Field Crop News

Website Address: http://fcn.agronomy.psu.edu/

June 24, 2008 Vol. 08:16

IN THIS ISSUE:

Sorry, no “Weather Outlook” this week, look for it to return to this newsletter next week.
Small Grain Preharvest Aids
Wheat and Barley Harvest Management
Selecting Insect Control Materials in Field Crops
Management Options for Deer Herd Impacts
Stunted Timothy in Eastern PA
Penn State Agronomic Diagnostic Clinic

Small Grain Preharvest Aids — Bill Curran and Dwight Lingenfelter, PSU Weed Science (some comments adapted from R. K. Zollinger, NDSU Extension Weed Specialist)

Most of the barley has been harvested in the Southeast and is starting to come off in other parts of the state and wheat harvest is quickly approaching. Below is an overview of a few considerations and some options to consider for preharvest weed control in small grains:

This may be a great opportunity to control perennial weeds prior to double crop soybean or prior to establishment of a late summer hay crop. Although late summer is still the best time for perennial weed control, this is certainly better than early summer applications and may help fit into certain crop rotations.
Don’t expect miracles with harvest aids. It is still easier to control smaller annual weeds (<4 inches tall), than larger ones (2–3 feet). In some cases, the lower portions of the weeds may still be green and unaffected.
It takes time to bring down a large weed. It usually requires about a week or more to obtain good control or dry—down of some weeds. This time may be increased if cool/wet weather conditions exist. With exception of Aim, the small grain herbicides labeled for preharvest are systemic and slower acting than a contact herbicide.
Harvest aids are meant to help facilitate harvest and reduce harvest loss. Any yield loss likely has already occurred from weed competition throughout the growing season. Also any weed seeds produced will contribute to next year’s weed problems.
Herbicide drift from these applications at this time of year will cause injury/death to sensitive crops/plants in surrounding areas.
Adhere to all restrictions regarding grazing and feeding of straw for each of these products.

2,4-D
Some formulations of 2,4–D ester and amine are labeled for preharvest applications in wheat, barley, oat, and rye. (Only certain 2,4–D products have all of these small grains listed on their label under preharvest, so consult the specific label before application.) Use 1 to 2 pints per acre depending on the product. Applications should be made after the small grain is in the hard—dough stage. Do not apply to small grains with a legume underseeding. If a preharvest application of 2,4–D ester is made, double—crop soybeans can be planted 7 days later for 1 pint or 30 days for 2 pints.

Glyphosate
Glyphosate products may be applied to wheat and feed barley after the hard dough stage of grain (30% or less grain moisture) and at least 7 days before harvest. Do not apply more than 0.75 lb ae (i.e., 22 fl oz/acre Roundup Original Max/PowerMax or 1 quart/acre 4S products), and do not treat wheat being grown for seed as a reduction in germination or vigor may occur. Additionally, do not apply to wheat with a legume underseeding. There are no double—crop soybean planting restrictions if glyphosate is used as a preharvest treatment.

Clarity or Banvel
Clarity or Banvel (dicamba) can be used at 8 fluid ounces per acre preharvest when wheat and barley is in the hard dough stage and the green color is gone from the nodes (joints) of the stem. Apply at least 7 days prior to harvest. Do not use if legumes are underseeded. Do not use preharvest—treated wheat for seed unless a germination test is performed on the seed with an acceptable result of 95% germination or better. Although the Clarity and Banvel labels allow double crop soybeans following their application (with adequate rainfall and time), the potential for injury may preclude this use. See a Clarity or Banvel label for specific guidelines on rotational crops.

Aim
Aim may be applied to barley, oats, triticale, and wheat to defoliate and/or desiccate certain broadleaf weeds (such as annual morningglory, pigweed, and velvetleaf). Application should be made when the crop is mature and the grain has begun to dry down. Apply 1 to 2 fl. oz/acre in a minimum of 10 gallons of water for ground applications. Include 0.25% NIS or 1 to 2% MSO or COC in the spray mixture and good coverage of the weeds is essential for satisfactory performance. AMS (2–4 lb/acre) or UAN 2–4 gallon/100 gallon) may also be included. Rage D—Tech is a mixture of Aim (carfentrazone) plus 2,4–D ester and may be used as a harvest aid in wheat, barley, oats, and rye after the hard dough stage. Apply Rage D—Tech at 16 to 32 fl. oz/acre and include appropriate adjuvants as previously described for Aim.

Other herbicides
Other herbicides such as Gramoxone Inteon, Harmony Extra, Buctril, etc. are not labeled for use in small grains as a preharvest aid.

Wheat and Barley Harvest Management — Greg Roth and Del Voight, Grain Crop Management

Barley harvest is underway and wheat will begin soon throughout the state. This year’s crop is one of the most valuable ever harvested and there is more potential for double cropping than ever before. Careful management is critical to maximize the potential of both the small grain and the succeeding soybean crop. Try to monitor grain moisture as the crop dries down and consider starting the harvest near 18%. This may require drying the wheat with air, but it favors high test weight, lower combine losses and perhaps 3–5 day earlier soybean planting. And, with delayed soybean planting reducing yields by approximately one bushel per day, the earliest planting possible is preferred. Once combining begins, pay careful attention to harvest losses. As a general rule, an average of 20 kernels of wheat or 14 kernels of barley per square foot represent one bushel per acre. Often, the kernels are not uniformly distributed behind the combine, which makes it difficult to assess losses. One method (adapted from NDSU) to simplify this is as follows:

Count the kernels left directly behind the rear of the combine in several square foot areas. Determine the average (A).
Count the kernels already in the field (beside the windrow) due to shatter and cutter bar. Determine the average (B).
Subtract (B) from (A).
Divide the results of step 3 by the ratio: (Width of head cut (ft)) / (Width of combine cylinder (ft)).
Divide the result of step 4 by the number of kernels equivalent to one bushel per acre loss (wheat=20, barley=14 and oats= 10). This is the approximate machinery loss in bushels per acre.
To find total loss, add the count in (B) to the result in step 4. This is the total seed count from shatter, cutter bar and machine losses.
Divide the total seed count of step 6 by the number of kernels for the particular crop for one bushel per acre loss (Table 20). This will give the approximate total loss in bushels per acre.
For a percentage loss, divide the loss in Step 7 (loss in bushels per acre) by the total yield (harvest yield plus loss) in bushels per acre for the field.

[(Loss)/(Harvest Yield Plus Loss)] X 100 = % loss

Example: A 20 foot combine head is used in a wheat field yielding 52 bu/acre, and the combine has a cylinder 4 feet wide.

A = kernels per square foot counted directly behind the combine = 59 kernels per square foot.
B = Kernels per square foot to the side of the windrow = 4 kernels per square foot.
B – A = 59 – 4 = 55 kernels per square foot.
Ratio: width of cut (ft) / width of cylinder (ft) = 20/4 = 5. Divide 55 by 5 = 11 kernels per square foot.
Divide 11 by 20 (wheat) = .55 bu/acre = machine loss.
Total loss = “B” plus answer in Step 4. = 4 + 11 = 15 kernels/ft₂
Divide 15 by 20 (Table 1) = .75 bu/acre = total loss
% total loss = answer in Step 7 divided by harvest yield plus total loss

% loss = [loss / harvest Yield Plus loss] X 100

% loss = [.75 / (52 + .75)] X 100 = 1.8%

Normally it is difficult to reduce losses to less than 1–2 %. Excessive losses are often due to delayed harvest, driving too fast, improper combine set-up. New combines have grain monitors that monitor harvest losses and can give you the ability to track losses. Now is the time to plan for a profitable wheat harvest and double crop planting.

Selecting Insect Control Materials in Field Crops — Del Voight, Lebanon County Extension

As we move into the critical period of crop growth many reports across the state dealing with insect pests have been called into local Extension Offices. Potato leafhoppers in alfalfa, bean leaf beetles and numerous Lepidoptera insects and most recently, True armyworms remain active and by the time they are complete there will be fall armyworm activity. Moreover, if it stays dry, spider mites will begin showing up in fields. If that is not all, the beetles (rootworm to Japanese beetles) will emerge and begin feeding. Selecting an insecticide can be difficult since many options exist. This article will outline some basic selection parameters.

There are three main classes of insecticides widely used in the state: Pyrethriods, carbamates, and organophosphates. A forth would be the nicotenoid compounds that are being used as seed treatments and for insect control in vegetable crops. Further within each class there are distinct differences in cost. The armyworm situations we are witnessing currently, as well as the weevil scenario this spring, are great examples of a selection that may be costly or cost very little. When a grower has a threshold of a pest and an insecticide is the best option, then our job in Extension is to educate the grower about all the options. Many times in the industry supply chain; however, warehousing and delivery in a timely manner can become an important issue. For example, Table 1 illustrates the partial list of products listed for control of alfalfa weevils in alfalfa. A grower could choose to pay from a low of $1.84/acre to a high of $13.35 — a greater than a ten dollar difference per acre. The cost of a pest management tactic must come into play but this cannot be at the cost of controlling the pest. If all criteria are met then saving money is the frugal option.

The pros and cons of an insecticide really trace back to the class of chemistry it is derived from and the technologies used to formulate the chemistry. For single pest control in many cases the pyrethroids (Warrior, Pounce, Baythroid) do a great job in controlling the pest. Numerous options are available and the costs also vary widely between materials. Further there are a plethora of generics available under different names and marketed by different suppliers. By varying the rates of pyrethroids different pests and different sizes of pests may be managed or controlled. What this means is if you decide to use these products you will need to adjust the rate according to the size and type of pest you seek to control. Sunlight is the enemy of pyrethroids. New formulations prevent loss to sunlight and therefore the residual control is maintained; however, efficacy studies of the initial knockdown do not vary widely between products. Bees and ladybugs as well as ground beetles suffer greatly with pyrethroid applications so an assessment of the beneficials is required to best manage the pest and not to eliminate the balance in the field of pest to predator. Most labels have a discussion and cautions within this subject area.

In multi-pest situations, the carbamate and organophosphate classes have wide-spectrum activity. While they also impact beneficials they normally will do a great job of controlling several pest complexes and, at normal use rates, control varying sizes of insects. Combinations of pyrethroids and organophosphates such as Cobalt, recently labeled by Dow, have combined the quick knock down of pyrethroids with the broad-spectrum activity of the organophosphates. So as you make pest management decisions, first base it upon the real need to treat, followed by cost, control of the pest, the proper rate for the pest and its impact on beneficial insects.

One final consideration is tank mix compatibility. This is largely dependent upon the formulation and growers should consult the label to determine tank mix partners and potential antagonism with herbicides. As always it is best to consult the label, read and follow the directions.

Table 1. Insecticides labeled for alfalfa weevil.
Insecticide	Rates Per Acre low/high	Harvest interval (days)	Cost/Acre Jan 2008 Pricing low/high
Ambush 2E	6.4-12.8 ounces	0-14	2.94-5.87
Baythroid XL	1.6 - 2.8 ounces	7	2.68-4.71
Furadan 4F	0.5-2 pints	7-28v	4-16
Lannate LV	3 pints	0	20.55
Lorsban 4E	1-2 pints	14-21	3.34-6.68
Penncap-M	2-3 pints	15	?????
Pounce 3.2EC	4-8 ounces	0-14	1.84-3.67
Sevin XLR+	3 pints	7	9.56
Warrior 1T/Proaxis	2.56-3.84 ounces	7	3.78-4.34
Mustang Max	2.24 to 4.0 ounces	3	????
Cobalt	19-38 ounce	7-14	6.67-13.35

Management Options for Deer Herd Impacts — Mark Madden, Sullivan County Extension

Based on an annual survey administered at winter crop meetings over the last several years, most crop producers in Bradford County believe that the local deer herd has been reduced and crop damage is currently within tolerable levels. This trend isn’t noted throughout the commonwealth and in some locations producers are still hampered by the damage caused by a locally excessive deer herd.

Recognizing the damage to farm crops can have significant effects on production, the Pennsylvania Game Commission has been responsive to the concerns of farmers and other landowners who wish to reduce the impacts of high deer populations. A summary of the various programs available through the Pennsylvania Game commission is available on their website or with a control—click on the following hyperlink: Agricultural Deer Control PDF. A synopsis of the alternatives available to help landowners achieve deer densities consistent with their land use goals is provided below.

Destruction of Agricultural Protection

Everyone who earns their livelihood farming has the legal right to kill game (except threatened or endangered species) they SEE destroying their cultivated crops on their farm.
May keep one carcass for food IF THE LAND IS OPEN TO PUBLIC HUNTING and the head and hide must be relinquished to the PGC. Another deer maybe destroyed and kept for consumption once the previous kill has been entirely consumed.

Agricultural Deer Control Permits (Red Tags)

Usually implemented where the greatest need for deer control is required.
Applicant landowners must have at least two years participation in the PGC’s public access program.
Farmer recruits licensed Pennsylvania resident hunters not associated with the farm and issues them a subpermit to take deer. No fee maybe charged. The permit is valid from February 1 to September 28^th excluding Sundays and from a period in mid-May to the end of June or July depending on the crops grown.
Deer can be consumed by the hunter or donated to an established food bank.
Farmer may restrict the type of firearm or bow that can used.
Application period is open year-round.

Deer Management Assistance Program (DMAP)

Private properties are eligible where no fee is charged for hunting.
APPLICATION DEADLINE is JULY 1^st.
Landowner is issued DMAP Harvest Permit Applications (Coupons) to distribute to licensed hunters. Resident and non-resident hunters use the coupon to apply with the appropriate fee for the harvest permit from the PGC. A hunter is eligible for two permits per property and may take only antlerless deer.
Farmer can opt to post the availability of DMAP coupons for their lands on the PGC website or they can keep this information private and offer coupons to hunters of their choosing.
Coupons are issued at a rate of one per five acres of affected crop land and one for every 50 acres of woodland (or other land types). An approved deer management plan may provide for additional coupons.
Landowner may not charge or accept any contribution in exchange for coupons.
Landowner must provide maps of the property to permit holders and the property boundaries must be clearly marked.
Hunters MUST report to the PGC regardless of their success.
The DMAP application can be downloaded by control-clicking: DMAP Landowner Application.

Contact your regional Pennsylvania Game Commission office for additional information. The contact information is listed with the DMAP Landowner Application referenced above.

Stunted Timothy in Eastern PA — Andrew Frankenfield, Montgomery County Extension and Dwane Miller, Schuylkill County Extension

Over the past few weeks several farmers in Schuylkill and northern Lehigh Counties have reported timothy stands that look very weak and are performing poorly. These fields are not short on fertility. These fields have been fertilized and Sevin XLR Plus has been applied for timothy mites. Some had herbicide applications of Milestone, 2,4-D, and/or Banvel. Some samples have shown the presence of two-spotted spider mites and aphids. A common feature seems to be the timothy stand followed wheat in the rotation. Some of the roots appear to be rotted. Leaves show a spotted yellow appearance then turn prematurely brown. Growers complain about severe yield reductions in effected fields. Samples have been shipped to both PSU and PDA Plant Disease Labs for further analysis but if you know of any similar situations on your farm, or a client’s farm, your county extension educator with agronomic program responsibility would like to know about it.

Penn State Agronomic Diagnostic Clinic — Dwight Lingenfelter, PSU CMEG

All interested people are invited and encouraged to attend the Penn State Agronomic Field Diagnostic Clinics held on July 22 and 23, 2008 from 9am – 4:30pm at the Penn State Agronomy Research Farm near Rock Springs, PA. Each day offers the same agenda.

This year’s Clinic will include sessions on:

Soil genesis and inherent properties related to crop production and soil management
Soil quality and effects of cover crop roots
Corn and soybean disease update
Pest management using seed traits and seed treatments
Herbicide mode of action and resistant weeds

(CCA and pesticide credits will be available.)

Visit http://cropsoil.psu.edu/extension/clinic.cfm for more information about each topic.

The cost is $60/person. ($80 after July 16)

To register, please visit: http://cropsoil.psu.edu/extension/clinic.cfm and use the “on-line” registration system or complete the hard-copy form and fax or mail it. Phone-in and email registrations are discouraged. Credit card payments will be accepted. (Note: we are using a new registration system this year, so please make sure to complete the necessary procedure.)

If you have questions about the Clinic please contact Dwight Lingenfelter at 814–865–2242.

We look forward to seeing you at this year’s Clinic!

Contributors: Dept. Crop & Soil Science: Marvin Hall, Ron Hoover, Bill Curran, Sjoerd Duiker, Dwight Lingenfelter, and Greg Roth. Extension Educators: Andrew Frankenfield (Montgomery), Kevin Fry (Armstrong), Mena Hautau (Berks), Joel Hunter (Crawford), John Rowehl (York), Del Voight (Lebanon), Susan Alexander (Jefferson) and Mark Madden (Sullivan).

Editor: Mark Madden

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