An overview of growing potatoes
POTATOES are grown globally and are the third most consumed crop after wheat and rice. Potatoes scientifically known as Solanum tuberosum, belong to the Solananaceae family and originate from South America, specifically the Peru-Bolivia region.
Potatoes are a high value crop that has seen ever-increasing demand in different market segments of Namibia. On average, N$14 million is spent on potatoes by wholesalers, retailers, and fast-food establishments every month.
Growing potatoes can be quite a profitable venture for farmers, however, yielding a good return on investment from this crop, requires fundamental understanding on how this crop must be grown and nurtured.
To this end, before one decides to venture into the production of potatoes, it is essential to understand the fundamental requirements of the crop, specifically it’s morphology and growth stages.
When considering potato production, it is important to note that potatoes grow best in deep and well-drained loamy and sandy loam soils with a pH level between 5.0 and 7.0. It is also essential that the soil contains organic matter that can supply the necessary nutrient reserves.
It is therefore vital to carry out a soil analysis to determine the fertility levels of your soil to help you develop a fertilization programme for your potato production.
Another consideration is the climatic conditions of the area in which one intends to grow potatoes. The optimum temperatures for growing potatoes range between 7 to 30 degrees Celsius.
In temperatures that exceed 30 degrees C, potatoes usually experience a slowdown of carbohydrate accumulation in the tubers, resulting in small tubers. An important point to note is that potatoes are susceptible to frost and extremely cold temperatures, therefore, the best time to plant potatoes are September to January and February to the end of April.
During winter avoid growing potatoes as it may result in crop failure and major financial losses for a farmer. To establish a successful potato production enterprise, the cultivation of the soil must be done correctly.
Primary tillage using mouldboard ploughs and disc rippers must be done to a depth of 30 cm. Moreover, it is essential to apply basal fertilizer (400–500 kg of Superphosphate 10.5% and NPK 3:1:5) depending on the fertility levels of your soil.
The seed beds on which potato tubers are to be planted must be raised to a height of 35 cm using a ridger that has a width of 45 cm. Furthermore, it is recommended that potatoes must be planted at spacing recommendations of 75 cm between rows and 30 cm within rows and the sowing depth of the seed potatoes (tubers with sprouts) must be 10 to 20 cm.
To prevent fungal diseases in areas where humidity is relatively high, farmers are urged to utilize the drip irrigation system which only allocates water to the stem of the growing potato plants.
Additionally, farmers must re-ridge the seed beds at least three times to cover the tubers forming on the roots to prevent the greening of the tubers. Weed control is also essential to enable potatoes to grow without competition from unwanted plants.
Furthermore, during the production cycles, farmers are urged to keep production and financial records which are all essential to evaluate the profitability of the business.
As a precaution, inexperienced farmers can always trial potato production on a small-scale operation. During this period, a beginner farmer should learn important aspects of production, note down challenges and how to overcome them and ensure that a good insight into the crop is gained before they can scale up production.