iv
WHEAT VARIETIES, TECHNOLOGY, CLIMATE & YIELD: AN ANALYSIS
USING WSU’S WHEAT VA
RIETY TEST DATA AND
INTERPOLATED WEATHER RECORDS
ABSTRACT
by Joel Thomas Michalski, Ph.D.
Washington State University
May
2012
Chair: Vicki McCracken
Data from the WSU wheat variety test program along with spatially interpolated
historic weather
records present a unique opportunity to compare wheat variety
performance across time and Washington State geography. A key assumption in this
analysis takes wheat variety to be genetically constant year
-
over
-
year. This assumption
allows us to separate bre
eding versus farm
-
level productivity gains. Furthermore, across
the wide variety of climate regions within Washington State, productivity gains can be
measured for different climate regions, allowing a unique contribution to the body of
literature attempti
ng to differentiate the various technology contributions to farm
productivity.
Analysis of breeder contributions to wheat productivity gains are then applied to
state
-
wide USDA productivity data and determine the economic benefit provided by the
wheat vari
ety improvements to average $1.8M per year (2010 dollars).
Finally, a close analysis of wheat variety response to moisture is combined with
results from ten global circulation models to make long
-
range predictions on Washington
v
State wheat productivity for
the 30 year average 2020
-
2050, expecting wheat growing
regions in Eastern Washington to remain consistent with current trends while the East
Central agriculture district will see modest gains compared to the other