CMEG Crop Management Extension Group

Field Crop News

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

August 4, 2009    Vol. 09:22

IN THIS ISSUE:

Weather Outlook — Paul Knight, Pennsylvania State Climatologist

A heat wave is coming for early next week with temperatures in the 90’s in most places on Sunday and Monday and several spots in southeastern Pennsylvania may rise above 100°F. Before the hot weather arrives, there will be several rounds of thunderstorms. A cool front crossing the state on Wednesday will trigger scattered thunderstorms — mainly in the southern and eastern half of the Commonwealth. It will turn noticeably cooler and drier by Thursday. The progression of hot air toward the region will produce clusters of thunderstorms, initially in the western half Friday night or Saturday morning, then another cluster on Saturday afternoon and evening farther east and perhaps a final cluster in northeast sections on Sunday morning. On balance, Saturday will be a hazy, dull day with a marked increase in humidity. Sunday and Monday will be mainly sunny and quite hot and very humid. A smattering of thunderstorms is possible late Monday in the mountains. Drier and a somewhat cooler air (though still warm) will arrive on Tuesday. There is a split in the outlook for the latter half of next week, but odds favor a couple of wet days (most likely Fri-Sat).

The very slow start to the hurricane season is not surprising. There should be an active period from August 20-September 12 when a couple of storms strike the U.S. coastline (probably western Gulf and Southeast). A very cool spell is likely during mid-September, with perhaps an unusually early end to the growing season in the northern counties. However, the latest indications point to a warmer than average September and October. The expected development of a moderate El Nino in the Pacific portend a wetter winter (and probably snowier) in the state.

Barley: A Crop with Many Possibilities — Greg Roth, Penn State Grain Crop Specialist

We have concluded another year of winter barley trials and have recently posted the preliminary data on our Web site. One of the interesting things about our barley trial is the diversity of entries. There are differences in height, beards, maturity, hulls and test weight. This year we tested several experimental lines, which included both hulless and some later European germplasm. We were able to collect a bit of more detailed data at the Rock Springs location this year, including spring vigor and heading dates. There were some differences in spring vigor but they don’t always translate into differences in yield. Heading dates varied, with early lines like Barsoy and Eve and many of the experimental Seedway lines being very late. It is uncertain whether any of these late lines could be commercialized because of their maturity but is also interesting how well some of these lines yielded. We also expressed the yields of all lines, including the hulless on a 48 pound test weight to avoid confusion. Yields of the conventional hulled lines averaged across both locations ranged from 103 to 114 bu/acre and the hulless lines averaged near 90 bu/acre. These yields are similar to some I have heard from barley producers this year.

Barley is a crop that seems to be underutilized in Pennsylvania. It has real potential on shallower soils where corn is often not profitable due to drought stress. It also provides some cash flow in the summer. Here are some ideas of potential ways some producers are finding to include barley in their rotations:

Interest is developing in hulless barley as a corn substitute in poultry feed in some circles. One strategy is to grow an early hulless line, like Eve, then follow with double crop soybeans.

Barley is an excellent substitute for corn in beef or dairy rations. Cover crop corn silage fields with barley, then harvest for grain and utilize the barley next summer instead of buying expensive stored corn.

Take the dairy strategy one step further and harvest the barley for high moisture grain a week earlier and then consider double cropping with soybeans where you might not otherwise. Think about the potential of this early cut straw as a feed rather than a bedding material.

In long season areas, intensify your rotation with a short season corn for grain, no-till barley in early October and follow with double crop soybeans in June. In a year like this, soybeans following barley will yield nearly as high as full season soybeans.

Overseed your barley with red clover in the winter, harvest the grain and let the clover grow up in the stubble and the follow with corn the following year. (This also works well for organic farms where organic barley is $6/bushel and the N from the clover will meet the needs of the corn crop).

If one of these strategies has merit for fields you are working with, now is the time to review barley variety options and make plans for barley planting in September or October.

Billbugs and Diseases in Orchardgrass — Marvin Hall, Penn State Forage Specialist

Last week I participated in a workshop that addressed early thinning of orchardgrass stands in the mid-Atlantic States. Two areas of discussion were diseases and insects that infect orchardgrass. I’ve summarized the material from these presentations to share with the readers of the Field Crop News.

Billbugs: by Tim Mize. Extension Educator from VPI.

Fig. 5, 6 and 7 larvae in crown and roots

Billbug Control: Controlling the adults offers the best option when billbugs become habitual problems. Two behavior characteristics strengthen this choice. Since the adult female rarely flies they crawl into uninfested fields each spring. Secondly they have only one generation a year. Thus an April to mid-May application of an insecticide will kill the adult females before they lay eggs and reinfestations may not reoccur for 2-3 years after treatment.

Diseases: by Erik L. Stromberg, Extension Plant Pathologist. VPI.

Fig. 8 Brown stripe on orchardgrass
Brown Stripe (see Fig. 8)
Fig. 9 Leaf blotch on orchardgrass
Leaf blotch (see Fig. 9)
Fig. 10 Powdery mildew on orchardgrass
Powdery mildew (see Fig. 10)
Fig. 11 Summer blight on orchardgrass
Summer blight (see Fig. 11)
Fig. 12 Barley yellow dwarf virus on orchardgrass
Barley yellow dwarf virus (see Fig. 12)

Disease Control: The best management for these foliar diseases is to remove the infected tissue and disease inoculants and hope for dry and warm weather during the orchardgrass regowth.

Assessing Nitrogen Losses in Corn — Jonathan Rotz, Franklin County and Doug Beegle, Penn State Soil Specialist

brown mid-vein on corn

Corn silage harvest is drawing near and as harvesters pull into fields across the state some may question the health of their corn fields. One note that will be made is the number of brown leaves on the corn, is this a problem?

With a wet spring and summer for many producers, there is a very real possibility that some nitrogen (N) was lost to denitrification. Through denitrification soil microbes remove oxygen from nitrate molecules under saturated conditions. Once this oxygen is removed the N is lost from our fields as gaseous N. This can be an exceptional issue in fields that have their entire N applied early in the spring prior to planting in the form of either manure or commercial fertilizers. Once this N is gone, unless additional N is added, a real possibility is that the corn crop may run out of N and thus will not reach its maximum yield potential. So do those lower brown leaves mean the crop lost some yield? Not necessarily.

Research done in central and southeastern Pa. has shown that when 4–5 green leaves are present at and below the corn ear leaf there is no N deficiency over 95% of the time (Fox et al. 2001). This research went on to state that of those plants with less than 4 green leaves only 50% were N deficient. Therefore, at harvest time brown leaves can be present on a perfectly healthy plant. Additionally, a plant that is green the whole way to the ground may have had N over applied, an expensive mistake that should be accounted for next year.

brown leaves on corn

With all these possibilities a few questions are bound to surface. Did your N management allow for adequate N, N deficiencies, or over application of N? How should your management change next year according to these? For example if you over applied nitrogen, retain some of it for next year’s crop with a grass cover crop. If you have been reading Field Crop News regularly you have heard of various tests for N levels such as the chlorophyll meter and the Pre-sidedress Nitrate Test. These tests help us forecast our crop needs under normal conditions. However at the end of the year another test can be utilized as a review of how well management reflected crop needs, this test is called the late season stalk nitrate test. This test is very good at identifying sufficient, deficient, or excess levels of nitrate in the stalk prior to silage or grain harvest. Once this is known, this season’s management can be scrutinized for its strengths and weaknesses so next year we can come closer to maximizing yield while minimizing N cost and environmental impact. For more on how to utilize the stalk nitrate test watch an instructional video or call or go to your local extension office and get more information on this test. A new factsheet on the Late Season Stalk Nitrate Test is also available on the CMEG Web site.

One last point, if corn has been N deficient it will not only lead to lesser yields it will also affect the quality of the silage. Low N levels will lead to lower protein levels and higher fiber levels in the silage. If this is a problem you are facing, one possible solution may be to harvest alfalfa haylage a little younger than normal to try to boost its protein level. This may help make up for the shortfall in the corn silage. With this being said, also remember that harvesting alfalfa in short intervals can have an effect on the longevity of your stand. Additionally you will sacrifice yield to increase the quality of your alfalfa haylage, however protein is rarely cheap to supplement into your ration. As always feel free to contact your local extension agent for further information.

Summer Seedings of Alfalfa — Paul Craig, Dauphin County

The abundance (over abundance actually in some areas) of soil moisture is creating a perfect opportunity for a summer seeding of alfalfa across PA. Many forage producers actually favor summer seedings over the “traditional” spring seedings because there is usually less weed and insect pressure. And soil conditions and time challenges can be more favorable this time of year compared to early spring.

Frequently referred to as a fall seeding, most successful seedings of alfalfa at this time are actually mid to late summer seedings, usually early to mid August. Seeding into small grain stubble is the most common establishment practice however some late summer seedings are actually reseedings into unsuccessful spring establishments.

Ideally summer seedings should have 8 to 10 weeks of growth prior to the date of the first killing frost. Seeding too late does not allow the seedling plants to develop adequate root carbohydrates for winter survival. Also later seedings can result in small root systems that may tend to increase the risk of winter injury from heaving before next spring.

Soil moisture conditions at establishment are critical. There is no sense making a seeding if adequate moisture is not available to ensure germination and development of small roots. Base your establishment decisions on existing soil moisture conditions and short term weather forecasts. Because of warmer soil temperatures with adequate soil moisture levels, seeds will germinate and develop much faster than spring seedings.

Getting ready for a summer seeding

Hopefully since small grain harvest soil sampling has been completed. Correcting soil pH levels and providing adequate levels of phosphorous and potassium are best made prior to establishment. Control of existing weeds prior to establishment is also important. If perennial weeds such as quack grass, hemp dogbane, pokeweed or burdock are present, be certain to apply adequate amount of herbicides to get optimum control.

No till establishment in summer seedings is preferred, if proper seeding equipment is available, due to the advantage of retaining soil moisture. If tillage will be used to prepare a seedbed be certain to consider the “fluffiness” of the seedbed. A loose seedbed in summer seedings can significantly reduce germination and establishment. In most tilled ground, the use of a cultipacker before and after seeding is beneficial. Consider what affect tillage will have on existing soil moisture levels prior to seeding. Seed at recommended seeding rates and at a depth of ¼ to 3/8 inch.

Post establishment weed control challenges will need to be monitored. Summer annual weeds will not become well established. However, winter annual weeds including chickweed, purple deadnettle and many others will germinate in September and October and can present significant problems if not controlled. In small grain stubble fields volunteer small grains can present another weed control issue. There are many options for weed control available. Treat this year, when weeds are small. Controls next spring will be less affective.

Do not harvest late summer stands this fall. By not harvesting root reserves will be maximized resulting in improved winter survival and rapid plant development next spring. Next spring; manage the stand as you would your other established stands.

Soybean aphid numbers increasing — John Tooker, Penn State Entomology Specialist

Recent warm temperatures have been perfect for soybean aphid development and, as a result, populations have grown toward the 250-aphids-per-plant economic threshold. We are aware of several fields in central PA that easily exceed threshold and we have even found plants with close to 1000 aphids. This is not an insect that can be diagnosed from the truck of a vehicle, so get out and walk those fields! Populations in our sentinel plot system do not reflect these large numbers, but fields in Maryland and Delaware are approaching or exceed threshold (National Soybean ipmPIPE Web site for details). All growers need to be aware of the increased risk for economically damaging aphid populations. After soybeans reach R6 stage, soybean aphids no longer appear to influence yield and need not be managed.

Nitrogen Management Field Day

Thursday, August 13th, 9:00 – 11:30 AM

Penn State SE Research & Extension Center
1446 Auction Road, Manheim, PA

One of the most challenging issues of 2009 was effectively managing fertility, particularly NITROGEN. Nitrogen deficiency appears to be more widespread this year and can easily be spotted in corn fields where the lower leaves have begun turning yellow and a general pale and unevenness exists.

Farmers, Lancaster Farms Participants, and Ag Professionals are invited to view some of Penn State’s research on nitrogen response, hear from some of the experts on using nitrogen measurement tools, and join a discussion on managing this essential and expensive nutrient.

Topics and speakers include:

No cost to attend. Reservations are not required but appreciated at Lancaster Ext. 717-394-6851

Meeting qualifies for 1.5 PA Nutrient Management Credits

Ag Progress Days

The Penn State Crop Management Extension Group (CMEG) hopes to visit with you at Ag Progress Days beginning on Tuesday, August 18th and running through Thursday, August 20th. See the APD Web site for daily times and specific attractions. Sponsored by Penn State’s College of Agricultural Sciences, the event is held at the Russell E. Larson Agricultural Research Center at Rock Springs about nine miles southwest of State College on Pa. Route 45.

Ag Progress Days is the largest outdoor agricultural exposition in the state attracting more than 400 commercial exhibitors displaying their latest goods and services. Interactive educational exhibits, guided tours and workshops will show how agricultural researchers and educators are addressing important issues, safeguarding and improving our food supply and the environment, and helping to enhance the efficiency and profitability of agriculture and related industries.

The crops, soils, and conservation exhibits will again be located together at the traditional location for the crops and soils exhibits at the end of 5th Street. We will be hosting several Penn State Department exhibits, exhibits from allied organizations such as the Pennsylvania Corn Growers Association, the Pennsylvania Forage and Grassland Council, and the Pennsylvania No-till Alliance. In addition, the many agencies and organizations that support agriculture and natural resources conservation such as NRCS, USDA’s Pasture Systems and Watershed Management Research Unit, the Pennsylvania Department of Agriculture, the Pennsylvania Department of Environmental Protection, and the Pennsylvania Game Commission will have exhibits located here.

Specialists and county educators from CMEG will be on hand to field questions and discuss crop production issues. We’re interested in what you have to say so please make time to visit with us.

Admission and parking are free and there is plenty to do for the entire family, so join us for a day and celebrate the promise we all share for Pennsylvania agriculture!

Contributors: Extension Educators: Paul Craig (Dauphin), Kevin Fry (Armstrong), Mark Madden (Sullivan), Jeff Graybill (Lancaster), Susan Alexander (Jefferson), Mena Hautau (Berks), and Jonathan Rotz (Franklin). State Specialists: Ron Hoover, John Tooker, Sjoerd Duiker, Greg Roth, Doug Beegle and Marvin Hall.

Editor: Kevin Fry, Armstrong County

Upcoming Events

Real time pest and heat unit activity: http://agsci.psu.edu/news/spotlight/pa-pipe

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

If you have any questions or would like to suggest a topic, please contact your local Extension Educator.

Readers can subscribe electronically to this newsletter at the Field Crop News Web site.

If you have problems subscribing or wish to cancel your subscription, please contact Lisa Crytser by e-mail at lac8@psu.edu or by phone at 814-865-2543.

Information presented above and where trade names are used, they are supplied with the understanding that no discrimination is intended and no endorsement by Penn State Extension is implied.

This publication is available in alternative media upon request.

The Pennsylvania State University is committed to the policy that all persons shall have equal access to programs, facilities, admission, and employment without regard to personal characteristics not related to ability, performance, or qualifications as determined by University policy or by state or federal authorities. It is the policy of the University to maintain an academic and work environment free of discrimination, including harassment. The Pennsylvania State University prohibits discrimination and harassment against any person because of age, ancestry, color, disability or handicap, national origin, race, religious creed, sex, sexual orientation, or veteran status. Discrimination or harassment against faculty, staff, or students will not be tolerated at The Pennsylvania State University. Direct all inquiries regarding the nondiscrimination policy to the Affirmative Action Director, The Pennsylvania State University, 328 Boucke Building, University Park, PA 16802-5901, Tel 814-865-4700/V, 814-863-1150/TTY.