2000 Late Harvest Regional Trial Evaluations
The postharvest evaluations are aimed at identifying clones from the Regional Cultivar Improvement Trials that are best suited for the Pacific Northwest potato industry. Tubers grown as part of the Washington, Idaho and Oregon cultural adaptation portions of these programs are evaluated for processing quality and storability at the potato Postharvest Research Laboratory, WSU, Pullman. Industry input has helped to create the current rating system, which is continually being revised based on industry needs and priorities.
A9014-2 and ATX9202-3Ru produced the lightest and most uniformly colored fries when processed directly out of the field as compared with the other seven entries. The former clone, A9014-2, received the highest and second highest overall rating scores of all clones in the 1999 Regional and 1998 Tri-State Trials, respectively. It outperformed all other entries in this years Regional Trial and actually received bonus points giving it more than the maximum possible rating of 35 when grown in ID. A9014-2, as well as Russet Burbank, Ranger and AC87138-4 showed the least variation in tuber shape and fry yield across the tri-state production sites. Despite the fact that A9014-2 has a relatively low L/W ratio and fry yield its ability to resist variation in morphology and thus maintain consistent shape across diverse growing regions makes it well suited to production in the tri-state area. A9014-2 also showed significant resistance to sugar accumulation when stored at both 40 and 44°F.
ATX9202-3Ru received the second highest overall postharvest rating, with a three-state average of 27.
A8792-1 tubers had the highest specific gravity relative to that of the other entries at harvest.
The darkest colored fries at harvest were produced by A90586-11. Last years trials also showed this clone to darken appreciably during storage.
Of the numbered clones, AC87138-4 received the lowest three-state average postharvest score of 16.4. When averaged across the tri-state area, all clones rated higher than Russet Burbank in processing and culinary qualities during storage.
The French fry taste panel scored A9045-7, A90586-11 and AC87138-4 the lowest in culinary quality. AC87138-4 had more hollow heart/brown center than the other clones. The four remaining numbered clones scored as high or higher than the standards in culinary fry quality. As in past evaluations, bruise potential was greater on the stem ends of all entries. No clear differences in bruise susceptibility among clones across growing location were evident.
All numbered clones in the Regional Trial produced tubers with lower length/width ratios than Ranger or Russet Burbank from their same growing location and when averaged across location, resulting in 4 to 10% lower estimated fry yields, depending on the clone. These trends were consistent for all of the clones produced in WA, ID and OR.