CMEG Crop Management Extension Group

Field Crop News

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

June 6, 2006    Vol. 06:07

IN THIS ISSUE:

Soybean Rust Update — Dr. Erick De Wolf, Plant Pathology

Monitoring for soybean rust has intensified throughout most of the soybean producing states during recent weeks. This monitoring includes evaluation of soybean sentinel plots, commercial soybean fields and kudzu (another host of this fungus). As you may recall soybean rust appeared to have survived the winter in the deep south and was being reported in multiple locations in FL, GA and AL. However, our colleagues in these states report that hot and dry weather appears to have limited the development of the disease on kudzu and we have no reports of rust on soybean in 2006 to date.

The low levels of disease are good news for soybean farms throughout the country. Every week that passes with out significant increases of disease reduce the chance that soybean rust will cause damage to the U.S. soybean crop. At this time it appears the risk of soybean rust in Pennsylvania is very low. Soybean farmers in the state should continue normal production practices, but should also keep an eye on the status of soybean rust in the deep south. If the disease starts to increase in the gulf coast states the potential for rust may increase.

Pennsylvania will have 10 soybean sentinel plots this year. These plots are located in Montgomery, Lehigh, Lancaster, Franklin, Cumberland, Lycoming, Bedford, Centre, Indiana, and Mercer counties. Sampling of the PA sentinel plots began this past week and will continue until the crop matures. The Pennsylvania Department of Agriculture has also begun to monitor kudzu in the state for symptoms of rust, and to date they have not reported any rust.

Monitoring Wheat for Symptoms of Wheat Head Scab — Dr. Erick De Wolf, Plant Pathology

Wheat in most parts of Pennsylvania is now moving through the grain filling stages of growth. In the southeast, the crop is likely between the watery ripe and early milk stages of growth. This wheat was flowering during the frequent rains that occurred in mid— to late—May, and we received many questions about the potential for head scab this year. Our efforts to forecast the development of head scab suggested the risk of head scab was low during this period despite the availability of moisture during these critical growth stages. I feel like this is reasonable given the dry conditions in April and cool temperatures that dominated when the moisture was present; however, we will determine the correctness of these assumptions very soon.

Symptoms of head scab should become apparent during the next 10 to 14 days as the grain continues to fill. Symptoms of head scab include pale or tan discoloration of infected spikelets. These lesions may be limited to individual spikelets but may also encompass large sections of the wheat head. Infected heads may also have an orange or pink discoloration resulting from the spore production of the fungus. When checking for scab we suggest that you sample 10 locations in a field. At each of these locations, evaluate 20 heads for symptoms of the disease and record the number of heads with disease. The average number of heads diseased across all locations will give you a good estimate of the disease incidence in a given field. You can see images of the disease online at www.wheatscab.psu.edu and a fact sheet regarding head scab is available at this website or from the Penn State Small Grains Management website at http://smallgrains.psu.edu/diseases.cfm

Cover Crop Establishment in Standing Corn — Sjoerd Duiker and Dwight Lingenfelter

After last week's article about broadcasting a red clover cover crop in standing wheat, a few people asked if the same could be done in standing corn. In the olden days it was not uncommon to broadcast red clover (sometimes mixed with grass) in corn at the time of last in-row cultivation. Organic growers may still be using this practice. It would be nice to be able to broadcast red clover at the time of, say post-emergence herbicide application. The cover crop could be spun on either ahead or behind the sprayer, thus no extra pass would have to be made over the field.

The problem with this practice is the rotational restrictions after corn herbicides, see Table 2.2-19 in the Agronomy Guide (http://agguide.agronomy.psu.edu/PDF03/table2-2-19.pdf). Atrazine, for example, has a rotational restriction of 2 years for clover. So it is not possible to establish red clover in standing corn if atrazine has been used as a corn herbicide. Because most farmers use atrazine for weed control in corn this becomes an impediment to clover establishment in standing corn. There are few options to make in-crop establishment possible in corn. One could use a total-post program with Distinct (dicamba+diflufenzopyr with 1 month rotational restriction, a post-emergence broadleaf herbicide) and Option (foramsulfuron with 2 month restriction, a post-emergence grass herbicide). This program would still necessitate a 2 month waiting period after herbicide application before the clover can be spun on, which would be too late to be able to drive through the corn.

The best option for cover crop establishment in standing summer crops is with Roundup Ready corn or soybeans. To be completely safe, wait a day or two after glyphosate herbicide application before spinning on clover. Otherwise, the seed could potentially absorb a little glyphosate and this could kill the seedling. This herbicide program could not include a residual herbicide or 2,4-D because that would conflict again with rotational restrictions for these herbicides. Because most soybeans are already glyphosate resistant in our Commonwealth, there is a very good opportunity to establish a legume in standing soybeans this way. The nitrogen fixed by the clover (especially if the clover would be left unharvested) would benefit the following (non-leguminous) crop. The clover would also protect soil from erosion and improve soil quality.

Rose Rosette Disease Commonly Sighted on Mutiflora Rose — Bill Curran

Rose rosette disease (RRD) on multiflora rose (Rosa multiflora) is a common sight in some areas of central Pennsylvania. RRD is a suspected virus transmitted by an eriophyid mite that is a generally fatal to multiflora rose as well as some other rose species. We first identified this disease in the central region back in 2002 (www.weeds.psu.edu/News_ 2002/rrd02.html). RRD has been commonplace in W. Virginia and in parts of the Midwest and scattered throughout numerous other states including Pennsylvania. It has long existed in the southwestern part of PA and has been slowly moving North and eastward. Farmers and land managers plagued with multiflora rose have happily anticipated the arrival of RRD in the hope that it will reduce or even eliminate multiflora rose. Unfortunately, some ornamental roses are also susceptible, so rose enthusiasts are equally concerned about the spread of RRD.

Late May and early June are good times to see RRD symptoms on infected multiflora rose. The new leaves emerge with a brighter red to dark red mosaic pattern (www.weeds.psu.edu/News_2003/rrd03.html. The pattern follows the leaf veins or may appear as spots and blotches. A proliferation of shoots often produces a “witches broom”. Other symptoms include rapid stem elongation, breaking of axillary buds, which results in numerous red lateral shoots and thick bunchy clusters of wrinkled, reddish-green leaves, which are distorted and reduced in size. In general, the entire multiflora rose plant including the root system dies an average of 22 months after first becoming infected. On contemporary garden roses, the symptoms are usually less severe, but the disease also kills some cultivars. On some cultivars, the symptoms appear transient and the plants recover, while other plants weakened by RRD, die from other causes. Rose growers should watch for symptoms on cultivated roses and remove infected plant material immediately.

Although many farmers and other landowners may welcome RRD, don't expect it to solve the multiflora rose problem any time soon. My experience has been that for every plant that dies from the disease, two or three new ones become established over that period of time. Unless you've heard differently, I think multiflora rose is still alive and well in southwestern PA and W. Virginia.

Reminder: Tank Mix to Save Glyphosate's Usefulness — Dwight Lingenfelterr

As we move into the seasonal time frame of applying more post herbicides, this is just a reminder to always consider herbicide resistance management. With more and more acres of Roundup Ready crops being planted, properly managing herbicides, especially glyphosate, to prevent resistance is always a challenge. The first consideration is using the proper rate of glyphosate depending on the size of the weeds. In most cases, for 4-6 inch tall weeds use 0.75 lb acre of glyphosate. Be sure to increase glyphosate rates when required by larger weed sizes. Avoid thinking that glyphosate can control any weed, at anytime. Glyphosate does not provide equal control of all weed species. Another consideration is to tank mix with other herbicides which have different modes of action yet control a similar complement of weeds. Also tank mixing broadens the weed control spectrum and provides additional insurance for reducing resistance. In RR soybeans, tank mix with Pursuit, Scepter, Raptor, FirstRate, Classic, or Harmony GT. In RR corn, consider adding atrazine, Clarity, Distinct, or Resolve. Some of these herbicides provide some soil residual activity after the post application. And finally, timing of weed control is important because it contributes to better weed control and ultimately better yields. Our colleagues at Michigan State recommend the following:

Weeds should be controlled in:

15-inch row corn before weeds exceed 2-inches.
30-inch row corn before weeds exceed 4-inches.
7.5 and 15-inch row soybean before weeds exceed 4-inches.
30-inch row soybean before weeds exceed 6-inches.

These are just a few things to consider when using glyphosate to control weeds now while being concerned with its longevity as a useful product into the future.

Certified Crop Advisor Workshop Planned for July 24 — Jan Pruss

The American Society of Agronomy administers the Certified Crop Adviser Program (CCA), the largest certification program in agriculture with over 14,000 certified throughout the USA and Canada. This program was created for advisers/consultants who advise growers on agronomic practices and meet the standards of the program.

CCAs are recognized by the U.S. Department of Agriculture Natural Resources Conservation Service (USDA-NRCS) as eligible to register as Technical Service Providers (TSPs). They provide assistance to farmers in protecting resources through conservation planning in soil and water, nutrient, crop and pest management. CCAs are also recognized as Agricultural Experts by the USDA Risk Management Agency which administers the Federal crop insurance programs. The Pennsylvania Park-the-Plow project requires farmers to work with only CCAs in establishing their no-till programs.

In February 2006, nine individuals from Pennsylvania passed the International and State exams; three of the nine have been certified; they are Harry Farlow from Upper Dauphin Grain, Justin Dillon from the Plant Pathology Department at Penn State University and Terry Lutz from the SulBra Crop Management Association. The remaining six are in the process of fulfilling additional certification steps.

The next CCA exams will be administered in Harrisburg on August 4, 2006. The Pennsylvania and International exam fees are $100 and $125, respectively. The registration period is from May 1 to June 16. To register go to http://www.agronomy.org/cca/exams.html.

On July 24, Penn State faculty and staff from the departments of Crop & Soil Sciences and Plant Pathology will hold a one-day workshop at University Park to prepare individuals planning to take the August exams. The workshop will be held in Room 205 Agricultural Sciences and Industries Building. It will start at 8:30 a.m. and end at 5 p.m. There is no charge for attending the workshop. To register, call or e-mail Lisa Crytser (814-865-2543, lac8@psu.edu). The Pennsylvania Certified Crop Advisor Study Guide is also available to assist you in preparing for the exam. The guide is available from Amy Bradford (abradford@pennag.com) at PennAg Industries.

Everyone serving or planning to serve the crop production industry should take this opportunity to become certified.

Cereal Leaf Beetles — Mena Hautau

In various parts of the state, there have been outbreaks of cereal leaf beetle in oats, in some cases, severe. See the Penn State Agronomy Guide for recommendations of thresholds and insecticides, Table 2.5-8.

According to Herbert Ames, Virginia Tech, cereal leaf beetle eggs are normally parasitized in the Mid-Atlantic states. Timely planting dates help to suppress populations. To read more, go to http://www.ext.vt.edu/pubs/entomology/444-350/444-350.html

Agronomy—Industry Field Day

To: Crop Professionals and Innovative Producers
From: Dave Johnson
When: June 30, 2006
Time: 9:00 am - 3:45 pm
Where: Landisville Research Center, Auction Road, Near Manheim, PA
Cost: $10 (Advance registration required)

Objective: Penn State will host a joint agronomy-industry field day on June 30, 2006 at the Southeast Area Research and Extension Center. The field day will feature faculty and staff from Penn State’s Crop and Soil Sciences, Entomology, and Plant Pathology Departments discussing the latest developments and key topics in agronomic crop and soil management. In addition, representatives from industry will be on hand to discuss and showcase in the field their latest technologies. ***Pesticide and CCA credits will be available***

Speakers

Penn State Speakers: Doug Beegle, Bill Curran, Jeff Graybill, Marvin Hall, Dwight Lingenfelter, Greg Roth, John Rowehl.

Industry Participants

AMVAC, BASF, Bayer CropScience, Dow AgroSciences, Dupont, Monsanto, and Syngenta.

Agenda

Tour A

Tour B

Credit Card Registrations can be mailed, faxed to Lisa at (814-863-7043) or telephoned to Lisa at (814-865-2543). Additional information can be found on the CMEG website or by contacting Lisa lac8@psu.edu

Field Day Announcement — Using Cover Crops for Ecological Weed Management

Three diverse field days will be offered this summer focused on managing cover crops and weeds. We will emphasize ecologically-based weed management aimed at prevention and maximizing beneficial processes within the farming system. Programs will be offered at the Penn State Agronomy Farm near State College on June 13, 2006, Village Acres organic farm in Juniata County on June 28, and at Cedar Meadow Farm in Lancaster County on July 14. These programs are part of the Pennsylvania Association for Sustainable Agriculture (PASA) 2006 Farm-Based Education Series and involve Penn State, PASA, and other organizations. Pest Management CEU's will be offered for those that are Certified Crop Consultants. For more information, contact Heather House at PASA at 814-349-9856, ext. 7 or register online at www.pasafarming.org

2006 Penn State Agronomic Field Diagnostic Clinic — July 18 and 20

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 18 and then repeated on Thursday, July 20, 2006. The topics include:

Various credits will be offered.

Registration forms are being mailed, so look for yours soon, to register and to get additional information on each of the topics. The cost of this year's Clinic is $45/person ($65 after July 12); credit card payments are being accepted this year. If you do not receive a registration form within a couple of weeks and would like to attend, contact Lisa Crytser at (814) 865-2543 or email- LAC8@psu.edu. Or visit our website at http://cropsoil.psu.edu/extension/clinic.htm for more information.

For additional information or comments about the Diagnostic Clinic contact Dwight Lingenfelter at (814) 865-2242 or by email, DwightL@psu.edu.

Contributors: State Specialists: Erick DeWolf, Bill Curran, Marvin Hall Dwight Lingenfelter, Sjoerd Duiker, Greg Roth, Department of Crop and Soil Sciences. Extension Educators: Andrew Frankenfield (Montgomery), Don Fretts (Fayette), John Rowehl (York), Susan Alexander (Jefferson), Duane Miller (Schuylkill), Andrew Frankenfield (Montgomery), Mena Hautau (Berks), Joel Hunter (Crawford), Mark Madden (Sullivan).

Editor: Tom Murphy

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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