1. I'm going to try to get ahold of the presenters at the
ASA/CSSA/SSSA meeting that Benbrook attended, to get a better handle
on the research which they've already done to support the reported
comments on OP vs. hybrid corn. I'd suspect that they have already
done a lot, and probably have published it, and if so, that may be
enough to settle our little "sanet-wager" without further field work
needed.
2. People may want to proceed with this comparative planting on
their own - and to this I say GREAT! - but if friend Dale is at all
serious about publishing the results, I'm sure he'll want to ensure
publishable trials. And I mean trials, because to make a meaningful,
publishable paper would require several site years of replicated
trials on sites strategically chosen and managed to address specific,
worthwhile questions. This is partly the plain and simple truth
regarding publishability in refereed journals, but more to the point,
it is essential to address the central question of the robustness of
the genetics across environments, or in other words, the potential
for genotype x environment interaction (GxE).
3. How stable or robust is a contemporary hybrid vs. an OP cultivar,
across a range of environments, growing conditions, etc. within their
own heat unit zone? How well will they tolerate a droughty spring,
an infestation of whatever, a cold wet spring that delays herbicide
application? To answer this honestly, you need to select enough
sites to capture a range of representative conditions, and then do
it for enough years to "catch" dry summers, wet springs, late falls,
or whatever else you think will stretch/test the robustness of the
corn. Enough sites (e.g. mgt regimes/soil constraints) and years
(e.g. environments) will give credibility to the findings and create
a zone of inference big enough to encompass the likely range of
environments in which corn is grown in your area.
4. Doing this "right" is partly large plots, fair enough, and
replication - certainly - as well as sound statistical and managerial
design. But it is mostly sites and years. I say this not to
discourage anyone, but to be up front about what is needed to do this
properly. Not just for publication, but to really answer the
question.
5. If you want to try it for a year at one location, fair enough,
but be clear about the "zone of inference" or generalizability of
your data. You will be able to say what happened in that single
year, and under those single conditions - whatever they were - but
will not be able to generalize to other years or sites.
6. And as far as "yield" goes - I'm much more interested in profit
than yield, for reasons well discussed by others on this list
already.
So - as soon as I've reached the original speakers referenced by
Benbrook, I'll report back to the list - or perhaps get them to do it
for us. Ann
ACLARK@plant.uoguelph.ca
Dr. E. Ann Clark
Associate Professor
Crop Science
University of Guelph
Guelph, ON N1G 2W1
Phone: 519-824-4120 Ext. 2508
FAX: 519 763-8933
http://www.oac.uoguelph.ca/www/CRSC/faculty/eac.htm
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