When to plant Yam In South Africa
Yam is grown in the warm season.
In the growing season, the plant requires hot days and warm nights and an average summer temperature of 20 °C as it is easily damaged by low temperatures. There must be enough sunlight and very few cold, cloudy days. |
It has a growing season of 3 to 5 months, depending on the cultivar. Planting should preferably take place from October to December, although plantings up to about March can be made in frost-free areas.
Where to plant Yam In South Africa
Yam can be grown on a wide variety of soils. fairly deep sandy loam soil draining well to a depth of at least 50 cm is ideal.
Heavy clayey soils are not recommended as they may produce misshapen roots (tubers) and cause tuber rot.
Very deep soils containing a large amount of organic material are also not suitable, because the plant will have lush top-growth and long, stringy tubers.
For this reason, fresh compost or manure should not be worked into the soil immediately before planting.
Some cultivars such as the yellow Borrie should not be planted in sandy soil, while others such as Ribbok are suited to sandy soils.
Planting Yam In South Africa
Yam is usually propagated by means of rooted shoots or vine cuttings.
It is essential that the material used must be disease-free because the plant is very susceptible to viral diseases.
Rooted shoots
The small-scale farmer can use a few well-shaped, disease-free tubers from his previous crop or buy from the store.
It is expensive to buy from registered nurseries, but their material is guaranteed to be disease-free.
Plant the tubers close together in a seedbed from July to August.
Cover with a 5 cm layer of soil.
When the shoots appear increase watering.
The shoots should be ready (20 to 30 cm long) for planting in 5 to 8 weeks when they are simply pulled off the tubers for planting.
Plant them 30 cm apart on ridges 90 cm apart.
Vine cuttings
If runners or vines are used, cut them into 30 to 40 cm lengths.
Plant the cuttings up to half their length in the soil, 30 cm apart in ridged
rows 90 cm apart.
Press down the soil firmly to ensure that it will grow well.
Plant the cuttings up to half their length in the soil With both methods (rooted shoots and vine cuttings) it is possible to plant the crop successfully on level soil, but a better yield is obtained with flattened ridges.
On sandy soils, the ridges should be 30 cm high and on heavier soils 40 cm high.
Plant the shoots or cuttings 20 to 40 cm apart. The closer the spacing, the smaller the tubers will be.
Water the plants immediately after planting. It is important to keep the soil moist at least until the plants are well established.
It is better to plant crops on the flattened ground
Caring for the plants
Although Yam plants are fairly drought resistant, water them regularly
to ensure a good yield.
Stop watering 2 to 3 weeks before lifting otherwise the tubers may rot.
Pull up weeds regularly, especially while the plants are still young.
As the plants grow, draw up the soil to the main stem to ensure a good yield and to prevent the Yam weevil from reaching the roots through cracks in the soil.
Leaf mottle is caused by a virus. Remove and destroy infected plants.
Leaf spot is usually not very serious.
Using virus-free planting material will usually ensure a good crop.
Draw up the soil to the main stem
Harvesting
The crop can be harvested as soon as the roots are large enough, usually
3 to 5 months after planting, depending on the cultivar.
Usually, the ridges crack open because of the swelling roots.
If the vines are still green, they can be cut off, but not earlier than 2 to 3 weeks before harvesting.
This makes it easier to lift the tubers.
The vines can be used to make new cuttings or as stock feed because they are very nutritious.
Use a garden fork to lift the tubers. Be very careful not to damage them,
because damaged tubers may rot when they are stored or marketed.
If you have a large enough crop to sell, cure the roots by placing the tubers in small heaps on the land for about 7 days to dry off. Cover them lightly with vines to prevent sun damage.
Tubers that cannot be sold or eaten, eg those that are too small or cracked, can be used as stock feed.
Yam does not store very well unless well cured. If you have a small crop, lift only as many as you need every time.
What is the best month to plant yam?
Yam is best planted between February and March in mounds or ridges by planting seed yams (pieces of tubers or completely small ones) preserved for the new planting season.
However, in some localities especially in riverine areas, land preparation, clearing and burning of grasses, heaping, and ridging are done earlier.