From: Wilson, Dale <WILSONDO@phibred.com>
To: 'E. Ann Clark, Associate Professor' <firstname.lastname@example.org>;
Date: Thursday, October 29, 1998 11:50 AM
Subject: RE: open pollinated corn
>> 1. Let the results be expressed as NET economic returns
>I think we should explore all possible ways to express the results, but
>Chucks statement and my challenge had to do with yield.
>> let's make his hybrid a GE hybrid
>Let's let Pioneer sales agronomists pick the exact hybrid, but to keep this
>simple, let's use one hybrid, and one OP.
>> 2. Let each crop (hybrid and OP) be grown under optimal conditions -
>> for IT - which may not be the same - and let the input costs vary
>Trouble is, that would confound the results, and make it much harder to lay
>out the plots in a reasonable experimental design. As a compromise, I
>propose a 2 x 2 factorial experiment conducted as a split plot. Management
>would be the main plot factor, either Best-management-practices (BMP) for
>the OP or BMP for the hybrid. Variety (OP vs hybrid) would be the sub-plot
>factor. There would then be four treatments: 1) OP under BMP(OP), 2)
>under BMP(OP), 3) OP under BMP(hyb), and 4) Hybrid under BMP(hyb).
>What this would mean in practice, is that each location would, in a sense,
>conduct two trials, one using standard hybrid corn practices and one using
>practices optimal for the OP. We will need to work on the exact definition
>of the BMP factor and the important details of experimental design and
>> 3. Let each crop compete under a range of growing environments - not
>> "low input" per se but on healthy (disease suppressive) and unhealthy
>> soils (as per Chuck's message; there is an increasingly alarming
>> range of journal lit on this very interesting topic), in dry and wet
>> conditions, etc. etc. This will let us test the robustness of the
>> genetics of the two corns.
>Absolutely! IMO, replication across environments is much more important
>than replication within environments. The more sites we can get the
>If some cooperators can only offer one plot or strip for each of the four
>treatments, fine. We can accomodate that statistically. If some
>collaborators could only perform one kind of BMP instead of both, we can
>probably accomodate that too.
>> I can find a grower who has selected his own OP corn, here close to
>> Guelph, who might be able to contribute some seed. He came in and
>> spoke to our corn breeder recently.
>Variety selection is crucial to maximize the value of this experiment.
>Let's decide after we see where the sites are located. If we end up with a
>wide enough range of regions, we might want to use different pairs of
>varieties for the different regions.
>> I have been told by a knowledgeable and well respected plant breeder,
>> that had as much effort been expended in breeding OP corn as has gone
>> into hybrid corn, the yields would be as good.
>Three reasons why hybrids might be better in an absolute sense include:
>1. Line development efficiently unmasks deleterious genes.
>2. Heterosis may involve non-additive and non-Mendelian gene action.
>3. Open pollination precludes (because of pollen competition) selection
>against apical dominance, and resulting increased sink strength of ear
>shoots found in hybrid corn.
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