2007 - Potatoes at WSU - Washington State University

• On average, ID- and WA-grown tubers produced the lightest fry colors at harvest. When stored
at 48 o F, the processing quality of ID-grown tubers improved, while tubers from WA and OR lost
quality, characterizing a significant effect of production site on storability. Averaged across the
three production sites, the Regional clones retained 87% and 70% of their processing quality
(stem end) when stored at 48 and 44 o F for 44 days, respectively.
LRT
• Fry colors were non-uniform from bud to stem end for many of the OR-grown clones prior to
and after storage, regardless of storage temperature. The uniformity of fry color progressively
worsened for WA and ID-grown tubers with falling storage temperature. The incidence of jelly
end rot was higher than normal this season. AOA95155-7, AOA95154-1, and RR varied the
most in their ability to retain processing quality during storage for 44 days at 44 o F, as affected by
production site.
• Similar to the results in 2005 and 2006, AOA95155-7 was highly resistant to blackspot, with only
6.9% of impacts showing bruise (3-state average). AO96141-3 also showed bruise resistance
(17% bruise). In contrast, RR, TXA549-1Ru, A95409-1, and AC96052-1Ru had 85, 81, 61, and
57% of impacts developing bruise, respectively. Bruise severity was greatest in RR (3.7/5) and
TXA549-1Ru (3.4/5) and least in AOA95155-7 (1.2/5) and AO96141-3 (1.3/5).
• On average, ID-grown tubers had the highest L/W ratios (2.1) compared with those grown in WA
(1.7) and OR (1.7). TXA549-1Ru and AC96052-1Ru had the lowest L/W ratios (average=1.54),
reflecting round tubers. TXA549-1Ru also had the lowest L/W ratio last year. AO96141-3, RR,
RB, and AOTX95265-3Ru had the highest L/W ratios (2.0-2.1). AOA95155-7 and AO96164-1
had the greatest variation in L/W ratio of 8- to 10-oz tubers across states. In contrast, the L/W
ratios of RB, AOTX95265-3Ru, AO96141-3, and TXA549-1Ru were least affected by growing
location. The results are consistent with last year for the latter two clones.
• A95409-1, AO96141-3, AO96164-1, AOA95155-7 and TXA549-1Ru produced the longest sprouts
after 7 months of storage, considerably longer than either check (Ranger or Russet Burbank),
indicating relatively short dormancy.
Overall Regional Postharvest Merit Scores
Postharvest M erit Scores
3 state
C lone W A ID O R Average
7 AO 96141-3 4.4 4.1 4.4 4.3
8 AO 96164-1 4.7 3.5 4.4 4.2
12 C O 97087-2R u 4.6 3.8 3.7 4.0
9 AO A95154-1 4.0 4.4 3.7 4.0
6 AC96052-1R u 4.4 4.0 3.6 4.0
5 A97287-6 4.6 3.8 3.3 3.9
4 A96104-2 4.1 4.5 2.4 3.7
10 AO A95155-7 3.7 4.2 2.6 3.5
1 R anger R usset 3.2 4.1 2.8 3.4
13 TXA549-1R u 2.9 4.2 2.2 3.1
3 A95409-1 3.0 3.5 2.6 3.0
2 R usset Burbank 2.9 2.3 1.3 2.2
11 AO TX95265-3R u 2.3 2.3 1.1 1.9
2007 Potato Cultivar Evaluations 85 WSU Potato Research Group