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AgAlerts 2003 From Griggs County
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Issue # 9, August 5, 2003
The month of July came and went too fast. Between the Griggs County Fair and 4-H Achievement days, trying to sweep for leafy spurge beetles, horticulture and field calls and vacation, I failed to keep up these AgAlerts. The leafy spurge beetle collections were down this year. We could not find large collectable numbers to warrant any collection days. We are not the only county to have this problem. Barnes county had similar collection efforts. We are trying to find out why this has happened and hope collections will continue in 2004.
NDSU field scouts have been finding soybean aphids in our area but, have not found populations high enough to treat. Threshold levels for soybean aphids are 25 aphids per leaflet or a total of 200+ per plant. Greatest numbers have been found in sheltered areas near shelter belts or wooded areas. So far, a few fields have been treated in the Hillsboro area. At this time we have not seen significant numbers in Griggs county but are continuing to monitor fields for any changes. For more information and pictures of soybean aphids, consult Extension publication, E-1232, Soybean Aphid Management in North Dakota.
Several call over the last two weeks have
concerned the die back of cotoneaster shrubs. The main cause has been
fireblight. Fireblight is a destructive
disease of apples, crabapples, pears, cotoneaster and mountain ash. Infection
usually occurs in spring when the trees are flowering or during the growing
season after a hail storm. The disease causes the flowers and fruit to wilt, dry
out and turn dark colored. Branches or stems may be killed back just a few
inches or completely. Diseased leaves and fruits hang on fireblight-killed
branches throughout the summer and fall.
Control: Fireblight can be controlled by pruning or
with the use of a streptomycin treatment during blossoming. This treatment
should be reapplied every 4 to 7 days for a total of three sprays. Pruning
should be done in the early spring or late fall. Avoid pruning during the
growing season unless the disease is advancing rapidly and could possibly kill
the whole shrub. Since fireblight is caused by a bacteria, there are some
major sanitation practices that must be followed. When pruning, cut 8-12
inches below the edge of the infected area or canker. Cankers can be found by
looking closely at the bark. Infected areas, the bark will be shrunken
around the heartwood of the branch in question. Look for the area that is
a transition from the shrunken bark to normal health bark. After each cut,
sterilize the pruner by dipping it in a solution of 1 part bleach and 9 parts
water. Non sterilized pruners will spread the disease as you prune. Paint all
pruning wounds with a pruning paint or latex house paint.
Cultural practices include; avoiding heavy use of fertilizer
and water, as this promotes succulent growth which is very susceptible to
fireblight.
(Click on photo's to enlarge)
Recent rains have caused a set
back to barley harvest. Producers might want to look at natural air drying
to resume harvest earlier. The following are recommendations by Dr.
Kenneth Hellevang, PE, Ag. Engineer-Post Harvest/Structures Specialist at NDSU.
An airflow rate of 0.75 cfm/bu should dry 17% moisture barley
in about 20 days during late July and August. This airflow rate should be
considered the minimum for natural air drying barley and 17% moisture should be
considered the maximum safe moisture content to assure that the barley dries
before there is a quality loss.
Germination is critical for malting
barley. Mold will grow on the germ of the seed and affect germination before
mold is visible. The safe storage period, based on germination, for barley at
17% moisture and 68EF is about 35 days, but is only
about 19 days at 78EF. At 18% moisture, the safe
storage period is about 26 days at 68EF, but is
only about 13 days at 78EF.
Barley temperature in a drying bin will be approximately the
average of the daily maximum and minimum plus about 3 to 5 degrees for the
amount that the fan heats the air. The average temperature for July is about 72
degrees, so if the fan heats the air about 4 degrees, the air temperature
entering the bin is expected to be about 76 degrees. As moisture is evaporated
from the barley in the drying zone, the air is expected to cool about 5 to 7
degrees. Therefore, the wet barley temperature above the drying zone would be
expected to be about 70EF when the average outdoor
temperature is about 72 degree.
For more information on Natural Air Drying, consult Extension
publication, AE-701, Grain
Drying.
Spotted knapweed continues to
be a concern in the southeastern part of Griggs county and Northeastern Barnes
county on the west side of Lake Ashtabula. At this time the Barnes county
weed board has been spraying the areas in question but each year they find new
stands. The reason for concern is its capibility for rapid spread.
North Dakota is like an island. The states surrounding us all have spotted
knapweed problems. At this point, only isolated areas have problems.
Spotted knapweed is very competitive. It can out compete leafy
spurge. In states that spotted knapweed is a problem, they do not worry
about leafy spurge but all efforts are towards spotted knapweed.
The Griggs County Weed Board is asking everyone to be on the
lookout for this weed. If you find any spotted knapweeds or have a
question whether it is spotted knapweed, contact the Griggs County Extension
Office at 797-3312. Our main concern if this weed gets established in
CRP. Spotted knapweed can be confused with Canadian thistle at blossom
time due to the color of their flowers. So help us keep this weed in
check. For more information on identification, consult Extension bulletin,
W-1146,
Know Your Knapweeds.
Please Contact Our Office For Additional Information
E-mail: john.swenson@ndsu.edu
Go to the 2003 AgAlert Index Page