market-farming AT lists.ibiblio.org
Subject: Market Farming
List archive
- From: "Wiediger, Alison" <alison.wiediger AT hart.kyschools.us>
- To: "Market Farming" <market-farming AT lists.ibiblio.org>
- Subject: Re: [Market-farming] Bt Sweet Corn
- Date: Mon, 25 Jan 2010 14:27:10 -0600
Lots of good information here to help with decision
making. By the way, Josh, if you decide to use something like the
Zea-Later, here is a link for earworm lures:
Combined with a sticky trap, it will help you monitor adults
for deciding when to spray, use the Zea-Later, etc. The trap also works
very well trapping cucumber beetles (use the cucumber beetle lure), a pest
difficult to control organically. It gave us beautiful cucumbers last
season.
Alison
Wiediger, Au Naturel Farm
From: market-farming-bounces AT lists.ibiblio.org [mailto:market-farming-bounces AT lists.ibiblio.org] On Behalf Of Chris Reid
Sent: Monday, January 25, 2010 2:06 PM
To: market-farming AT lists.ibiblio.org
Subject: Re: [Market-farming] Bt Sweet Corn
Josh,
You were wondering about growing Bt corn. Especially since you
are in the Corn Belt, local experience may be really relevant. Have
you talked to Purdue or a county extension agent about what they are
seeing and hearing?
From afar I took a look to see what Purdue is saying in its
publications about ear worm and Bt corn. Other sources have said that the
primary target pest of Bt corn is the borer, and ear worm control is more
variable. Carla in OK is having what sounds like pretty good
success. It may be slightly different in Indiana - see below.
You didn't say what part of Indiana you are in.
Purdue extension talks about carefully selecting planting time as a
strategy to avoid corn ear worm damage:
"CEW (corn ear worm) usually will not survive
winters north of about Bloomington, Indiana. In southern Indiana, this
insect may attack both early and late planted corn. In central and
northern Indiana, CEW generally affects only the late-maturing crop.
Following mild winters, CEW may survive further north, and early-planted
sweet corn may be attacked. Throughout the state, corn maturing in
mid-season is less likely to be injured, because CEW are between
generations at that time, however monitoring populations is important."
They also make it clear that in their experience, Bt corn is still
not a substitute for at least some spraying. Here is a quote:
"Bt SWEET CORN There are varieties of sweet corn available that have had a gene
inserted in them that causes the plant to produce the same toxin as the
bacterium, Bacillus thuringiensis, or Bt. This toxin will
provide considerable control of corn earworm.
However,
planting Bt sweet corn will NOT eliminate the need to spray insecticides.
Bt sweet corn will often have large numbers of small earworms in the tip
of the ears, making those ears unacceptable in most markets. Particularly
in late season sweet corn, it is advisable to plant Bt sweet corn if your
market will accept it. Used in combination with insecticides, Bt sweet
corn will allow production of high quality sweet corn, even when corn
earworm populations are extremely high."
One thing they don't say but I do wonder is whether Indiana is
experiencing increases in populations of Bt resistant ear worms. The
pest pressure Purdue describes sounds higher than what Carla in OK was
reporting.
Here is the Purdue piece: http://extension.entm.purdue.edu/publications/E-31.pdf
I read a piece from the mid-80's that suggested the length of the
corn wrappers can affect the ability of the ear worms to infest the top of
the corn. I don't know if anyone regards using corn with longer
wrappers as useful to do now or not. At the time, some seed
companies were trying to find varieties of corn that had physical
characteristics making them less susceptible.
Widespread use of the same pesticide pretty inevitably leads to
pesticide resistance. Some IPM fact sheets I looked at recommended
specific planting patterns of Bt and non Bt corn and used e.g. 30-40%
NON-Bt corn for the purpose of making sure there was a group of non-BT
resistant ear worms to mate with any survivors in the Bt corn.
They are called refuges.
Here is an example of that approach to avoiding developing resistant
insects:
You asked about organic methods. Johnny's sells a corn silk
applicator that uses vegetable oil plus Bt. This may or may not be a
viable alternative time-wise, depending on how much you are growing.
Is there any price/competitive advantage of diversifying out of corn
into a less common crop that also can be timed to get the max out of
your market price? With so many corn pests around that make corn
a challenge to grow, a series of vegetable crops that corn
pests do not also attack might have pretty low pest pressure.
Chris Reid
Stamford, CT
|
-
Re: [Market-farming] Bt sweet corn
, (continued)
-
Re: [Market-farming] Bt sweet corn,
cjmaness AT juno.com, 01/25/2010
- Re: [Market-farming] Bt sweet corn, prmsdlndfrm, 01/25/2010
-
Re: [Market-farming] Bt sweet corn,
Marie Kamphefner, 01/25/2010
-
Re: [Market-farming] Bt sweet corn,
prmsdlndfrm, 01/25/2010
-
Re: [Market-farming] Bt sweet corn,
Marie Kamphefner, 01/25/2010
-
Re: [Market-farming] Bt sweet corn,
Wiediger, Alison, 01/25/2010
- Re: [Market-farming] Bt sweet corn, Bill Bradshaw, 01/25/2010
-
Re: [Market-farming] Bt sweet corn,
Wiediger, Alison, 01/25/2010
-
Re: [Market-farming] Bt sweet corn,
Marie Kamphefner, 01/25/2010
-
Re: [Market-farming] Bt sweet corn,
prmsdlndfrm, 01/25/2010
- Re: [Market-farming] Bt sweet corn, clearviewfarm, 01/25/2010
- Re: [Market-farming] Bt sweet corn, clearviewfarm, 01/25/2010
-
Re: [Market-farming] Bt Sweet Corn,
Chris Reid, 01/25/2010
- Re: [Market-farming] Bt Sweet Corn, Wiediger, Alison, 01/25/2010
-
Re: [Market-farming] Bt Sweet Corn,
Bill Shoemaker, 01/25/2010
- Re: [Market-farming] Bt Sweet Corn, Etienne Goyer, 01/26/2010
- [Market-farming] bt sweet corn, prmsdlndfrm, 01/25/2010
-
Re: [Market-farming] bt sweet corn,
sunnfarm, 01/25/2010
- Re: [Market-farming] bt sweet corn, Andrew Black, 01/25/2010
- Re: [Market-farming] bt sweet corn, John Cowan, 01/26/2010
-
Re: [Market-farming] Bt sweet corn,
SaladG, 01/25/2010
- Re: [Market-farming] Bt sweet corn, Todd Lister, 01/25/2010
-
Re: [Market-farming] BT sweet corn,
Chris Reid, 01/25/2010
- Re: [Market-farming] BT sweet corn, Bill Shoemaker, 01/26/2010
-
Re: [Market-farming] Bt sweet corn,
cjmaness AT juno.com, 01/25/2010
Archive powered by MHonArc 2.6.24.