MOST indigenous farmers have not been into potato farming, once a preserve of former white farmers, as they lacked production knowledge.
Farmers have mostly produced traditional crops such as maize that are seasonal, resulting in land lying idle in-between seasons.
However, farmers intending to venture into potato production have had to face the hurdle of financial challenges.
Small-scale farmers have since taken up potato production seriously with stakeholders also assisting them through conducting training programmes for new growers.
The private sector has, however, extended support to potato farmers while Government is availing financial support schemes and promoting the use of locally produced seeds.
Through the various schemes, production costs for farmers who have in the past relied on imported seed varieties which are highly priced have been reduced.
Below are some tips on producing potatoes:
Potato plant growth
There are no fixed development stages in potato production as these are influenced by varieties, shoot size, soil fertility and weather.
Unlike rice, potato development stages overlap, making it difficult to distinguish between stages.
For example, sometimes during the early growth stage, developing tubers would have already begun to grow from the roots.
Nevertheless, a division of potato growth stages can provide a picture of the crop’s critical development periods.
This knowledge is extremely important for developing management strategies.
Testing soil to determine fertiliser needs
Fertiliser requirements depend on quantities of nutrients already available in the environment (soil, water and air) and to what extent plants require these nutrients.
If quantities already available are lower than plants’ needs, then fertiliser is applied.
Excessive application can damage plants and waste resources, while applying too little can prevent plants from growing to their optimum size.
Fertiliser requirements
Balanced fertiliser use will produce healthy plants that can resist pests and diseases and compensate for any damage done.
For example, adequate levels of potassium help hardening the cell walls, making them less penetrable to fungal growth.
Healthy potato plants can produce additional cells around a leaf-miner fly egg and hence push it out of the leaf tissue, after which the egg drops to the ground and dies.
Applying fertilisers:
l Plants’ nutrient requirements in relation to estimated yield.
l Quantities of nutrients in the field available for plants
A. Organic fertiliser
l Apply at planting time by mixing it straight into the soil or by placing it to the left and right of the seeds.
l Organic fertiliser requirements for potato crops are minimally 20 tonnes a hectare (ha).
B. Nitrogen
l Is particularly needed during the vegetative growth and tuber initiation stages.
l Nitrogen is very soluble and volatile, so is best applied in split application.
Avoid applying it when fields are flooded or there is water flowing on the surface of the soil.
Nitrogen evaporates easily, so should be covered over by soil immediately after application.
l It is best to do two or three applications, applying 25 percent at planting and 75 percent at 30 to 35 days after planting, by putting it 10-20cm deep into the soil.
l To save energy and expense, you can apply nitrogen fertiliser at the same time as weeding and hilling up.
C. Phosphorus (P)
l Required during the vegetative growth and tuber bulking stages.
l P fertiliser takes time to release its P content into a form readily available for plants to absorb.
It bonds easily to minerals in the soil.
l It is best to apply it at planting time as basal application.
l Soils in mountainous areas generally contain natural P, so they need little P content fertiliser.
D. Potassium (K)
l Is essential during the tuber bulking stage.
l K fertiliser releases its K content in a form available for plants.
l K fertiliser is applied once at 30 to 35 days after planting.
l K easily dissolves in water and should therefore be covered by soil after application.
Planting materials and method:
How to plant:
l Mini tubers – Plant mini-tubers with a spacing of 20cm by 20cm at a depth of five-to-10cm into the media.
l Tissue culture plantlets – Pull up tissue culture plantlets and clean their roots.
You must do this carefully to prevent roots and stems from breaking. Then plant them with a spacing of 10cm by 10cm.
Plant care
Plants are tended while they are growing by removing those plant parts damaged by pests and disease, as well as loosening media, applying fertiliser and watering.
Taking cuttings for propagation
When seed material is growing well, take stem cuttings for propagation at about eight to 15 days after planting.
These stem cuttings, taken from parent stock plants, should be about 3-to-4cm long, be dipped in a solution of a root growth stimulating chemical and planted in different trays with plant spacing of 20cm by 20cm.
Harvesting
Harvesting takes place at 75 days after planting, or when the plants start to die.
Do this by dismantling the soil around the plants.
One plant typically produces two to four tubers, each weighing 10 to 20g.
Select tubers based on their size and then store them.
The tubers can be used for seed to plant in the fields or propagated in a screen house to produce the next generation of seed tubers.
Additional information www.vegetableipmasia.org