This archive report was first published on 21 August 2021.
Kenya is one of the largest producers of Irish potatoes in Africa, with the crop being the second most important food crop after maize. According to the National Potato Council of Kenya (NPCK), potatoes are popular and marketable, making them a lucrative business for farmers.
Victor Kariuki, an Irish potato farmer from Molo, shared his expertise on production for commercial purposes. He emphasized the importance of selecting the right site for potato farming, stating that the land should not have been under any other potato family crops or tomatoes, capsicum, eggplant for at least four seasons to avoid soil-borne diseases and pests.
When selecting a site, Kariuki advised against poorly drained or rocky soils. He recommended ploughing the land, digging the field thoroughly to remove weeds and break lumps of soil for good air circulation and to allow tubers to grow. Mixing in well-rotted manure and ensuring the soil surface is smooth are also crucial steps in preparing the land for potato farming.
Seed selection is another critical aspect of potato farming. Kariuki emphasized the importance of buying certified seed tubers from agents approved by the Kenya Plant Health Inspectorate Service (Kephis). The seed tubers should have four to five small sprouts growing out.
When planting potatoes, Kariuki advised making furrows 75cm apart and 25cm deep to allow tubers to easily expand and make harvesting easier. He also recommended applying Diammonium phosphate (DAP) at the rate of 200kg per acre at planting, and using Monoammonium Phosphate (MAP) on acidic soils with a pH level of below 5.5.
Management of the crop is also essential. Weeding of the crop starts once the potatoes have grown above the soil, and when the potato plants are between 15 to 25cm tall, heap soil around the roots to give more space for the tubers to grow big and reduce chances of turning green.
Common pests and diseases to watch out for include Early Blight, late blight, brown rot, potato tuber moth, potato leaf rolls virus, and potato viruses. Kariuki advised spraying fungicides on affected crops when you notice the first spots, and for effective control, spray the underside of the leaves.
Harvesting the potatoes is a critical step in the farming process. Kariuki advised harvesting the potatoes when the leaves start to turn yellow, and not leaving mature potato tubers for more than two weeks in the soil to avoid insect attacks and rotting. Before harvesting, the farmer should make sure the skin of tubers has hardened.
According to Kariuki, an acre can produce an average of 7,700kg of potatoes, with a kilo going for Sh27. This means a farmer could earn Sh207,900 in three months, making Irish potato farming a lucrative business in Kenya.
