It is recommended to dig out a sample of roots from the field about three weeks before expected harvest date, in order to examine the yield and quality of the produce.
In order to facilitate digging, the foliage should be removed before harvest. Utmost care must be taken during digging and collecting the roots, in order to prevent damage, especially abrasions and broken tips, and maintain the highest possible quality. The sweet potatoes field boxes should be washed with clean water (preferably, if possible, while still in the field) in order to get rid of most of the soil before transporting the boxes to the packing house.
If the sweet potatoes are intended for long-term storage or for export, they should be cured. During the curing process the root skin will heal bruises and other mechanical damages caused during harvest. For the curing process to proceed, the sweet potatoes are held for several days at high temperature and air humidity. Following curing, sweet potatoes can be stored in boxes at 12 degrees centigrade and high air humidity.
Grading of sweet potatoes is carried out according to the intended market requirements. They can be sized to different sizes and graded to several quality classes. Grading produce for demanding markets is usually done by mechanized grading lines, using specific criteria of size and quality. Packaging for European markets is done in 6 kg cardboard boxes, each size packed separately. Advanced grading lines for sweet potatoes include washing and drying facilities, automatic weight-sizer that separate the roots into predetermined size-fractions, and packaging tables where manual grading takes place before final packaging in cartons