June 23, 2005 Volume 4 Number 10
1. View from the Field
2. Soybean Disease Update
3. Velvetleaf In Corn Fields
4. IPM for Stored Grain
5. Unusual Injury in Alfalfa
6. Green Lacewing in Alfalfa
7. Clipboard Checklist
8. Growing Degree Days in NYS
9. Upcoming Meetings
10. Contact Information
From the Field
problems of note arose this week, including a serious infestation of
seedcorn maggot in soybean in Genesee County, as reported by Mike
Stanyard (NWNY Team). Third and fourth instar alfalfa weevil larvae are
still easy to find, but I did not scout any fields with more than 20% of
stems showing feeding damage. While no potato leafhopper nymphs have
shown up in sweep samples yet, adults are numerous, though well below
threshold numbers. I continue to see soybean aphid in all the soybean
fields I visit. Numbers of aphids remain low, and numbers of lady
beetles seem to be increasing. Septoria brown spot has shown up in
soybean fields in Ontario County. This leaf disease is prevalent in the
areas that were very dry in early June then received several inches of
rain over the last week. See article and photograph below for more
information on Septoria. In Roundup Ready soybeans that have not been
treated yet for weeds, there continues to be plenty of new annual grass
and broadleaf weed emergence.
This week I
found glume blotch disease in the heads of triticale in Tom Kilcer’s
(Rensselaer County) research plots at the Valatie Cornel Farm. Blotch
glume disease lesions begin as either grayish or brownish spots on the
chaff, usually on the upper third of the glume. As lesions enlarge, they
become dark brown and the centers turn grayish-white in color as tiny
brown or black dots (pycnidia) develop within them.
discover ants on soybean plants at the Valatie Cornel Farm. Ants protect
soybean aphids, so with a closer look I found aphids on new emerging
SUNY Cobleskill farm I found many adult and pupating alfalfa weevils.
This means that their life cycle is almost complete for this season.
Potato leafhoppers in alfalfa were at very low numbers this week. I also
saw much velvetleaf and yellow nutsedge in the corn fields.
Stavisky, NYS IPM
Rust has still not been reported outside of Florida and southern
Georgia. Sentinel plots across the soybean growing areas of the US are
being watched vigilantly, especially following Tropical Storm Arlene a
couple of weeks ago. Regular checks to the
York soybean rust site are a must.
updates are available on the USDA soybean
potential for soybean rust in New York provides an opportunity to review
and become more familiar with common foliar fungal diseases of soybean
that are generally non-economic. Here are a few of the key diseases to
watch for with tips on how to distinguish each:
spot (Septoria leaf spot)
Symptoms appear first on lower leaves
Early signs are small irregular brown spots on upper and lower leaf
Later Symptoms are large brown-black necrotic blotches throughout
the soybean canopy
Early Symptoms: Small gray lesions on the underside of lower leaves;
lesions increase in size and become tan or reddish brown.
Later Symptoms: Leaves of the whole plant turn yellow, and small
brown or reddish raised pustules appear; the resulting necrosis
causes leaves to drop.
information on how each of these diseases differs in symptoms from
soybean rust, check out the
USDA identification guide.
Velvetleaf In Corn Fields!
monitoring corn fields this week I saw an abundance of velvetleaf.
Research from Purdue University suggests that just 1 velvetleaf plant
per row foot, if not controlled in the first 4 to 6 weeks after
planting, can reduce yields by 25 percent. Twelve plants per row foot
can reduce yields by 57 percent. This means the earlier you can control
them the better the yield. Research by our own Janice Degni (South
Central NY Dairy Team) and Russ Hahn (Cornell Crop & Soil Sciences
Department) has shown that velvetleaf yield impacts on corn were also
highly affected by soil moisture. The more droughty the soil conditions
were, the more significant the impact. Research continues to look for
better weather prediction data to help us with developing this
threshold. For management information check our on-line IPM guides:
in Corn Management Guide
Wise, NYS IPM
is the key to keeping insect pests out of your stored grains. Wheat
harvest is not as far off as you may think so knowing what you need to
do is important. The following is a step by step method for IPM in
grain handing equipment (augers, combines, wagons, scoops, and trucks).
inside the grain bin (remember to clean under the false floor). Mice,
moths, weevils and much more can survive under the false floor.
around the outside of the grain bin. Remove all weeds, spilled grain and
debris 6 to 10 feet from around the grain bin. This will remove all
habitats that can support a grain bin pest problem.
all cracks and crevices. Cracks are prime locations for insects to enter
fans when they are not being used. Insects can enter the grain bin this
6. Use a
registered sanitizing insecticide spray in and around the structure
store new grain with old grain.
the grain bin before adding new grain. Insect pests need moisture to
the surface after filling the grain bin. Moisture accumulates in a grain
peak. Microbial activity in the wet area will heat up and attract
secondary insect pests.
not fill grain bin all the way to the top. Leave a few feet for
Aerate the grain to at least the ambient temperature. The hotter the
grain gets the faster insect pests can develop. Stored grain insect
pests development slows when the temperature falls below 500
Monitor grain for insect pests every 20 days from spring till fall and
every 30 days in the winter.
you discover an infestation of insect pests you may consider an
insecticide application. Select a NYS registered product for your stored
grain. READ THE LABEL.
areas around grain bins mowed to limit rodent hiding places.
following are common insect pests of stored grains: Common Insect Pest
of Stored Grain, Granary weevil , Saw tooth grain beetle, Red flower
beetle, Larger cabinet beetle , Lesser grain borer, Rice weevil,
Indian-meal moth, Flat grain beetle, Angoumois grain moth, Confused
Injury in Alfalfa
Stavisky, NYS IPM
seen any unusual injury on alfalfa? It might be caused by the four-lined
plant bug. This week, Bruce Tillapaugh (Wyoming County) and I saw many
of these bugs and a surprising amount of the damage they cause.
adult four-lined plant bugs are 3/8” long, and are a bright lime green
color with four black stripes running down the back (see photo). Nymphs
are bright red to orange (I didn’t see any to photograph). They are
commonly found on many plants, including potatoes, alfalfa, and
Four-lined plant bug adult in alfalfa
four-lined plant bugs are a true bug and have piercing-sucking
mouthparts, we wouldn’t expect the injury to look like defoliation,
usually typical of insects with chewing mouthparts. The four-lined plant
bug causes the damage by removing the plant’s chlorophyll in small,
relatively uniform patches on the leaves (see photos below). The result
is a translucent spot, or “window” where the upper and lower epidermis
are still intact. In our observations of the feeding damage in alfalfa
this week, where severe damage had occurred on several leaves of new
growth, the top sections of plants were pale colored and wilted.
caused by the four-lined plant bug is eye-catching, especially if there
are many plants showing feeding injury within a small area. However,
feeding by this bug is not generally of economic importance in alfalfa.
Four-lined plant bug injury in alfalfa
lacewings in Alfalfa!
observed a few green lacewing adults in my sweep net this season in
alfalfa fields and by the porch light at night. Adults feed during
the evening on nectar, pollen, and aphid honeydew. Larvae are very
active predators of aphids and other small insects in many agricultural
crops. Adults are light green with long, slender antennae, golden eyes
and large lace-like wings that are 1/2 to 1/3 inches long. Larvae are
called aphid lions, and look like little green-gray or brownish
alligators. Aphid lions have sickle-shaped jaws, that penetrate the prey
s a paralyzing venom, then suck out the victim’s body
fluids. The larvae will reach about a1/2" long before they pupate.
crop production activity records by field, including harvest date,
pesticides used, nutrient inputs including manure, etc.
Established Alfalfa and Hay:
Monitor for Potato leafhopper
Monitor for anthracnose, look for shepherd’s crook symptoms
Monitor fields for weeds and diseases: record information on type and
location for future cropping decisions.
Evaluate weeds and adjust post-emergence treatments
Cultivate or treat if necessary
Monitor insects (cutworm, rootworm, wireworm, etc.), slugs, and foliar
diseases (anthracnose leaf blight, eye spot, gray leaf spot, etc.)
Pre-Nitrogen Sidedress Soil Test and apply sidedress as needed
Evaluate stand for emergence issues, plant population
to monitor for soybean aphids, soybean rust
fields for spider mites, Septoria brown spot, and downy mildew
condition of flag leaf for cereal leafbeetle and foliar (and head)
Continue watching for wheat head diseases including glume blotch, scab,
smut and take all.
grains have headed out. Continue scouting for powdery mildew and cereal
Insecticidal ear tags for heifers on pasture
management and initiate release of biological control agents (parasitic
wasps) for house fly and stable fly control in confinement facilities.
condition of pastures and animals on pastures
pasture rotation as necessary
Evaluate need for face fly and stable fly control measures
Prepare small grain combining equipment or arrange for custom combining
grain handling and storage equipment, augers, bins, fans.
Degree Days in NYS
Stavisky, NYS IPM
March 1 -
June 21, 2005
Base 48 F
Base 50 F
July 6 -
Wednesday - NY Weed Science Field Day, Valatie Research Farm. Valatie,
July 7 - Thursday - Seed Growers' Field Day, NYSIP Foundation Seed Barn,
Ithaca, NY (791 Dryden Road, Route 366)
July 13 - Wednesday - NY Weed Science Field Day, Robert B. Musgrave
Research Farm, Aurora, NY (Poplar Ridge Road, connects 90 and 34B)
July 14 - Thursday - NY Weed Science Field Day, H. C. Thompson Research
Farm, Freeville, NY (10 miles Northeast of Ithaca, Fall Creek Road, Rt.
July 15 - Friday - Aurora Field Day, Robert B. Musgrave Research Farm,
Stavisky: IPM Area Educator, Livestock and Field Crops, Western NY
Phone: (315) 331-8415
Fax: (315) 331-8411
Keith Waldron: NYS Livestock and Field Crops IPM Coordinator
Phone: (315) 787 - 2432
Fax: (315) 787-2360
Ken Wise: Eastern NYS IPM Area Educator: Field Crops and Livestock
Phone: (518) 434-1690
Fax: (518) 426-3316