conventional corn typically contains 3.5 to 5,5 % oil, whereas
high oil corn (HOC) can contain 7 percent or even more. i've seen
studies from the univ. of illinois showing, that corn can have
oil contents between 1.2 and 22%!! (dudley et al.; seventy
generations of selection for oil and and protein in maize, pp.
181-211, madison, wisconsin, cssa
in the top cross system, a portion of the field (about 10 percent
?) is planted with very high oil pollinators, while the rest is
planted with male sterile hybrids.
advantage: maize can be bred in a wide range of fao-numbers and
the hybrids are tested in their fertile form for environmental
influences.
problem: the pollinators are low yielding, but offer a longer
pollen shed than traditional hybrids, and they boost the oil in
the rest of the plants. nevertheless i heard that a higher plant
population than for normal corn is recommended to offset yield
loss from the pollinators (let's assume 20% lower yields for the
pollinators and 10% pollinator seeds in the seed bag : makes 2% =
20% of 10% total loss. every percent recommandation to seed more
than usual minus this 1% must be considered a relative yield loss
per plant. so: what is the recommendation?). that's why i
think, they can at best be considered yield neutral (ignoring the
price premium (dupont optimum grain wants its money ;-)).
as far as i'm informed (information on HOC is bad in europe,
because HOC's are not yet registered in whole europe), single
crosses as pollinators will be an future option. While many test
results show comparable HOC yields to regular corn, there are
even industry officials, who say that the risk of slightly lower
yields than normal corn, mainly the reflection of more risk at
the pollination stage (dry weather conditions or rain). surely
the oil content is variable, depending on growing conditions,
soil types, and several other factors. are there any data
available for this, which are not company secrets (i don't expect
you to violate corporate identity, let's say something like a
yield loss every 4th or 5th year) ? and when is the oil developed
in the seed ? farmers here are often forced to harvest earlier
than planned. how much loss of oil do the they have to expect per
week?
but that's not the problem i see. in the contrary there should be
big advantages as a potential energy plant for industrial oil and
in the far future as a gasoline substitute. HOC today it is
mainly attractive because of its good feeding characteristics,
rather than for it's oil, per se. that might change, the sum of
oleic acids don't differ much in any case. you might be
interested in the following homepage:
- information on project "chemical-technical utilization of
vegetable oils (CTVO-net)" of the FAIR-programm (fisheries,
agriculture and agro-industrial research) from the european
commission
http://www.dainet.de/fnr/ctvo/index.htm
(in english)
what makes me sceptic, is the feeding value of the HOC. up to now
it's mainly fed to chickens, pork and turkey. and all of these
animals react with minor (meaning undesirable) meat, when fed
with feed of high oil contents. ever seen chicken or pork meat
when fed with high concentrations of fat or oil ? the meat
becomes "oily" (you are what you eat ;-))).
some weeks ago i talked to 2 farmers, who produce bacon slices
and they told me, they could not sell their bacon, if fed with
the usual amount of corn. instead they need to supplement with rye
(which gives a very dense and tasty meat/bacon, better than
wheat). the test is simple: take a blunt knife and try to cut the
bacon. a good bacon can be cut with it, a fat and "oily" one will
follow the knife, but you cannot cut it. the same with chicken
meat. maybe mr. gunthrup, the feeding expert can give his view to
that problem for porc.
but evidently the american consumer accepts that meat, because
in 1997 you grew more than 400.000 ha of HOC (no newer data
available).
here in europe we have a slowly growing trend away from meat
without ANY fat to the more "marbled" meat, which is much tastier
than the "dry" meat, but TOO MUCH of "marbling" is not accepted.
and that "marble" meat can very well be produced with
conventional corn. so although there is a profit in weight gain,
this might be neutralized by consumer demands. with fat cows you
are forced to sell to manufacturers (here HOC should be a BIG
advantage) but you will have problems in the fresh meat market
(where you will be priced down).
and a last problem: higher oil content always means a larger
embryo in the seed, and that leads to more problems for seed
multiplication and esp. grading and cleaning. do i have to be
more careful when multiplying HOC ?
do you see any of these problems or are they (at least the first
one) foreign problems your european department will have to deal
with alone ?) i'm aware, that a farmer - depending on his aims -
can very welll decide himself, which corn to grow. and i'm aware,
that it might be difficult for an american breeder to write about
european conditions.
what i want to say is, that the decision for growing
HOC or conventional corn might more be influenced by consumers'
demand than from agronomic decisions or yields. your opinion (and
maybe research results) highly appreciated....
klaus
To Unsubscribe: Email majordomo@ces.ncsu.edu with the command
"unsubscribe sanet-mg". If you receive the digest format, use the command
"unsubscribe sanet-mg-digest".
To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command
"subscribe sanet-mg-digest".
All messages to sanet-mg are archived at:
http://www.sare.org/htdocs/hypermail