm nights. Sweet potato requires 750–1,000 mm of rainfall for optimal yields, though 500 mm can suffice in a growing season to achieve close to optimum yields.
Tuber initiation, which occurs 50 to 60 days after planting, is the most critical and sensitive growth stage for water requirements in the crop. If aeration is poor, the crop is susceptible to waterlogging, which can cause tuber rot and stunt storage root growth.
Dark soils with signs of water logging are not conducive to long-term production, and sandy loamy soils are more preferred. Although some soils that are prone to cracking can expose the tuber to pests and diseases during development, dip, well-drained soils are the best. Sweet potatoes do not flower in Zimbabwe because they flower under short days of 8 hours and vegetative propagation is the only option.
Nutritional Value
This crop has the ability to combat malnutrition, which is still prevalent among Zimbabwean infants. Malnutrition is still prevalent in Zimbabwe and one out of every two Zimbabwean children were malnourished in 2020 (UNOCHA, 2020). Sweet potatoes (Fig. 3) nutritional value is unparalleled, second only to avocado. It is a nutrient-dense crop that provides a small amount of everything that the human body needs.
In addition to being a good source of carbohydrates, they also contain some protein, albeit in small amounts. Fats, fibre, and vitamins are also present. Vitamin A, Vitamin C, Niacin, Vitamin B6, and pantothenic acid are some of the vitamins that are in sweet potatoes. Sweet potatoes also contain important minerals like potassium, manganese, and copper.
Chlorogenic acid and anthocyanins are two other important compounds found in sweet potatoes. Antioxidants with anti-aging properties can be found in orange-fleshed and purple-fleshed sweet potatoes. Sweet potatoes promote gut health and may also have cancer-fighting properties due to the presence of anthocyanins.
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