2007 - Potatoes at WSU - Washington State University

Process Value - Methods
Early Harvest
Economic Potential
The gross return in U.S. dollars per acre for each trial entry was calculated using an early-harvest
mock processing contract similar to those used by Washington State processors. All assumptions
are listed below.
Contract Assumptions:
1. Base price of $102/ton.
a. Base price is an average of early-harvest Ranger Russet contracts from Washington
processors based on an August 1, 2007 harvest date.
2. Market Yield (U.S. #1s & 2s) of tubers greater than 4 oz, was multiplied by the base price.
3. Undersized market-grade potatoes less than 4 oz (process culls) were valued at $40/ton.
4. Specific gravity reject level for Ranger Russet contract = 1.074.
5. No premiums and penalties were applied for tuber fry color, sugar content, internal defects, or
bruise.
Late Harvest
Economic Potential
The gross return in U.S. dollars per acre for each trial entry was calculated using a late-harvest mock
processing contract. Process-market values are based on criteria (below) similar to that used by WA
potato processors. Production costs per acre were not applied. Direct delivery contract assumptions
are listed below.
Contract Assumptions:
1. Base price per ton was $77 for market (U.S. #1 & 2) grade tubers.
2. Premiums for 6 oz and larger market grade tubers of $0.60/ton for each percentage point
greater than 50% they contribute to the total tuber yield composite, up to 70%, with a maximum
of $12.00/ton. Penalties were $0.60/ton for each percentage point below 50%. Below 48%,
penalties were $1.20/ton with no rejection minimum.
3. Penalty for 12 oz and larger market grade tubers of $0.60/ton for each percentage point greater
than 35% they contribute to the total yield composite, with no rejection minimum.
4. Premiums for average tuber specific gravity values above, and penalties for values below, 1.076.
Premium per CWT is $0.05 at 1.077, $0.20 at 1.078, $0.30 at 1.079, $0.40 at 1.080, $0.50 at
1.081, $0.60 at 1.082, $0.70 at 1.083, with a maximum of $0.70 for 1.084 through 1.088. Above
1.088 the premiums drop: $0.65 at 1.089, $0.60 at 1.090, $0.55 at 1.091, $0.45 at 1.092, $0.35
at 1.093, $0.25 at 1.094, $0.15 at 1.095. Above 1.096 penalty of $0.15/CWT. No premium or
penalty for 1.076, $0.50 penalty at 1.075, for each 0.001-point decline from 1.075, lots were
penalized $1.00/CWT with no rejection minimum.
5. Premium of $0.03 for each percentage of bruise-free tubers above 54% of total yield, up to a
maximum of $0.75 for > 79% bruise free tubers; Below 54%, no premium or penalty.
6. Undersized market grade potatoes less than 4 oz (process culls) were valued at $40.00/ton.
7. No premiums or penalties were applied for tuber fry color, sugar content, or internal defects.
2007 Potato Cultivar Evaluations 5 WSU Potato Research Group