v120102 (c) 2002-03, RLNielsen, Purdue Univ. 1 Selecting Hybrids Wisely Bob Nielsen Purdue University Email: [email protected]Web: www.kingcorn.org (c) 2002 -03, RLNielsen, Purdue Univ. 2 v120102 Corn is a GMO! n Genetic modification of corn has been occurring for thousands of years. n Center of origin = Mexico, central America n Earliest plant breeders = women n Genetic modification the old-fashioned way: Hard work! n Now, genetic modification is possible using fancier tools than ever before. n Including the transfer of genes from other living species into corn. First of all, let’s admit that… (c) 2002 -03, RLNielsen, Purdue Univ. 3 v120102 Perfect hybrids do not exist! n Else there wouldn’t be so many hybrids for sale in the marketplace n Corn’s genetic yield potential is great! n Physiological est’s as high as 600 bu/ac n Francis Childs, IA, 500+ bu/ac n Harvested yield is influenced by many factors n Disease, insects, weeds, fertility, your management, soils, weather n Genetics interacts with most of these factors (c) 2002 -03, RLNielsen, Purdue Univ. 4 v120102 How to choose hybrids wisely? n Commercial advertising? n Radio, TV, magazines, newspapers n Sales literature? n Sales pitches from seed dealer? n Testimonials? n Comparative yield performance data n My personal favorite (c) 2002 -03, RLNielsen, Purdue Univ. 5 v120102 Yield performance data n Many possible sources: n Seed company summaries n Yield contest summaries n County test plots n Your test plots n University trials (c) 2002 -03, RLNielsen, Purdue Univ. 6 v120102 Seed company summaries n Number of test locations can be quite large (a strong advantage ) n Comparisons with competitor hybrids often limited in number (no surprise ) n Tend to favor their hybrids over competitors (no surprise ) n Are probably the best information source for that particular company’s hybrids ( makes sense ) n Side-by-side comparisons commonly used technique (has limitations)
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n Genetic modification of corn has been occurring for thousands of years.n Center of origin = Mexico, central America
n Earliest plant breeders = womenn Genetic modification the old-fashioned way:
Hard work!
n Now, genetic modification is possible using fancier tools than ever before.n Including the transfer of genes from
other living species into corn.
First of all, let’s admit that…First of all, let’s admit that…
(c) 2002 -03, RLNielsen, Purdue Univ. 3v120102
Perfect hybrids do not exist!n Else there wouldn’t be so many hybrids for
sale in the marketplacen Corn’s genetic yield potential is great!
n Physiological est’s as high as 600 bu/acn Francis Childs, IA, 500+ bu/ac
n Harvested yield is influenced by many factorsn Disease, insects, weeds, fertility, your
management, soils, weather
n Genetics interacts with most of these factors
(c) 2002 -03, RLNielsen, Purdue Univ. 4v120102
How to choose hybrids wisely?
n Commercial advertising?n Radio, TV, magazines, newspapers
n Sales literature?n Sales pitches from seed dealer?n Testimonials?n Comparative yield performance datan My personal favorite
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Yield performance datan Many possible sources:n Seed company summariesn Yield contest summariesn County test plotsn Your test plotsn University trials
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Seed company summariesn Number of test locations
can be quite large (a strong advantage)
n Comparisons with competitor hybrids often limited in number (no surprise)
n Tend to favor their hybrids over competitors (no surprise)
n Are probably the best information source for that particular company’s hybrids (makes sense )
n Side-by-side comparisons commonly used technique (has limitations)
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Yield contest summariesn Farmers “win” with a particular hybrid
and set of management practices.n Such contests are not meant for
comparative hybrid performance.n How often a hybrid is associated with
winning contest yields can be influenced by how actively the seed company promotes the hybrid among contestants.
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County test plotsn The number of test locations is usually
limited to a small no. within the county.n Hybrid entries are often chosen by local
sales reps.n Hybrid entries are often not repeated
more than one year.n Number of companies represented can
range from few to many.
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Your test plotsn Number of test locations = 1n Number of hybrid entries often limitedn Hybrids entered into test are some
combination of your choices and seed rep’s recommendations
n Perception of value to testing on YOUR soils using YOUR management practices
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University trialsn No vested interest in which hybrids winn No. of locations typically fewer than those in
seed co. trials, but more than county trials.n No. of companies in trial is typically quite large
n No. of hybrids per company per zone usually smalln Hybrids entered into trials are usually the choice of
the seed company
n Multi-year hybrid data are usually availablePurdue Variety Trials:
http://www.agry.purdue.edu/ext/variety.htm
Purdue Variety Trials:
http://www.agry.purdue.edu/ext/variety.htm
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Bottom line?n There is no single method that is easy
or perfect for selecting corn hybrids that will perform consistently well in your farming operation.
n Choosing hybrids wisely requires a lot of searching for yield data and a lot of homework “massaging” the data to make sense out of it.
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Dumb hybrid decision-making n Simply because it’s cheap.n Simply because it’s new.n Simply because it’s biotech.n Simply because it’s the one the company has
the most bags of in the warehouse.n Simply because it’s genetically different from
the other one you bought.n Simply because you trust the seed rep.
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Smart hybrid decision-makingn Look for hybrids that yield consistently
well across a diverse set of conditions, especially weather and disease.n That is to say, you are looking for hybrids
with high yield and low G x E.
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What is G x E ????n Genotype by Environment
n Describes the common fact that hybrids (genotypes) often respond (or interact) differently to different environments n Soils, n Diseases, n Insects, n Fertility,
n and especially weather
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G x E illustrated…
0
50
100
150
200
250
80 100 120 140 160 180 200 220
Yield environment
Hyb
rid
yie
ld
Hybrids often respond differently to yield influencing factors.
Four hypothetical hybrids
Which hybrid would you want?Which hybrid would you want?
n Not enough data to predict stability of hybrid performance across a range of growing conditions.nThis is why you should not place a lot of
faith in the ability of your own on-farm testing to predict a hybrid’s yielding ability in the future.
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Avoid … n Side-by-side comparisons, unless they are
between pairs of hybrids you’ve already identified as being top yielders.
n In other words, just because my hybrid outyields your hybrid in 12,089 side-by-side comparisons across 10 states, does not mean that either hybrid is the best performer in the marketplace!
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Avoid … n Hybrids without documented comparative
yield performance data over multiple locationsn Don’t buy on advertising or price alone!
n “Percent wins against the competition”n The “competition” is often a “bunch” of
unidentified hybrids that could be “dogs” for all you know.
n What you need to know is the “percent wins” against the BEST of the competition!
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Specialty Trait Hybrids…n Often more complex to evaluate than
normal hybrids. You need to know…n Performance compared to other hybrids
with similar trait, if others exist.nGrain yield, output trait “yield” or quality,
and other important characteristics.n Finding comparative data in public or
private trial reports may be difficult.
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Also should determine…n Performance compared to the best
“normal” hybrids in the marketplace.n Yield & other important characteristics relative
to economics of adopting specialty trait versus “normal” no. 2 yellow dent hybrids.
n Comparison to “normal” version of same hybrid not as important.
n Finding comparative data in public or private trial reports may be difficult.
Specialty Trait Hybrids:Specialty Trait Hybrids:
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Comparison to “normals”n Compare the best specialty hybrids in a
trial with the best normal hybrids.n University trials work well for this, assuming
that companies enter the best hybrids of these traits in the trials.
n This strategy is useful for comparing…nBt vs. non-Bt hybridsnRR vs. non-RR hybridsnWaxy vs. normal starch hybrids
Comparing Specialty Hybrids w/ Normal Hybrids:Comparing Specialty Hybrids w/ Normal Hybrids:
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Yield Comparisons of Top 5 non-Bt and Bt Hybrids Purdue Corn Performance Trials, 1999
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Non-BtBt
Non-Bt 153 202 213 143 191 200
Bt 149 202 204 139 192 194
North-Hi Central-Hi South-Hi North Central South
Average yield difference for Bt hybrids = - 2 . 0 %Average yield difference for Bt hybrids = - 2 . 0 %
Example of Best vs. Best Strategy:Example of Best vs. Best Strategy:
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Yield Comparisons of Top 5 non-Bt and Bt Hybrids Purdue Corn Performance Trials, 2000
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200
250
Non-BtBt
Non-Bt 153 207 203 157 202 201
Bt 141 189 198 142 186 189
North-Hi Central-Hi South-Hi North Central South
1/
1/ South trial = Average of 3 hybrids only.
Average yield difference for Bt hybrids = - 7 . 1 %Average yield difference for Bt hybrids = - 7 . 1 %
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Yield Comparisons of Top 5 non-Bt and Bt Hybrids Purdue Corn Performance Trials, 2002
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140
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180
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Non-BtBt
Non-Bt 166 158 188 183 174 130 149 147
Bt 154 153 179 178 174 119 131 143
South early South lateCentral
earlyCentral midCentral late North early North mid North late
1/
1/ Northern early maturity trial = Average of 4 hybrids only.
Average yield difference for Bt hybrids = - 5 . 1 %Average yield difference for Bt hybrids = - 5 . 1 %
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Wise hybrid selection…n Requires a lot of research & homework.n Can be challenging because multiple location
performance data are often difficult to obtain. n Can be challenging because performance data
often require further analysis & scrutiny.n Can improve net profits due to higher and