A2B-lancaster Farming, Saturday, February 19, 1994
VERNON ACHENBACH JR.
Lancaster Fanning Staff
LANCASTER (Lancaster
Co.) The common element in
talks given by crop experts Tues
day during the 33rd Lancaster
County Crops and Soils Day was
“management.”
Sponsored by the Lancaster
County Extension Service and
supported by Lancaster Farm Cre
dit Association, Hamilton Bank,
and other agribusinesses, about
200 people attended the event held
at die Lancaster Farm and Home
Center, despite snowfall predic
tions of up to several inches.
Speakers 'included Penn State
University crop experts Dr. Dennis
Calvin, Dr. Greg Roth, and Dr.
Douglas Beegie, and Lancaster
County Extension Agent Robert
Anderson.
Calvin discussed management
for com rootworms and considera
tions for early season pest manage
ment, focussing on the stage of
development from seed through
sprouting, to the fourth-leave stage
of development.
According to Calvin, com root
worms can be managed using test
ing and a system of checking for
levels of the pest before applying a
pesticide. Rotational strategies can
also keep pest population levels
below that which would impact
financial returns.
In addition to rootworm, Calvin
also talked about spring pests and
said that it needs to be understood
that insect pests are not present in a
field without reason; that there arc
characteristics about fields which
serve to attract pests.
He said that in order to under
stand management for pests, an
understanding of the pest and its
behavior and nature is essential.
With knowing what attracts
pests, what they prefer to feed on,
and the basics of the life cycles, a
cropman can better “read” his
fields for potential problems and
better be aware of when he has a
problem.
And, it should be understood
that during the early phase in
development emergence to 4th
leave stage the plant is primari
ly depending on energy stored
within the seed. Any damage to
emerging roots or stalk can be fatal
to the plant, because it can’t make
up the difference in energy.
Damage in the pre-4th leave
stage can also show up in reduced
yields, in the long run.
When seeds are planted they
absorb water and begin respira
tion, producing carbon dioxide.
The carbon dioxide is also an
attractant to insects such as wirew
orms, white grubs and seedcom
maggots, he said.
This is important to understand
because a decision can be made
with respect to pests and whether
to use a soil insecticide, or a seed
treatment, depending on which
pest is in a field, and whether it
may be there in a level high enough
to damage yields.
Calvin presented several scenar
ios in which a producer could take
justifiable preventative action.
For example, in the case of the
seedcom maggot, Calvin said the
adults ate first drawn to a field
because of decomposing vegeta
tive matter, which produces vola
tile organic chemicals that attract
them.
Such obvious fields are those in
which no-till planting and surface
residue is significant, or in which a
lot of manure has been applied.
The eggs are hatched and the
larvae then migrate toward the car
bon dioxide in the seedling.
Crops Experts
The cure would be to use treated
seed, Calvin said.
Another example of the benefit
of knowing about insects pest
behavior involves wireworm,
which can decimate com.
Calvin said that wireworm is
more of a feeder of grass roots, par
ticularly blue grass. In a field that
has been converted from grass
within the past five years, wirew
orms can be a problem, because
unlike most of the com crop pests,
wireworms have a 2- to 3-year life
cycle.
Thus they can remain a pest to
crops planted in the soil for years
after conversion from grass.
Calvin said that a seed treatment
can helps, as well as can a soil
treatment, but that they can be dif
ficult to control because they will
move through the substrate with
the varying levels of moisture and
can actually escape coming into
contact with a pesticide until after
the chemical breaks down and is
no longer effective.
The black cutworm is probably
the second most common problem
in Pennsylvania, according to Cal
vin. He said normally by the time
that a problem is visually noticed,
it is too late to prevent serious
damage.
However, control of the black
cutworm can be done through
management of winter annual
weeds, such as common
chickweed.
What frequently happens is that
the migratory moth of the black
cutworm flies north and lays eggs
on weeds such as common chick
weed. he said.
In the spring, a chemical bum
down removes the cutworm
infested chickweed, but doesn’t
injur the cutworm larvae. They
migrate to the com plant.
Other weeds which attract cut
worm are Shepherd’s Purse and
varieties of the wild mustard.
A stand of alfalfa can host them
also and damage can occur to com
planted against alfalfa, he said.
According to Calvin, if the far
mer can get into the field to bum
down the chickweed from 10 to 14
days ahead of planting, then the
cutworm larvae die from lack of
nurishment, before they can
opportunize the com.
Calvin also reviewed the sod
webworm, slug, common stalk
borer, billbug (Which depends on
yellow nutsedge, a plant asso
ciated more with wetlands, for its
lifecycle.), and the army worm,
even though it is usually associated
with crop damage during a later
stage in development, such as mid
to late-June.
The army worm, for example,
lays its eggs in rye, and then when
the rye is removed, the larvae
migrate to the com.
In other business. Dr. Greg Roth
discussed producing quality silage
and managing com for profit
Roth said that 70 to 75 percent
of the dairymen surveyed were
found to be growing com silage
because of its consistency as a for
age, the mechanical aspects of it,
reduced labor, and its volume of
harvest, which is important espe
cially in areas where season length
limits haymaking.
In attempting to produce quality
com silage, he said most producers
take either a defensive or an offen
sive approach.
A defensive approach to making
silage is to select a limited amount
of acreage for com, and depending
on the result of the season, decide
at harvest time how much is going
to go toward silage.
Roth said that for some areas of
Advise On Plant Planning
Pennsylvania, especially those in
which soil and weather conditions
present a more upiedictable crop,
such a strategy is good, because of
its flexibility.
A defensive strategy to silage
production would incorporate a
similar management as for grain,
modest plant population levels,
medium length maturity, soil fer
tility based on grains, in addition to
silage fields being selected at
harvest
However, in other areas of the
state, especially for large dairy
operations, an offensive approach
is preferable because it can reduce
risk of coming up short with
forage.
An offensive strategy would be
characterized as management
being based on the crop’s end use,
higher plant populations, a longer
maturity, fertility based on the
crop’s use as silage (Potash is lost
from soil more rapidly with silage
than with grain com because of the
removal of the whole plant, rather
than a portion of it.), and with sil
age fields being selected before
planting.
The first step in planning the
crop is to determine how much is
needed. Roth said that for every
pound of silage fed, an additional
18 percent is needed because of
expected losses. Other crops can
require planting as much as 30 per
cent more than anticipated need,
he said.
The expectation is that a quality
silage should result more frequent
ly from a program directed at pro
ducing silage, than in a program
that treats silage as an option.
According to Roth, offensive
style planting rates would be from
23,000 to 30,000 plants per acre
(ppa}, at least 2,000 to 4,000 more
ppa than with grain plantings.
He said some people are now
looking at planting even higher
rates with 13-inch rows and
harvesting it with modified equip
ment so that row direction in
harvest is not a strong factor
the harvester can operate equally
well in any direction.
And while he said research into
that technique looks promising,
substantiating research is still
being performed and a lot of ques-
tions still need to be answered.
Soil tests on silage ground are
Students Pr
;Ocatk>m _ jhool demonstrations will be part of the 1994 Builders Show
February 26 to March 6 at the Farm Show Complex. FFA Chapters and 4-H Clubs will
be participating, along with other vocational organizations. Two-hundred students
will be helping with displays and demonstrations. The “Wonderful Wetlands" display
shown above has been prepared for the show by the FFA Chapter at Dover High
School. Presenting the display are from left, Brian Smyser, a senior, and Mike Boyer,
Jon Bish, and Harry Border, all Juniors.
recommended, because of the use
of potash, and also to ensure that
the resulting crop has enough pro
tein content from adequate nitro
gen levels.
Hybrid selection is also a factor
in managing for quality silage.
Roth said that selecting for
maturity is very important, and
that longer maturities help
there is a correlation between
length of maturity and yield.
However, he said that potential
harvesting' problems (such as
whether a producer can normally
get into a field at certain time of the
year), livestock feeding require
ments, silo filling time, and the
adaptability of the hybrid should
all be considered.
He talked about his work grow
ing tropical varities of com in Pen
nsylvania, as an example of adap
tation. He said while the 12- to
13-foot high stalks initially appear
as though they should produce
mote silage, the quality isn’t as
high because it doesn’t resist pests
as well and he wasn't able to get
grain development to levels that
justified using the plant.
He said he also did work with
“open pollinated” seed and his
results showed that this resulted in
even poorer silage, because of var
iation within the field and in
plants.
He said that yield data should be
used whenever possible in select
ing a hybrid. The differences in
yield can be great, he said, and
while other considerations are
important, yield data is the best
information.
Stress tolerance should be con
sidered as well as the particular
nature of the field and local envi
ronment in which a hybrid is being
considered for planting.
He said yield is probably the
most important factor, while stress
tolerance is probably the second
most important.
Energy content in silage has
caused a lot of confusion in the
past couple of years, according to
Roth.
He said that Held reports are
showing some range in apparent
effectiveness, though laboratory
tests indicate nutrient values about
equal.
Differences in lignin content,
which is a nondigestable fiber in
re Display For Builder’s Show
the plant, is higher in some variet
ies and it also increases with age of
plant The lignin is used by the
plant as a structural component
and apparently is protecting some
nutrients and energy in silage from
the digestive action in the cow.
So while silage tests may be
equal, the feed value may well be
significantly different because of
dip lignin component
Crimping is being tried, but no
studies yet support the theory that
crimping com fodder before ensil
ing allows better digestabilily of
the end product
Rolling silage prior to mixing in
a totally mixed ration (TMR), in
order to crack open reserves of
nutrients is also apparently largely
untried.
The differences in lignin content
are considered to be significant
enough that research is being
directed at it he said.
The most digestible com silage
comes from plants harvested early,
while the milk line is still high in
the seed. Roth said that though
some people may have had trouble
with seeping from too young sil
age, he said that a larger, courser
cut should prevent some of that
He said that seed companies are
starting to do more work with
hybrids selected for ensiling, but in
the meantime, he said to select a
hybrid for maturity, high yield,
quality, digestibility and protein
content.
Anti-quality factors include
weed growth, late harvest and
cloudy weather. Weed growth and
late harvest are management
issues.
Roth also talked briefly about
“stay-green” com varieties, but
said that his research has shown
negligable differences in moisture
content at harvest between plants
retaining its green and those show
ing the normal brown.
“But I still think something is
there, from talking to farmers,” he
said.
Also important in making qual
ity silage is to make sure to get a
good pack and a good seal. He said
to try to eliminate air. delays in fill
ing and variability in the silo.
He said that after harvest, pro
ducers should be thinking about
soil conditions and using cover
crops.
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Wetlands