Website Address: http://fcn.agronomy.psu.edu/
Vol. 96:7
June 14, 1996
IN THIS ISSUE:
Correction to Field Crop News Vol. 96:6 (May 31)
Weed Tours quickly approaching
Certified Crop Advisor Corner
Production
- Slow Forage Growth and Development
- Harvesting Winter Wheat
Pest Management
- Aphid "Hot-Spots" in Winter Wheat
- Herbicide Preharvest Aids for Small Grains
- Waterhemp: Watch Out! - Another Pigweed Species
- Leafhopper Season
- Bird Control in Corn
- Corn Insects
Agent Observations
- Lebanon
- Dauphin
- Fayette
- Columbia, Montour, Upper Northumberland
CORRECTION TO FIELD CROP NEWS VOL. 96:6 (MAY 31)
The article entitled "Postemergence Herbicide Use in Soybeans" contained an incorrect
footnote reference about Poast Plus in Table 2. The footnote stated that Poast Plus
can only be used on Roundup Ready soybean varieties. This is not correct. The footnote number should have been (6) which states, "For Poast Plus with Storm in a tank-mixture,
include 1 gal/100 gal of crop oil concentrate."
Dwight Lingenfelter
WEED TOURS QUICKLY APPROACHING
Don't forget to register for the 1996 Weed Tours on July 8 at Landisville and July
9 at Rock Springs. Call Lisa Crytser at 814-865-2543 for additional information.
Bill Curran
CCA CORNER
Using And Interpreting Soil Tests is a program being offered by the Northeastern Branch
of the American Society of Agronomy. It will be presented at Cornell University on
July 17, 1996 from 1:00 to 5:30 pm in Bradfield Hall. Specialists from the University of Delaware, Rutgers University, Penn State and the University of Maine will be leading
the discussions. Topics will include basic principles, philosophies and interpretations
in soil testing; presidedress nitrogen tests; environmental soil testing; and soil testing for regulated metals. There is no charge for the workshop. If you plan
to attend or wish additional information, please notify:
Dr. Shaw Reid
SCAS Department
803 Bradfield Hall
Cornell University
Ithaca, NY 14853
Telephone: 607-255-1722 Ext. - 4540.
This program offers 4.0 CEUs in Soil Fertility.
Elwood Hatley, CCA
PRODUCTION
SLOW FORAGE GROWTH AND DEVELOPMENT
The unusually cool weather this spring has reduced 1st cut forage yields and delayed
development. Early reports indicate that alfalfa yields are slightly lower than
normal. However, with adequate soil moisture and some warmer temperatures you can
expect 2nd harvest yields to be greater than normal. Alfalfa flowering has been as much
as two weeks later this spring than in normal years. Unfortunately, alfalfa quality
has been declining even though it hasn't flowered. This year was one in which the
first alfalfa harvest should have been made based on a calendar date rather than plant development.
Yield of cool-season grasses are also lower this year than in a normal year. This
is probably a combined result of cool temperatures and late spring frosts. Numerous
people have reported that orchardgrass took a pretty hard hit from the frost that
occurred in late May. Again, if the soil moisture is adequate then cool-season grass yields
should rebound and yield slightly more than normal for the 2nd harvest.
Marvin H. Hall
HARVESTING WINTER WHEAT
Harvest time is quickly approaching. Both yield and quality can be affected by harvest
management. It is usually suggested to start harvest when grain moisture reaches
14%. This eliminates the need to artificially dry the grain and eliminates a moisture
dockage when selling directly from the combine. A wheat kernel is mature at 30% moisture.
It will dry at a rate of 2.5% per day from 30 to 20%. From 20 to 14% it will dry
at about 1 percentage point per day under good drying conditions but may require
10 days to drop 1 percentage point under poor conditions. Research at Ohio State University
indicates that during the time wheat is drying from 30 to 14%, yield will drop by
12 pounds per day and bushel weight by 0.25 pound per day. Therefore, each five days
delay in harvest could potentially reduce yield one bushel and test weight 1.25 pounds.
The yield losses result from increased lodging, shattering, and bird and rodent feeding.
Drying and rewetting from rain and dew causes the reduction in test weight.
Wheat can be harvested, without damage to the kernel or affecting milling quality,
once the moisture drops to 20% or lower. Harvesting between 20 and 14% moisture has
the following advantages; increased yield and test weight, reduced combine harvest
loss, maintaining good germination, and earlier seeding of soybean when double cropping.
The disadvantage is the need to artificially dry the grain for proper storage. The
cost of drying, either on the farm or at the elevator, must be compared with the
advantages of early harvesting.
Elwood Hatley, CCA
PEST MANAGEMENT
APHID "HOT-SPOTS" IN WINTER WHEAT
Aphids are showing up in large numbers on the heads of winter wheat in a number of
areas in the southeastern part of the state. There are two different aphids normally
found on winter grains, the corn leaf aphid and the english grain aphid. The corn
leaf aphid is found mainly in the fall, while the english grain aphid is found in the spring.
In all probability its the english grain aphid presently feeding on the heads. The
economic threshold, suggested in the Agronomy Guide, is 100 aphids per foot. Aphids
tend to congregate in areas in the field, therefore scout the total field rather then
the edges or just one or two locations when estimating potential injury. Most years
aphids affect our winter grains by transmitting the barley yellow dwarf virus disease.
In sufficient numbers, they can reduce yield and grain quality when feeding on the
head.
Elwood Hatley, CCA
HERBICIDE PREHARVEST AIDS FOR SMALL GRAINS
As small grain harvest approaches, a herbicide application may be helpful to control
or suppress tall weeds such as bindweed, hemp dogbane, ragweed, velvetleaf, and others
that may interfere with harvesting. This application will help desiccate and control weeds, as well as decrease weed seed production. The following options are available
for use in small grains.
2,4-D. Certain formulations of 2,4-D (namely, low volatile ester formulations) are
labeled for preharvest use in small grains. Check the 2,4-D label for specific use.
Apply with ground equipment to small grains after the hard dough stage and when
weeds are actively growing. The rate range is 1 to 2 pints per acre depending on formulation
and manufacturer. Do not feed treated straw to livestock if this treatment is used.
Roundup. Roundup and Roundup Ultra are labeled for preharvest applications to wheat
only. Apply with ground equipment after the hard dough stage (30% or less grain
moisture) but at least 7 days prior to harvest, and when weeds are actively growing.
Apply 1 to 2 pints per acre. Do not apply to wheat grown for seed. Wheat stubble may
be grazed immediately after harvest.
WATERHEMP: WATCH OUT! - ANOTHER PIGWEED SPECIES
Waterhemp is a problem throughout the Midwest, and it has the potential to become
a problem in our region as well. Waterhemp is a member of the Amaranth (Pigweed)
family and has two known species; tall and common waterhamp. Tall and common waterhemp
are found throughout the Central Plains states; tall waterhemp is reportedly found in
the Northeastern U.S., although we have no confirmed sightings. Tall waterhemp appears
similar to redroot or smooth pigweed in the immature stages, however, they differ
by a few subtle features. Redroot and smooth pigweed have ovate to oval leaves and hairy
leaves and stems giving the surface a rough texture. Smooth pigweed generally has
fewer hairs than redroot. Tall waterhemp has long and narrow leaves and no hairs
on the leaves and stems causing a glossy appearance. Waterhemp also tends to thrive in
wetter soil conditions. Prostrate and tumble pigweed are also common in some areas
of Pennsylvania.
In most situations, waterhemp is controlled along with the other pigweed species in
mixed populations. However, certain biotypes (i.e., organisms with variations of
the same species) of waterhemp have become resistant to ALS-inhibiting herbicides
in some Midwestern states. These ALS herbicides however, still control other pigweeds. Examples
of ALS herbicides include Classic, Pinnacle, Accent, Exceed, Permit, and Pursuit.
As with triazine resistant lambsquarters and pigweed, ALS resistance of waterhemp
is due to the repeated use of the same herbicide mode of action season after season.
If you notice certain pigweed species consistently not being controlled by your herbicide
programs, properly identify the species first. Depending on your control methods
they may either be triazine or ALS resistant biotypes. If herbicide resistance is
suspected use a combinations of cultural, mechanical, and chemical control tactics
to manage the situation. Crop rotation and cultivation can be helpful if applicable.
Otherwise, for corn, preemergence herbicide programs containing atrazine (if species
are not triazine resistant) followed by Banvel/Clarity or 2,4-D can provide good control
of waterhemp. For soybeans, if using an ALS herbicide, tank mix with a diphenyl
ether herbicide such as Cobra, Blazer, Reflex or Stellar. Using Roundup products
in Roundup Ready soybeans is also a viable option for controlling these resistant species.
For additional information on waterhemp identification and control refer to the following
publications: "Pigweed Identification - A Pictorial Guide to the Common Pigweeds
of the Great Plains" is available from Kansas State University CES for about $1.50
each. Call (913) 532-1150 to obtain copies. Also another publication entitled "Waterhemp
Management in Missouri" is available from the University of Missouri CES.
Dwight Lingenfelter
LEAFHOPPER SEASON
Don't get caught off guard, it is time to start scouting for potato leafhopper. Even
though everything else (forage and corn planting, forage harvesting) is running late
this year that doesn't mean that the potato leafhopper will be late! Since this
alfalfa pest migrates in each year on southern jet streams it should arrive about on schedule
(mid June) with rain storms from the south. Scouting for potato leafhopper with
a sweep net is critical because once you can see the leafhopper burn on the leaves
the damage has been done.
Marvin H. Hall
BIRD CONTROL IN CORN
I received a call about bird control in corn. Although this is well out of my field
of expertise, I did make a few calls to find out more information. Greg Roth mentioned
that the Purdue corn IPM manual has a section on bird control, which discusses several cultural approaches to minimizing damage. Some of these options include deeper
planting, use of scarecrow balloons, and spreading seed on the field surface to keep
the birds away from your plants. After a call to the PDA, I also found a company
with registered products. The Avitrol Corporation (Telephone 918-622-7763, 7644 East 46th
St., Suite 514, Tulsa, OK 74145), produces several products, all with the name Avitrol.
They vary in regards to whether the active ingredient is present in a powder, mixed with cracked corn, or present with whole corn. Applying this type of product is
very different from other pesticides, including pre-baiting procedures to observe
flocking behavior. Read the label carefully. Contact the above telephone number
for full labels.
CORN INSECTS
Corn Rootworm Should be Hatching. Corn rootworm hatches at around 600 degree-days.
We are probably well into this point in the warmer area of PA, and most other areas
should reach this point shortly. For those of you using a post-emergence control
strategy such as Furadan 4F, the most optimum time is early in the hatching period.
Cutworm Problems Continue. Heavy clipping damage was seen in Centre County last week.
Problems may continue for another week or two.
Large Corn Borer Flights. Large first generation corn borer flights were observed
from Centre to York Counties last week. It might be a good idea to scout for first
generation damage in the next two weeks. See the last newsletter for more details.
Steve Spangler & Dennis Calvin
AGENT OBSERVATIONS
Between raindrops producers managed to plant corn and beans, harvest alfalfa and apply
fungicides on wheat and barley all at the same time. Weeds are starting to push;
foxtail around 4-6 inches, and broadleaf weeds 2-4 inches. Pea aphids and weevils
are working on alfalfa along with a few leaf hoppers. I suspect most leafhoppers will
be here on this last storm. Early corn looked yellow until recently when a warm
front brought much needed heat. The forth leaf has created a collar with the fifth
leaf close behind. Late corn is at 2 leaf stage. I saw my first fire fly and suspect rootworms
will be starting to show damage soon.
Beans are growing well with the warm weather. Most acreage has the first leaves expanded
and some with the first trifoliate out. Wheat is ripening and barley is almost finished
filling the grain.
Del Voight
Lebanon County
Early week rains provided timely moisture to rapidly developing crops. Soil moisture
levels were less than adequate in upper Dauphin County. Conditions in Lower Dauphin
were better due to sporatic showers. Majority of acreage is planted. Early corn
is in the 6-7 LS, beans in the first trifoliate stage.
Winter wheat stands are filling grain. No appreciable disease conditions. Producers
are anticipating a good crop.
Sweet corn monitoring traps indicate heavy flights of corn borer moths.
Second cutting hay crops look well. Early cut stands were slow to initiate regrowth
in many winter weakened stands. Many older stands have been rotated out of production
one or two years earlier than expected this spring.
Paul Craig
Dauphin County
Crops in southwest PA are variable at this time(6/12/96). After a very long wait for
a suitable planting season, the following applies:
Winter grains - The barley crop looks good. Good seed fill and crop maturation is
on schedule. Winter wheat is variable. Significant portions of fields suffered losses
due to the heavy March and April rains.
Spring grains - Early planted oats is maturing properly, but there are some problems
with cereal leaf beetle. Most of the oats crop was planted very late, some of which
was planted the third week of May.
Corn - Only about 10 percent of the corn was planted by May 27. Serious planting didn't
begin until May 30 and continued through June 8. Significantly more acreage than
normal was planted using no-till methods. Good germination and growth has occurred
so far with very little insect or disease infestation.
Forage crops - Hay harvest is late. Some dairymen made hay crop silage the week of
May 20. Although challenging, good quality hay crops were ensiled. This week (June
10) many farmers are mowing hay, but daily showers are prohibiting any progress.
Some localized areas are very wet.
I was able to established two sub-surface tillage plots, one of which is in a valley
on fields that are perennially planted to conventionally tilled corn silage. During
May I had the opportunity to talk with the cooperator about the improved drainage
as a result of the sub-soiling. He commented on the significant difference observed in
favor of the sub-soiled areas of the fields.
Don Fretts
Fayette County
Corn - Local crop technicians are indicating thin corn stands (70-80%) for corn planted
2-3 weeks later than normal. Soil that is being planted no till is very hard this
year. Not hearing much about any serious weed or insect problems or herbicide failures. We have gotten a few calls about farmers spraying in windy conditions and causing
some off-target problems.
Soybeans - Still some soybeans to be planted. Earlier planted stands look reasonable.
Again, not hearing much at all about weed problems or herbicide problems. There
will probably be some crusting problems on some soils because of recent hard rains
and potentially hot weather. Some erosion problems on tilled fields.
Small Grains - Wheat is doing well on soils where it withstood the winter. Only a
few reports of disease. So far it looks like grain is developing normally. Too
little oats or barley around to even comment on.
Hay - Local crop technician reporting alfalfa yields are good. Windrows in some areas
looking pretty meager and a few reports of lower then normal first cutting yields.
Some of these probably on areas where the crop took a beating over winter. First
cutting of alfalfa mostly complete. No reports of weevil problems in alfalfa. There
is still a lot of grass hay to be harvested.
Pasture - Pasture swards have generally grown slower than normal this spring. However,
recent warmer weather and ample moisture have brought on growth (and seedheads) in
a hurry. Most rotational graziers have been through several rotations by now. Some
beef graziers who don't put up much, if any, hay or haylage are still wading through
primary growth.
Dave Hartman
Columbia, Montour, Upper Northumberland Counties
William S. Curran
Associate Professor Weed Science
email: wsc2@psu.edu
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Website Address: http://fcn.agronomy.psu.edu/