Q : I am a small farmer in Meru growing potatoes. I have heard that Yara has good fertilisers for potatoes, please advise me on how to grow and get good harvest from the crop.
Like many crops, starting with the right seed is important, and is probably even more crucial for potatoes to use clean, certified planting materials.
The seed must also be at the right physiological stage with at least 4-5 sprouted eyes.
All other agronomic practices such as weed, pest and disease management have to be adhered to as well.
Fertilisation of potatoes
Application of fertilisers that supply balanced nutrients for potatoes, giving both primary, secondary and micro-nutrients is critical for high yields and quality potatoes.
Critical to remember in potatoes is that the peak nutrients uptake for most varieties is between 30-35 days after germination.
This mean that all fertilisers need to be applied not later than five weeks after germination.
Influencing yield and quality
Application of an NPK fertiliser with an adequate supply of phosphorous such as UNIK 17 is critical at the planting stage.
This is so because phosphorous is an important element in determining, especially the tuber numbers (besides the variety type) and this is signalled early in the growing stages for potatoes.
The nitrogen and potassium are critical in supporting early crop establishment.
A topdresser with a good NPK with a relatively high amounts of potassium like YaraMila WINNER at tuber initiation stage (2-3 weeks after germination) and a supply of soluble calcium at this stage are critical.
This is so because the potassium and nitrogen supplied is good for canopy development, accumulating enough biomass to support vigorous growth and especially bulking of the tubers to produce large tubers.
Potassium also helps enhance the potato crop’s tolerance to moisture stress.
Calcium is critical in developing a tough skin and prevent bruising and cracking of the potato tubers, as well as reduces incidences of tuber diseases such as Erwinia Soft Rots.
Other agronomic practices
Potatoes are sensitive to diseases such and blights which also thrive under the wet cold climates adapted for potato production.
It is, therefore, important to maintain a regular preventive spray programme against blights and other pests.
Hilling/ earthing up is an important practice to also allow for good tuber expansion and avoid physiological disorders like greening of the tubers.
In short, therefore, a good fertilisation regime applied at the right time, as well as other agronomic practices will give you good yields and good quality tubers.
For crop specific fertiliser recommendations, please consult the following agronomists in your area:
Central Region: Stephen Mburu, 0728396204.
Upper Rift Valley: Daniel Mui 0702466343.
Eastern: Dennis Nyandaya, 0702466372.
Lower Rift Valley: Chris Masira, 0798498320.
Western: Eric Okwado, 0715484224.
Vitalis Wafula, East Africa Regional Agronomist, Yara.