Harvesting Orange-Fleshed Sweet Potatoes: Yields, Soils, and Pests

This week Trax field staff are visiting farmers to observe the harvesting of orange-fleshed sweet potato and weigh the yield. For many of the farmers this was the first time they had grown this variety of sweet potato. Field staff have made some important observations about the growth of the potatoes.

Cultivation of orange-fleshed sweet potatoes (OFSP) was introduced to 50 of Trax’s beneficiary farmers during a pilot last year and expanded to 100 farmers this year. The OFSP is an improved variety that has been introduced to farmers because it grows faster than the native variety so it can still yield well in years when there is drought. This OFSP variety also has higher Vitamin A content than other sweet potato varieties so it is good for reducing Vitamin A deficiency in children which is widespread in Ghana. You can read more about Trax’s OFSP project here.

This farmer has been caring for her OFSP crops while pregnant. Here she is seen with her baby and harvested OFSP. OFSP can support child nutrition due to high Vitamin A content.

The OFSP yields have been good despite the drought at the start of this season because it will grow in a shorter period of time.

Two farmers sort their orange-fleshed sweet potato yield by size

There are differences between the OFSP and the native variety of sweet potato. Some of the native potatoes are much smaller than the OFSP, while others are larger but take longer to grow.

Left image: A farmer displays a small native variety of sweet potato. Right image: OFSP (left) are seen next to a large native variety (right).

 Soils and Weevils Affect OFSP Yield

While visiting different farms to weigh the yield after harvesting the OFSP, Trax field staff observed that there was a pattern in the farms which had particularly high yields. The highest OFSP yields were observed on farms which had a very sandy soil type. Sweet potatoes grow best in a loose soil so that the root can expand, so a sandy loam is good for cultivating sweet potato. Soils in the areas where Trax are working are typically sandy loams but some areas are much sandier than others. The difference in OFSP yield in the different soil types has been very obvious while observing the harvesting.

It also appeared that the presence of the sweet potato weevil, the main pest of OFSP, was higher in the less sandy soils. It is important that the OFSP is harvested as soon as it is ready so that it is not at risk of being spoiled by weevils. On some farms there was already evidence of the weevils damaging the crop.

Evidence of pests damaging the crop – sweet potato weevils have been eating this potato

Despite some presence of pests farmers were very happy with their orange-fleshed sweet potato yield. You can see more photos of the OFSP harvesting on our Facebook gallery here.