By Joshua Kato
How to propagate the plant
Farmers can propagate sweet potatoes as vegetative using stem segments called vines.
These are taken from the top of the old stems and caution should be taken to avoid chloric, mottled, wrinkled or vines with mosaic patterns. Plants with mosaic patterns could most likely be having a viral disease.
Farmers can practice rapid multiplication practices to multiply vines.
Here you use two-node cuttings, make a bed spacing of 2cm apart, apply aerial fertilizer and in two months the planting material will be ready for planting.
Farmers can also use the conventional method by cutting vines and planting them in a nursery. Once they have grown 30cm, it is ready for planting.
Planting sweet potatoes
Sweet potato is either planted in mounds or on ridges using vine cuttings.
Vines are mature stems and are taken from the shoot. A good vine cutting should be about one foot long or about six nodes and should be disease free.
When mounds are used, they should not exceed a height of 1m in height and diameter. The size of the mound, however, varies with the type of soil. In soils that are prone to drying, small mounds are used; big mounds in such a case are overexposed to sunshine and they dry out very fast.
The number of vines used varies, as small mounds will take few vines and the big mounds accommodate more vines.
Planting is mostly done by hand, but you can plant sweet potatoes using forked sticks in some cases.
Vines for planting should be picked and allowed to wilt in the shade to ensure that the vines do not break during planting as fresh vines are brittle. These vines also root easily and ensure faster establishment of the crop in the soil.
Sweet potatoes should be kept weed free in the first months and this is done by weeding around the ridges/mounds. Weeding is normally done by hand.
After about two months, the canopy of the crop is normally big enough to cover the ground and this helps to keep away weeds.
It is important to cover cracks arising from the growth of the tubers with soil, otherwise if left open will attract weevils that will infect the tuber.
Harvesting and postharvest handling
To harvest, you can use a hoe or digging fork to gently remove the soil from the ridges or mounds when digging up your ridges and mounds during harvest, start at the top following the stem and roots of the vine.
You will find the sweet potato tuber along the roots just under the vine stems.