Fw: Interesting ...

[Paul Cherubini]

Mark Deering wrote:

> I am certainly not arguing that the scientists in the article 
> were stating what cultural practices were spreading milkweed. 
> However, you certainly did add Roundup to their statement about 
> "herbicides are widely used".   You made it sound as if they 
> believe Roundup does no harm to milkweed,  though I do not 
> believe that this was what they were saying (point 5 on your 
> list).

Yes, Mark,  I added Roundup to their statement because it is, 
in fact,  one of the widely used herbicides which, in the authors' 
words "often do not harm common milkweed but control most 
annual weeds that would otherwise compete with it."

In other words, at application rates TYPICALLY used on cropland 
Roundup causes little or no injury to common milkweed, but does 
kill the annual grasses that would otherwise compete with it, 
hence Roundup is beneficial, OVERALL, to the growth and spread 
of common milkweed growing in cropland in eastern Nebraska 
(a prime area of summer monarch reproduction).

As the authors pointed out, there are certainly ways growers 
could use Roundup (and some of the other herbicides the authors
originally said often does not harm common milkweed) if they 
wanted too.  But in practice, growers do not normally bother with 
these other methods because they cannot justify the cost of a
milkweed specific herbicide treatment.   They are primarily 
interested in killing the annual grasses that Roundup kills at low 
application rates.

> As to your deliberately spraying Roundup on your milkweed 
> patches, good for you! I suppose that you make sure that there
> are no monarch caterpillars onmthe plants first, right? I do not 
> believe that herbicides are the answer there Paul, try pulling the 
> weeds by hand. I am sure that the destruction of all above ground 
> portions of the plant in the spring is not exactly healthy for it.

Again we have a misunderstanding.  A month ago, (March 15, 
2002) BEFORE the milkweed emerged from my milkweed garden, 
I sprayed Roundup on the carpet of annual weeds that was covering 
the ground in this garden.  A month later, (April 16) these annual 
weeds are all dead but healthy milkweed is emerging from underground 
milkweed rhizomes:
http://www.saber.net/~monarch/yard2.JPG

Thus, in this way, Roundup can be used to create a thick stand of 
milkweed. I find hand - pulling the annual weeds is impractical and rips 
up the soil causing heavy erosion when a rainstorm strikes.  

Paul Cherubini

 
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