CMEG Crop Management Extension Group

Field Crop News

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

May 8, 2007    Vol. 07:10

IN THIS ISSUE:

Weather Outlook — Paul Knight, Pennsylvania State Climatologist

After a very cool, moist April, odds favor slightly below average temperatures and generally below normal rainfall during May. As summer approaches, this pattern should yield to much warmer weather in the Northeast with near to below normal rainfall. Week One (May 9–15): The pristine conditions will mellow into hazier skies and higher humidity later Wednesday in the western sections and statewide on Thursday. Expect a scattering of thundershowers — mainly in the northern half of Pennsylvania Thursday afternoon and night. A new push of cooler, dry air from Canada will arrive for the weekend and will quickly moderate into a rather warm air mass by next Tuesday. Statewide rainfall: 0.10–0.60” (best chance next Tuesday) Week Two (May 16–22): More cool air will stream into the region from the northwest on the 15–16th, but the front may stall for a time along the coast raising the chances of more showers in eastern sections. A generally dry and comfortably cool period is likely from May 16–18th. As more cool air approaches, there are signs that a front will stall across the region between May 19–21 promoting below average temperatures and what may be the wettest period of the month.

Statewide rainfall: 0.50–2.00” (best chance May 19–20).

Watch Your Soybean Seed Drop Rates! Ron Hoover, Coordinator of On—Farm Research, Crop and Soil Sciences

A team of extension educators and specialists are working with me in evaluating the benefits to soybean stands when a seed treatment is used. The first step in the process is to know how many soy seeds are being dropped by the planter or drill. Recent experiences in working with some cooperating farmers on this project indicate that populations can vary slightly or greatly from the table values listed in the operator’s manual for the planter or drill. One calibration on a newer planter with splitter units that were equipped with a brush—type metering mechanism found drop rates that were 6 to 9 percent higher (11,000 to 15,000 seeds/acre) than values listed in the operator’s manual. On an older brushless planter, where the seeding rates are shown in pounds per acre, our goal was 53 lbs/ac. This way of calibrating was made even more complex as there is no consideration given by the manufacturer for the size of seed being planted. Our seed size is 3125 seeds per pound, which correlates to a dropped population of 167,000. However, when a calibration run with the planter was conducted, we found the drop to be nearly 203,000! The difference of 36,000 represents an overage of nearly 22 percent. The morale of the story is that with soybean seed costs representing an increasing fraction of the total cost of growing the crop, one needs to do some checking to ensure that planting equipment is dropping enough seed but not too many. Consult the PSU Agronomy Guide to determine the population that best matches your situation.

Assessing Grub Populations and Spring Management Ideas — Del Voight, Regional Field Crop Pest Management Educator

Going into last fall I received numerous calls (about 20 a day) on white grub and Green June Beetle Grub activity that severely injured and in many cases killed sod, pasture, hay fields, and small grains. A grub is the larval stage of numerous beetles. (Japanese, June, Chafers) that we see flying around in late July). The grub’s stage that injures crops the most is under the soil or at the surface.

A fact sheet is available by calling 270–4391 or emailing njs14@psu.edu that gives the identification of grubs. They are C shaped and small about a half inch long with three sets of legs in the front and are white in color with a tan head. There are several species but simply count the total number at this point. In most cases thresholds for grubs will be generalized to the number of grubs per foot so species identification is needed in two cases. The first is if a pesticide fails to determine if one is more resistant to a pesticide. The other case is important with Green June Beetle (GJB) grubs. The smaller white grubs typically lay eggs in late July and spend there whole life in the soil eating roots and other organic material. Treatment and management require products to be applied just prior to a rain event to water the pesticide into the soil to where the grubs are feeding. The GJB grubs are large about 2 inches long and feed primarily at/on the soil surface and come up at night to feed. This pest requires a pesticide for control to applied and put on the surface of the soil

To scout for grubs a shovel and a piece of paper are required. First determine where to scout. Fields with sod/pasture or hay would be the first fields to check. Then check annual cropped fields that had soybeans in them or BMR sorghum or late silked corn. One will need to move into the field and plan to take 5 samplings (a piece of paper or notepad will work with a pencil to write down your findings at each of the 5 locations) from random spots in the field. Using the shovel one will need to make a one square foot square and remove the soil down to about 8 inches. Once the soil is removed move the soil with the shovel and look for the presence of the grubs (slow down and really look into the soil and you will easily see the grubs). Count the number of grubs and note it on a pad. At the end tally up the five locations and divide the total by 5 to come to an average. This will assist you in referring to the Agronomy Guide for thresholds and management options. Here are some common thresholds to consider.

In pastures if you have two or more large grubs (that would be the GJB larvae about 2 inches long) then treatments are necessary and the cost of treatment will pay for itself with increase yield. Sevin XLR is the only product labeled for GJB control in pastures. I found the product highly effective in control. (Be sure they are active when applications are made and not more than a ¼ in of rain are expected in a week). If one finds 6–8 grubs per square foot of small white grubs then treatment is necessary. Again Sevin XLR is the only product labeled however it needs to be applied and rained in to be effective. I have found mixed results with this product. But it is the only one labeled in the pasture. In home lawns there are several products available for control that are much more effective and that would be content for another article.

In Corn the threshold is one grub (the small species about ½ inch long per foot. Since the GJB typically are not found in corn fields there are not any thresholds established in Pa. Heavy populations are being reported in corn following sod and double crop soybeans. Lighter populations are observed in full season beans from last year and few are being found in corn following corn. For light populations (following full season beans)Poncho 1250 should provide control. If more than 1 per foot is noted then an additional insecticide may be required to control the pest. Lorsban 15 G has a half rate label in combination with Poncho or Cruiser at the high rate. Capture has a label for the 3.8 ounce per acre in the starter on the seed in combination with the high rate of Poncho or Cruiser. Force is recommended at full rate in the furrow with the seed. In the low rate of seed treatment are used then the full rates of labeled products is the best option. This is particularly important when populations reach 6 grubs per foot after double crop beans or sod.

In Soybeans, the threshold is one grub (the small species about ½ inch long per foot. Since the GJB typically are not found in tilled soybean fields there are not any thresholds established in Pa. For light populations Cruiser Max should provide control. If more than 1 per foot is noted then an additional insecticide may be required to control the pest. This is particularly important when populations reach 6 grubs per foot. The addition of Lorsban 4E at burn down in no till timed to just before a rain also is an option to reduce heavily infested fields.

By getting out in the field now one may avoid the damage caused by this pest. Now is the time to see how many survived winter and begin to plan a pest management strategy.

Roundup Ready Alfalfa Injunction Stands — Bill Curran, PSU Weed Specialist

The U.S. District Court for the Northern District of California has upheld its decision that the USDA did not adequately follow procedural requirements by the National Environmental Policy Act before deregulating Roundup Ready alfalfa. Under the Plant Protection Act the court maintained that prior to deregulation of Roundup Ready alfalfa, the USDA would have to prepare an environmental impact statement in place of the environmental assessment that was completed. Roundup Ready alfalfa that was planted by March 30, 2007 can still be grown, harvested and sold as forage.

The injunction was issued by the court following a lawsuit brought by the Center for Food Safety and others against the USDA. Despite previous acceptance that Roundup Ready alfalfa posed no harm to humans and livestock, the court upheld its decision that the USDA did not adequately follow procedural requirements as detailed by the National Environmental Policy Act before deregulating Roundup Ready alfalfa. One of the plaintiffs’ claims against Roundup Ready alfalfa was that it would cross—pollinate with organic or conventional alfalfa varieties. Alfalfa seed production fields rely on bees for pollination, so movement of bees between seed production fields is an issue for the environmental impact assessment.

To support its argument that growers should have continued access to the technology, Monsanto presented extensive regulatory and environmental studies on Roundup Ready alfalfa. It also described successful stewardship practices that allow the coexistence of organic, conventional and Roundup Ready alfalfa. Monsanto Company petitioned the court to become a party in the case to defend grower choice to use the technology. The company is reviewing its options, including the possibility of an appeal of the court’s decision. At this point, it is unclear when this case will be resolved or what the outcome might be, but for now, new seedings of Roundup Ready alfalfa are on hold until further notice.

Glyphosate Preharvest Options — Bill Curran, PSU Weed Specialist

The glyphosate label continues to expand with additional use options. In our weekly Crop Management Extension Group teleconference, several new options were discussed this morning and unless you spend time reviewing labels (and even if you do), you may have missed some of this. Remember, NOT all glyphosate products allow the same use options, so check individual product labels before using a product. In particular, Monsanto branded glyphosate (i.e. Roundup) appears to have the broadest label use options, but competitor products (i.e. Touchdown, Glyphomax, etc.) will also likely have these uses added over time.

For the purpose of today’s article, I am specifically discussing “Roundup” branded glyphosate.

This use does not include cereal rye or other small grains harvested for forage.

Delayed Pre/Early Post Herbicide Considerations for Corn — Dwight Lingenfelter, PSU Weed Science

If the corn is already coming up and you didn’t get a chance to apply a pre herbicide, have no fear, because there is still an opportunity to apply certain soil residual products. A number of residual herbicides can be applied after planting up until corn and weeds reach a certain size or growth stage. The greatest risk of failure comes with trying to control annual grasses such as foxtail and panicum after they emerge. However, several products are available to control emerged grasses (e.g., Accent, Basis, Celebrity Plus, Equip, Impact, Option, Steadfast (ATZ), Stout, glyphosate on Roundup Ready corn only, and Liberty on LibertyLink/GR corn.) In most cases, these post—grass herbicides can be tank—mixed with the residual products if some annual grasses have already emerged. (See the herbicide label for additional information on tank—mixing— WWW.CDMS.NET or WWW.GREENBOOK.NET ). For most products, do not apply in a liquid fertilizer carrier if corn has emerged or injury may occur. Maximum corn and weed sizes vary for delayed pre/early post herbicide applications in corn depending on the product. Herbicides such as Balance Pro, Radius, and Princep must be applied before corn emergence. Other herbicides such as Bicep II Magnum, Bullet, Dual II Magnum, and Stalwart Xtra, Trizmet II can be applied to corn up to 5 inches tall. Acetochlor—containing products such as Degree (Xtra), Harness (Xtra), FulTime, Keystone (LA), and Volley Atz can be applied to corn up to 11 inches tall. Herbicides such as Atrazine, Lumax, Lexar, Guardsman Max, and Resolve can be applied to corn up to 12 inches tall. And finally, Prowl H2O can be applied to 30 inch tall corn or less. Keep in mind, when tank—mixing with other pesticides follow the most restrictive product label. For a listing of additional herbicides and maximum corn heights and information on maximum weeds sizes for these products pleaser refer to Table 2–2–12 in the Penn State Agronomy Guide or online at http://agguide.agronomy.psu.edu/pm/sec2/table2–2–12.cfm.

Burcucumber — Two Step Management — H Grant Troop, CPAg/CCA, Regional No Till Coordinator, Penn State/Lebanon County Extension Office

Burcucumber is a perennial problem in many areas of the state even though it is an annual plant. Managing this climbing weed presents a serious challenge. No—tilling can help as this will keep seeds near the soil surface where they will germinate in a relatively narrow window versus seeds in tilled fields that may emerge over several months from varying depths. (1–6”) in the soil.

Chemical control is also a tricky matter. The best approach is to give burcucumber as much of what it doesn’t like as labeled. In the two step approach use a chloracetemide/atrazine pre—mix eg.( Guardsman Max, Keystone, Bicep II Magnum, Harness Xtra) and tank mix with Balance Pro at 1.5–2.0 oz. per/acre for severe infestations. Try to get 1.5–1.6 quart of total atrazine per acre applied in this pre emergence application. So step one is a pre emergence application of herbicide.

Step two is a post emergence herbicide application in which the spray material mix will change according to plant height and burcucumber infestation severity. The following is a per acre general spray material selection guideline by corn height:

4"–24" Spirit 1 oz. + Status 5 oz. Or Impact 0.75 oz.
4"–36" Northstar @ 5 oz.
4"–pretassel Beacon @ 0.38 oz. + Impact 0.75 oz.
4"–45 days preharvest Impact @ .075 oz.

Notes:
a) Check labels for when to apply using drop nozzles.
b) May add atrazine to the above mixes only until 12" tall corn.
c) Impact may follow Balance Pro pre at 2 oz. or less only. Impact is not labeled to follow Callisto containing herbicides (eg. Lumax, Lexar).

Taking First Cutting of Alfalfa Early — Marvin Hall, PSU Forage Specialist

Alfalfa is starting to show some buds in the southern part of the Pennsylvania but it is still shorter than in most years. Producers are asking about harvesting now for top quality or waiting for it to get a little more height (more yield) before taking that first cut.

In 2005, a joint project was completed in Idaho, Wisconsin and Pennsylvania to answer that question. We seeded three different alfalfa varieties and harvested them over a 3–yr period. There were no differences among varieties or years so data were combined. Delaying harvest in the spring increased yield by only 290 lb/a/day but decreased RFV (relative forage quality) by 5 units each day and NDFD (neutral detergent fiber digestibility) by 0.2 percentage units each day.

Change in yield and NDFD for each day harvest is delayed in Pennsylvania.
Harvest DM Yield
(lb/a/day)		 RFQ
(units/day)		 NDFD
(%/day)		 lb/a forage increase per
% decrease in NDFD
Spring 290 5 -0.2 1050
Early-summer 60 5 -0.7 80
Mid-summer 100 4 -0.2 530
Late-summer 40 4 -0.4 80

Taking spring harvest a little early will provide optimum quality, a good opportunity to make some forage before the rains arrive over the weekend, and possible crash weevil populations in the field. The decrease in yield could be regained in the 2nd harvest if there is sufficient moisture to keep the alfalfa rapidly growing before the temperatures get too high.

Editor’s note: Many of our producers rely on intensively managed grass rather than alfalfa for forage and there are a couple of important differences between alfalfa and grass when it comes to harvesting quality first cutting forages. The “ideal NDF” value for alfalfa is considered to be 40 % but for grasses it is 50 to 55%. In addition, the harvest window for optimum quality tends to be smaller (or closes sooner) than for alfalfa. Paying attention to forage quality as related to the timing of first cutting is critical and can be a real challenge because of all of the on—farm activities and demands during the spring crunch. For an article on a project that looked at NDF of alfalfa and grasses and how they changed over time one season check out: http://cnydairylc.cce.cornell.edu/newsletters/may12005.pdf

Upcoming Events:

Cover Crop Research and Management Summit
June 5, 2007
Tuesday, 9:30am–3:30pm
Penn State Rock Springs Agronomy Farm, Centre Co.
Cost: $10
Lunch and handouts will be provided.

During this cover crop management field day, you will have an opportunity to see and hear about the latest cover crop research at Penn State as well as observe first hand some of the tools and practices being tested. Topics will include choosing cover crops based on farming goals, how to grow or capture nutrients and the importance of carbon and nitrogen, improving soil quality, controlling cover crops including using rollers/crimpers and how cover crops can help control weeds.

This tour will be given by a distinguished group of Penn State researchers from across the college who have cutting edge projects underway focused on cover crops. In addition, Rodale Institute staff will be on hand to share their management experience in organic farming systems. Certified Crop Advisor CEU’s will be available at this event.

You must pre register with Lisa Crytser at Penn State to ensure you have a spot at lunch and on the wagons. Please pre—register by May 30, 2007 by phone (814-865-2543) or email (lac8@psu.edu).

American Forage and Grassland Conference
June 24–26 — in State College
For more information check out http://www.afgc.org/mc/page.do?sitePageId=42837&orgId=afgc

Agronomic Weed Management Research Tour at Penn State
July 10, 2007
Tuesday, 9:00–12:00 noon
Penn State Rock Springs Agronomy Farm, Centre Co.
Cost: $15
Lunch and handouts will be provided.

A number of experiments will be showcased and available for viewing including many of the new corn and soybean herbicide programs plus the latest information on herbicide resistance, cover cropping and weed management research. Certified Crop Advisor CEU’s will be available at this event.

You must pre register with Lisa Crytser at Penn State to ensure you have a spot at lunch and on the wagons. Please pre—register by July 3, 2007 by phone (814-865-2543) or email (lac8@psu.edu).

2007 Penn State Agronomic Field Diagnostic Clinic — July 24 and 25
July 24 and 25
Penn State Rock Springs Agronomy Farm, Centre Co.

The dates and topics for our annual Diagnostic Clinic have been set. As in the past, the Clinic is a one—day event conducted at the Penn State Agronomy Research Farm near Rock Springs, PA. This year’s Clinic will be held on Tuesday, July 24 and then repeated on Wednesday, July 25, 2007. The topics include cover crop selection and management, no—till planter adjustments and attachments for use in cover crops, an overview of biomass crops for alternative energy use, nitrogen management issues, and pest management topics. As always, various credits will be offered.

Registration forms will be mailed and posted on our CMEG website (http://cmeg.psu.edu/) as time gets closer, so you can register and get additional information on each of the topics.

For additional information or comments about the Diagnostic Clinic contact Dwight Lingenfelter at (814) 865-2242 or by email, DwightL@psu.edu. August 14–16 – Ag Progress Days

Contributors: Dept. Crop & Soil Sciences: Bill Curran, Marvin Hall, Doug Beegle, Dwight Lingenfelter, Paul Knight. Extension Educators: Mena Hautau (Berks), Kevin Fry (Armstrong), Andrew Frankenfield (Montgomery), Mark Madden (Bradford), Tom Murphy (Lycoming), Grant Troup (Lebanon), Del Voight (Lebanon), Jeff Graybill (Lancaster), Joel Hunter (Crawford)

Editor:Joel Hunter

Upcoming Events

Real time pest and heat unit activity: http://psu.zedxinc.com/cgi-bin/site.cgi?location=2&user=psu#

Calendar of Events: http://www.events.psu.edu/cgi-bin/cal/webevent.cgi?cmd=opencal&cal=cal209&

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