A2B-L«ncaster Farming, Saturday, July 9, 1994
By Using Quality Adjuvants, Herbicide Rates, Costs Can Be Reduced
ANDY ANDREWS
Lancaster Fanning Staff
HOLTWOOD (Lancaster Co.)
Pesticide applicators may be
able to save as much as $B-$9 per
acre on herbicide costs by using
quality forms of adjuvants, accord
ing to information provided during
a field day held at the Steve Groff
Farm last week.
About IS farmers and agri
industry representatives viewed
the test plots on Groffs 175-acre
vegetable and cash grain crop
farm.
Sponsored by Groff, the Pen
nsylvania Association for Sustain
able Agriculture (PASA), and
Agri-Basics Soil Service, the field
day showed how using adjuvants
can contribute to weed reduction
and improved stand on no-till com.
In a summary provided at the
field day, Groff stated, “I know
that chemical companies spend
millions of dollars to come up with
acceptable rates for their products.
I feel that with a little common
sense and a few other tools such as
adjuvants and proper timing, you
can cut herbicide rates and reduce
costs.”
Adjuvants are applied with the
herbicide at spray time to do a
number of things. They vary by
type and include:
• Compatability agents. These
adjuvants help certain herbicides
combine to promote improved
effectiveness.
• Buffering agents. These lower
or raise the pH of the water in the
spray tank to make the herbicide
more effective.
• “Applicator” or “sticker”
adjuvants. These allow the pesti
cide to adhere more precisely to
the leaf surface in post-emergent
applications.
• Surfactants. These decrease
the ‘ ‘surface tension’ ’ of the water.
This tension makes the water
* ‘bead up’ ’ on the leaf surface. The
adjuvant spreads the water out
over leaf surface and also helps
distribute the herbicide over a
wider area and with more penetra
tion in the soil.
Groff used APSA-80, an adjuv
ant available from Amway. With
no-till com, Groff indicated he had
“good success” with the early
preplant program, spraying 2-3
weeks before planting. On a fact
sheet, records indicate that he
sprayed 1.25 quarts per acre of
Bicep with the adjuvant the first
week of April, then planted the last
week in April. He then followed up
with 1 quart of Prowl as com
emerged to kill lambsquarter.
By spot-checking the fields at
the beginning of the season. Groff
said it looked like using the adjuv
ants helped.
“That was the intent of this pro
ject,” he said. “What we’re doing
is making the herbicides more
active in the soil.”
Through calculations supplied
by Groff and PASA, on plots 1-6,
rates of Bicep were cut in half,
from 2 quarts to 1 quart, reducing
costs from $14.55 to $7.25 per
acre. The rates of Prowl were cut
from a quart to a pint, from $5.96
to $2.98 per acre. The adjuvant
was supplied at a rate of 5 ounces
per acre at a cost of $ 1.15 per acre.
On plots 7-10, Bicep rate was
cut from two quarts to about 1.25
quarts per acre. Adjuvant was
applied at the same rate.
Using the dual herbicides, sav
ings came to $9.13 per acre.
Groff cautioned that there was
more to the equation than simply
the adjuvants. Another factor
included the timing of the herbi
cide (he said he applies the chemi-
cals right before a rain). “It has a
lot to do with management,” he
said.
Also, choosing a quality adjuv
ant is essential. Some adjuvants
include alcohol as a stablizer. But a
quality adjuvant will have the
adjuvant material at about 80 per
cent or more of the active
ingredient.
Farmers can profit from trials
such as these. Savings can be
substantial.
“An $8 savings per acre, I think,
is worthwhile talking about,” said
Edgar Rits, a consultant from Hon
ey Grove at the field day. ‘ ‘That’s
less herbicide you need to put
down. That’s the big issue.”
Harvest data on the com yields
as a result of using the adjuvants
will be provided in the fall.
Groff said that about 75 percent
of his com is in no-till and the rest
in slit till. A rotation of his com
every two years at maximum also
helps to cut down the incidence of
weeds and insects.
“I generally don’t have a prob
lem with insects in com because of
rotation,” he said.
Other studies included the use of
calcium with the spray, which had
little effect on weeds and showed a
ANDY ANDREWS
Lancaster Fanning Staff
LANDISVILLE (Lancaster
Co.) There may be no “magic
bullet” to take care of all a far
mer’s long-term weed problems in
soybeans, especially in reduced til
lage situations.
But that doesn’t stop many man
ufacturers of herbicides and seed
varieties from at least trying.
One attempt is being made by a
manufacturer, Monsanto, to deve
lop a variety of soybean that is
resistant to its own herbicide.
Roundup. Research is under way
at Penn State to study how effec
tive the new biogenetic gene is to
not only the Monsanto herbicide,
but to a variety of other herbicides
from other manufacturers.
More than 100 agri-industry
representatives were on hand to
see some results of this and other
soybean and com herbicide trials
conducted at the Penn State Land
isville Research Center during the
annual Weed Tour on Thursday
morning.
Dwight Lingenfelter, Penn State
graduate student and extension
assistant, spoke about the effec
tiveness of Roundup for perennial
weed control in transgenic soy
beans. He said the trials are look
ing at long-term control of the
warm season perennial weeds,
such as hemp dogbane. Johnson
grass, bindweed, and others.
Conventional tillage has helped
control weeds. But with conserva
tion compliance, reduced tillage is
necessary, which has presented
unique problems for growers in
controlling weeds.
For reduced tillage, postemer
gent herbicide treatments are
necessary, especially the grasses.
But for most applications, the solu
tion only lasts one season, not
long-term.
'‘Effective control programs do
not exist,” saidLingenfelter. “We
need long-term management for
rotational crops.”
While there is no magic bullet to
solve long-term weed problems, a
concerted effort involving the right
slight adjustment of the pH. What
Groff found is that water pH will
directly affect the performance of
the herbicides.
‘ ‘lt would be good if you would
check the pH of your water,” he
said. He spoke about a chart that
lists the most effective pHs for sev
eral different types of herbicides.
“There is a difference,” said
Groff, indicating that some require
a neutral pH and others require
more acidic levels.
For atrazine-based herbicides,
the half-life at a water pH of 8 is
only a half hour. But a a pH of 5 or
6, die half-life extends to 8 or 9
hours. It’s not uncommon to get a 7
or 8 pH in water supplies.
Other fields include com incor
porated into oat stubble in reduc
ing herbicide use. The oat material
stopped the weeds, according to
Groff.
Dramatic results were achieved
after a hay field was plowed in the
fall and only harrowed to two
inches deep in the spring. The fall
plowing got rid of die weeds that
germinated, cutting off seed pro
duction. A light disc harrowing in
the spring only removed the seeds
that sprouted on the top.
No ‘Magic Bullet’ In Controlling
Weeds In Herbicides
soybean variety, good herbicide
treatment, timing, and rotation can
go a long way, according to the
graduate student.
Other herbicides compared in
the long-term Penn State study, at
Landsville and at Rockspring, will
look at a variety of other herbicides
with the new variety. According to
Bill Curran, assistant professor,
weed science, the new Monsanto
variety won’t be available for com
mercial use until at least 1996.
“We need this research in order
to better utilize effective control
measures and, for the importance
of conservation compliance, it’s
necessary to integrate weed con
trol approaches in order to manage
these problem weeds we have,”
said Lingenfelter. These methods
include “biological, chemical,
mechanical,” and other means.
Canada thistle is a predominant
weed in soybeans, according to
Curran. Curran provided detail
about reduced herbicide treat
ments at various timing and incor
poration rates, including using
diphenyl ethers for broadleaf weed
control, for treating thistle and
other broadleaves.
Com herbicide treatment infor
mation was not observable at the
field day because of severe weath
er the night before. Wind damage
cut com standability by up to 10
percent in one field at the research
center, sheering off stalks. In one
plot, a power line went down.
John Yocum, manager of the
research farm, spoke about studies
that proved that weed germination
in full-season beans peaks about
the first week of June. But one
rinding was that there was con
siderably less weeds in no-till
ground than in conventionally
tilled soil. But stands depend on a
lot of factors, including the weath
er and other conditions.
Also, research continues to indi
cate that without a canopy, and
with sunlight hitting the soil sur
face, according to Yocum, produc
ers are losing yield on soybeans.
Also at the field day, Ed Werner,
Penn State research technician and
“An $8 savings per acre, I think, is worthwhile talking
about,” said Edgar Rlts, a consultant from Honey Grove,
left. He reviews application Information with Steve Groff.
There are no weeds where the
tomatoes are growing.
‘ T credit it to the fact that it was
plowed in the fall,” he said. “We
took care of it by harrowing
twice.”
Groff said that it ‘ ‘really pays to
plow in the fall for late-planted
Dwight Lingenfelter, Penn State graduate student and
extension assistant, spoke about the effectiveness of
Roundup for perennial weed control in transgenic soy
beans. He said the trials are looking at long-term control of
the warm season perennial weeds, such as hemp dogbane,
Johnsongrass, bindweed, and others.
graduate student, spoke about his
work with a weed economic
threshold study in com. Rob Paiks,
graduate research assistant, agro
AOSI
i. PAY OFF! k
tomatoes. We’ve just had no weed
problems.
“You have to try this yourself
on your own farm," said Groff. “I
think that’s what this demonstra
tion shows there are some
things you can try on your own
farm and tell people about’’
nomy, spoke about his work on
(rials involving triazine-resistant
lambsquarters, the most common
annual broadleaf in the state.