Research Report: Sweetpotato early harvest study, 2014

In NH, sweetpotato is typically harvested in late September or early October. To ensure good eating quality, roots must be stored for a brief period (a good guideline is 3 weeks) prior to consumption. During this time, starches in the roots convert to sugars, which can be measured by an increase on soluble solids (brix). Some growers are interested in selling sweetpotatoes in early fall markets (mid- to late-September), which would require harvest 3 weeks prior to the intended sales date. In direct response to questions posed by growers, we designed an experiment to evaluate yields and soluble solids of early-harvested roots compared to roots harvested in late fall.

Our objective was to compare yields and changes in soluble solids and dry matter of ‘Covington’ sweetpotato harvested at four different dates (21 August through 29 September).  Overall, we found that early harvested roots had the same quality as late harvest roots, but that that harvesting early is only desirable if there are large market advantages to selling early, since a significant yield reduction can be expected. Access the full report for more details.


Rebecca Sideman
Sustainable Horticulture State Specialist
Full Extension State Spec/Prof
Phone: (603) 862-3203
Office: Agriculture, Nutrition & Food Systems, Kendall Hall Room 316, Durham, NH 03824