2001 Late Harvest Tri-State Evaluations
The Late Tri-State Trial is a component of the Tri-State cooperative project involving Washington, Oregon and Idaho. Entries for the Tri-State trials are chosen by the Tri-State committee. All entries in the trials are grown in each of the three states to determine how they perform when grown under different management and climatic growing conditions. This year the trial had two cultivars and eleven clones; nine of the clones were also in the Early Tri-State trial. The following summarizes the Washington field results along with postharvest results from all three locations.
The postharvest evaluations are intended to identify those clones acceptable to the French fry processing industry. Samples are obtained from the Washington (WA), Idaho(ID) and Oregon(OR) field adaptation trials for analysis in Pullman.
Nine clones and two cultivars were tested from each growing location. A92030-4 from OR was a variety mix of smooth-skinned and russeted potatoes in equal proportion. Also note that Ranger and Russet Burbank from OR have the same values in the Tri-State and Regional Trials for all evaluations except the taste panel, due to limited sample.
The three highest scoring clones across states were A91814-5, A93157-6LS and A9305-10. These clones produced the lightest colored fries following 55 days storage at 44 and 40°F, indicating resistance to low-temperature sweetening (LTS). Region of production affected the ability of these clones to maintain at-harvest processing quality during storage. In general, ID-grown tubers retained more of their at-harvest processing quality than those grown in OR, which in turn retained more than those grown in WA. While these three clones showed the highest resistance to LTS, they also showed the highest variability in retention of at-harvest processing quality during storage at 44°F when assessed relative to the other clones across the tristate production sites.
PA95A11-14 and A93116-3 were the two lowest scoring numbered clones. On average, both clones produced darker colored fries at harvest. PA95A11-14 came from the field with stem end sugars at harvest and, along with A93116-3, showed little resistance to LTS through the storage season. It also received the lowest ‘taste’ rating in all taste panel evaluations.
Despite its propensity to sweeten in storage, A93116-3 was one of the most resistant clones to blackspot bruise and soft rot susceptibility.
The wound healing abilities of A92030-5, A93116-3, A91814-5 and A9305-10 were significantly better than that of PA95A11-14 and A93157-6LS.
The 8 to 10 oz tubers of A91814-5 had a relatively low length to width (L/W) ratio of 1.38, indicating a rounder shape, and thus the estimated yield of French fries 3 inches in length (by number) from these tubers was only 57%. Yield of fries from 8 to 10 oz tubers of A93157-6LS, PA95A11-14, A93116-3 and A9305-10 averaged 70%. A92030-4 (variety mix in OR), PA95A11-14, A93157-6LS and A9305-10 had the greatest variation in tuber shape and thus fry yield across the tristate production sites.