We discuss and comment on the role agriculture will play in the containment of the CO2 problem and address protocols for terraforming the planet Earth.
A model farm template is imagined as the central methodology. A broad range of timely science news and other topics of interest are commented on.
Tuesday, July 24, 2012
Roundup Resistance May Select Supercrops
What gets me is that the science is still shallowly understood for a
product applied universally worldwide for fifty years. Here we get an indication
that the bacteria mix in the soil supports the effect of the
Beyond that we also learn that herbicide resistance may naturally
select plants that are more advantageously robust. For once we have
a good unexpected consequence. There is clear merit to simply
selecting superior plant strains that can handle the biological
background. This has always been the intent anyway, but deliberately
forcing it with herbicides is not obvious.
So perhaps we can develop some super crops and save ourselves a lot
'superweeds' may be less susceptible to diseases
Wallheimer for Purdue News
West Lafayette IN
(SPX) Jul 18, 2012
found that soil microbes may play a role in how those weeds react to
the popular herbicide glyphosate. Here, glyphosate-susceptible
biotypes of giant ragweed react differently to the herbicide. The
plant on the left is in sterilized field soil void of microbes, while
the plant on the right is in unsterilized soil. (Photo provided by
searching for clues to understand how superweeds obtain resistance to
the popular herbicide glyphosate may have been missing a
critical piece of information, a Purdue University study shows.
Glyphosate, the active ingredient in the weed killer sold under the
name RoundUp, is the most widely used herbicide in the United States,
but some plants have grown resistant to it.
has caused farmers to turn to additional herbicides. While the
mechanisms that have led to resistance are not fully known, Bill
Johnson, a professor of weed science; Steve Hallett, an associate
professor of weed science; and Jessica Schafer, a graduate student in
botany and plant pathology, believe that soil microbes may play
Most laboratory tests
done to understand glyphosate resistance are done in sterile soil,
void of those microbes. Schafer said Purdue's findings, published
online early in the journal Weed Science, show that those microbes
may play a significant role in how glyphosate affects plants.
"The soil you're
growing the plants in is important to the results," Schafer
said. "If we're growing in a sterile media, we could get some
false positive results because the plants are more tolerant to
glyphosate in those conditions."
Hallett and Schafer
grew giant ragweed, horseweed and common lambsquarter in both sterile
soil and field soil and subjected them to glyphosate. In each soil,
strains of weeds both susceptible and resistant to glyphosate were
Both versions of giant
ragweed were damaged more from the glyphosate in field soil. The
susceptible version of common lambsquarter was also more heavily
damaged in field soil. Horseweed fared the same no matter which soil
or strain - susceptible or resistant.
The results show that
microbes can play an important role in the activity of glyphosate,
presumably by invading the glyphosate-weakened plants. The results
also suggest that glyphosate-resistant weeds may be more resistant to
disease pressure as well.
microbes can be minor to major contributors to how glyphosate is able
to affect plants," Hallett said. "We may be selecting not
only for glyphosate resistance, but inadvertently selecting for weeds
that have disease resistance as well."
A weed's ability to
withstand glyphosate was based on dry shoot and root weight after
testing. The sterile soil used in the study came from field soil
exposed to gamma radiation to kill microbes and bacteria. The
irradiated soil was tested to ensure that its nutrients were not
Hallett, Johnson and
Schafer said further studies would look at how fungi in the soil
affect root development, both with and without glyphosate.
"Dirt is a living
organism," Johnson said. "It's important to know how all
the pieces interact."