An Economic Analysis of the Effects of Harvest Timing on Yield, Quality, and Processing Contract Price for three Potato Varieties

Harvesting potatoes at or near physiological maturity increases the likelihood of producing high quality tubers which contributes to producing high quality processed end-product. Some growers harvest earlier than recommended in order to meet contract requirements and supply processors with early potatoes. Early harvest impacts the incentive-adjusted price (IAP) and revenue even after an early harvest incentive is applied. This study utilized a typical frozen processor contract and compared the economic impact of harvest timing (early, normal, and late) on the IAP of three potato varieties: Russet Burbank, Clearwater Russet, and Alpine Russet, grown in field trials at Parma, Idaho during 2014 and 2015. Contract quality incentives included percent of tubers greater than 170 g, percent sugar ends, percent of U.S. No. 1’s, and specific gravity. When compared to normal or late harvest, early harvest resulted in a decrease in the IAP and overall profit due to a significant reduction in specific gravity. Early harvest incentive did not offset the loss of revenue with Russet Burbank, but did offset revenue loss with Clearwater Russet and Alpine Russet. Clearwater Russet and Alpine Russet had significantly lower sugar end scores than Russet Burbank. Clearwater Russet consistently produced higher specific gravities and Alpine Russet produced larger tubers compared to Russet Burbank. Clearwater Russet and Alpine Russet have agronomic characteristics that can provide an increase in IAP over Russet Burbank.