Quality potato seed tubers are a very important part of any successful crop production. For potato farmers, this is even more important because not all diseases can be eliminated by spraying with chemicals. Few farmers in Africa have access to or can afford certified potato seed. It is therefore important for some potato farmers to know how to produce their own potato seeds on farm. Here are some guidelines:
- Choose the plot carefully
Use virgin land or at least land that has gone for five years without having potatoes, tomatoes, or eggplants. These crops tend to be attacked by the same pests and diseases. Any land that has been limed over the last five years is unsuitable. Avoid water logged areas or areas that get flooded with runoff. Apply plenty of farm yard manure before planting. Ensure that the manure is properly composted. The seed plot has to be 2meters wide and as long as you need it to be. Use a spacing of 30cm by 30 cm and plant at 15 cm deep.
- Use Positive Seed Selection
Inspect the seed plot regularly for any signs of infection or infestation. Quickly remove any plant that infected with bacterial wilt or with viruses. The plants that are healthy during the flowering stage have to be demarcated using pegs or any other marker such as sticks. Continue inspecting the plant every few days for signs of disease or infestation and removing any diseased plants. Plants that are pegged should not be less than 1 meter away from a diseased plant. The plants which are found to be infected with bacterial wilt should be burned – never put them in a compost heap. The plants which are pegged should be harvested first and must never come into contact with the rest. The potato tubers from the pegged plants are the seed that will be used the next season.
- Conduct Weekly Inspection
Inspect the seed plot every week. This allows you to keep an eye on the growth of the crop and to notice any pests and diseases. The pests to look out for are aphids, and potato tuber moths. The diseases to look out for are bacterial wilt, viruses, and blight. Use insecticides on plants that are infested with aphids. Ridge to control potato tuber moth. Bacterial wilt and virus can only be controlled by uprooting and destroying the affected plants. After uprooting the affected plants, insert a handful of lime in the hole. Use fungicides to control blight. The weekly inspection should also be used to weed. Avoid using tools and instead weed by hand.
- Harvesting and Post Harvest Handling
Harvesting should be done carefully so that the tubers are not damaged. When you see leaves start to turn yellow, cut off the stems and then harvest after two weeks. Do not harvest when soil is wet. Select tubers which are 2.5-5.5cm in diameter for use as seed tubers. Anything bigger can be used as a ware potato. Keep the seed tubers in crates and cover with the leaves of lantana camara to keep aphids away. Some of the seed tubers will be used as seed for the next season while others will be used to produce more seed.
- Protect the seed plot
The seed plot must be protected by fencing to restrict movement and lessen the risk of contamination. Consider planting maize around the seed plot to keep aphids off. All farm tools, shoes and feet must be disinfected before entering the seed plot. Dilute household bleach in water to create the cleaning solution.
