The Rural Voice, 2000-06, Page 49Now's the time to
walk your fields
By Tim Welbanks
Technical Information Manager
Walking your fields can keep you
on top of pests that may be causing
problems such as:
CORN:
SEED -ATTACKING INSECTS —
Wireworms, grubs, maggots and
seed corn beetles occasionally
damage seed and seedlings. The
longer germination is delayed, the
greater the chance for insect damage
to occur. Fields with less than
adequate drainage, high crop residue
and high rates of applied manure are
most susceptible to the above insects.
Planter box seed treatments with an
insecticide are a low-cost alternative
to the application of soil insecticides
(primarily rootworm control) for the
control of seed corn maggot, seed
corn beetles and low levels of
wireworm. Because these treatments
do not protect the plant once it
sprouts, there is no control of white
grubs, cutworms, rootworms or
higher populations of wireworms.
Where rootworm soil insecticides are
applied at planting, the use of a seed
treatment is not necessary.
Be prepared to walk early -planted
corn fields to monitor the progress of
germination and emergence. It is not
uncommon for April -planted corn to
take two to four weeks to emerge.
Once emerged, another week or so
passes before significant nodal root
(permanent root system)
development occurs at the crown of
the seedling. Until these roots
develop, corn seedlings are extremely
vulnerable to seed or mescotyl
damage from insects or diseases.
Additionally, slow germination or
emergence increases the risk of
underground leafing -out due to soil
crusting. Make sure your rotary hoe
or light harrows are accessible and in
working order. Be prepared to
replant if significant stand loss
appears imminent.
SOYBEANS —
When can I start to plant
soybeans? The simple answer is
Advice
right after your corn planting is done.
If soil conditions are fit, start
planting. Early planting allows the
soybean plant to get larger by the
time it starts to flower. This enables
the plant to produce more branches,
which may allow for increased pod
set.
ALFALFA—
When looking at your alfalfa
stand, it is amazing how good
survival is. To further assess survival,
you can:
• Count the crowns that survived and
are growing new shoots. Many
plants had leaflets frosted off in
February, but these plants are
regrowing well now.
• Dig some of the crowns and roots,
slice them open lengthwise and
review the health of the interior of
the plant. Brown discolouration or a
soft mush stage indicates damage.
• If one-half of the diameter of the
plant is firm and white, the plant can
recover. If more than half is
damaged, the plant does not have
enough root area to be productive.
What's a profitable stand density?
After the plants have at least six
inches of stem growth, count the
number of stems per square foot. At
that time 40 to 55 stems per square
foot will give acceptable yield while
stands with more than 55 stems per
square foot will produce optimal •
yields.0
Spring management
first step toward
productive pasture
By Jack Kyle, OMAFRA
Getting pastures started properly
in the spring is the first big step
towards a productive pasture season.
The first step is to assess the percent
legume and grass in the pasture
sward.
If legumes make up 50 per cent or
more of the stand, they will provide
sufficient nitrogen for the grasses to
be productive and applying nitrogen
to this type of pasture will only cause
the grasses to compete against the
legumes. If the pasture is less than
one-third legume than additional
nitrogen in the spring will get the
stand off to a good start and increase
the total forage yield over the season.
In Publication 296, Field Crop
Recommendations, there are a couple
of tables on page 84 that will aid in
determining the amount of nitrogen
to apply to your pasture fields.
Consider the value of the forage
on a per tonne basis and match this
value with the cost of nitrogen to
give an optimum nitrogen application
rate.
The first application of nitrogen
should be applied by early May and
subsequent applications after first
and second grazing. Pasturing is in
effect harvesting and the nitrogen
should follow the pasture rotation.
Using an example of $50 tonne hay
and $0.70 kg nitrogen cost the first
application would be 125kgN/ha or
112 lbs/ac. The second application
of 100 kgN/ha or 90 lbs/ac would be
applied after the first grazing. If
there is sufficient moisture and
growth a third application of
80kgN/ha or 70 lbsN/ac could be
made after the third grazing.
On pastured fields you can reduce
the nitrogen application rates from
the table by 1/3 as the grazing
livestock will return nitrogen to the
soil through the manure and urine.
Getting optimum production from
pastures will occur when the grass is
given sufficient time to grow and is
provided with adequate plant food to
produce optimum growth. Pasturing
too soon or too short is going to
reduce the production of the forage
grasses and will leave you short of
forage later in the season.0
All about corn seed
populations
By Greg Stewart, OMAFRA
When planting or walking your
corn fields this spring, pay attention
to whether you actually have the
desired final plant stand. So measure
off 17.5 feet of row (30 inch rows)
and count all the corn plants,
multiply by 1,000 and you have
plants per acre. In Ontario, final
plant populations should probably
range from 26,000 to 32,000 plants
per acre. If your planter is not falling
JUNE 2000 45