CMEG Crop Management Extension Group

Field Crop News

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

March 11, 2008    Vol. 08:03

IN THIS ISSUE:

Weather Outlook — Paul Knight, Pennsylvania State Climatologist

The very wet weather pattern will abate at least for the next week or so. Temperatures will average near normal with milder conditions for the later part of the work week, then a push of polar air during the weekend and the start of next week and another more significant warm—up at the middle of next week. There are at least two more opportunities for snowfall in the state. A storm passing near or south of Pennsylvania later Saturday or early Sunday may bring some snow and a disturbance expected to develop in the Gulf States may threaten the region with snow next Thursday or Friday.

Overall, the winter has closely followed a typical strong La Nina pattern with above average temperatures and precipitation during February. The usual spring during a La Nina pattern would bring cooler than average temperatures, particularly from later April into May. Rainfall tends to be split with dry months alternating with wetter months. June is likely to be the wettest month of the summer.

Spring Weed Control in Alfalfa — Bill Curran and Dwight Lingenfelter, PSU Weed Science

As alfalfa comes to life this spring, there is opportunity and often time the need for weed control. Here are a few guidelines about available products:

Gramoxone Inteon 2 (paraquat) — May be applied at 2 to 3 pt/A to established “dormant” stands before 2 inches of spring regrowth. The weeds must be actively growing at the time of application. Gramoxone is also labeled at 1 to 2 pt/A for dormant application on new fall seeded stands. Gramoxone will desiccate any green tissue including actively growing alfalfa. Be especially cautious with new fall seedings. Gramoxone is effective on low to moderate infestations of winter annuals including chickweed, henbit, deadnettle, and mustard species. If winter annual weed infestations are severe, consider one of the soil active alternatives. Do not use on mixed stands.

Poast Plus 1E (sethoxydim) — Poast Plus controls annual grasses and suppresses perennial grasses in seedling and established alfalfa. Apply Poast Plus at 1.5 to 2.5 pt/A to actively growing grassy weeds. Poast Plus should be applied to small grasses and performance improves with warmer temperatures. Do not use on mixed stands.

Pursuit 70DG (imazethapyr) — Pursuit may be used for weed control in seedling (2 trifoliates or larger) or established alfalfa. Apply Pursuit at 1.08 to 2.16 oz/A plus adjuvants to actively growing weeds 1 to 3 inches in height. Pursuit performance improves with warmer temperatures. If spraying during extended cold periods, expect weeds to respond slower or the herbicide can have reduced activity. Pursuit is effective on many winter annual broadleaves including small chickweed. Pursuit may be used on established alfalfa—grass mixtures.

Raptor 1AS (imazamox) — Raptor may be used for weed control in seedling or established alfalfa. Apply Raptor at 4 to 6 fl oz/A plus adjuvants to small, actively growing weeds and to established alfalfa in the fall or in the spring. Any application should be made before significant alfalfa growth or regrowth (3 inches) to allow Raptor to reach the target weeds. Like Pursuit, Raptor performance is influenced by temperature. Therefore, try to apply the herbicide on warmer days and when weeds are actively growing. Raptor has a similar spectrum of winter annual weed control as Pursuit. Do not use on mixed stands.

Select 2EC (clethodim) — Apply Select at 6 to 8 fl oz to actively growing grasses that are less than 6 inches tall. Rates up to 16 fl oz may be used to control larger grasses, annual bluegrass or perennials such as quackgrass. Include a crop oil concentrate in the spray mixture. May be tank—mixed with Pursuit, Buctril, or 2,4–DB for broadleaf weed control. Do not use on mixed stands.

Sinbar 80W (terbacil) — May be applied to established alfalfa at up to 1.5 lb/A or to a new fall seeding at 0.33 to 0.5 lb/A. The reduced rate seedling year application is specifically aimed at chickweed. Sinbar is effective on a number of annual broadleaves and some grasses at the higher rates. Apply to ‘dormant’ alfalfa before 2 inches of spring regrowth. Do not use on mixed stands.

Sencor 75DF (metribuzin) — May be used on established alfalfa. Apply 0.5 to 1 lb/A before spring regrowth. Impregnation on dry fertilizer can improve crop safety and allow for slightly later applications (up to 3 inches spring regrowth). Sencor controls winter annual broadleaves and grasses (higher rates for grass control). May be used on mixed alfalfa—grass stands.

Velpar 2L (hexazinone) — Apply Velpar to established alfalfa at 2 to 6 pt/A during the dormant period before 2 inches of spring regrowth. Velpar is effective on annual broadleaves and grasses. Velpar is the most effective dormant season treatment for suppression of dandelion and dock species (higher rates for grasses and perennial suppression). Do not use on mixed stands.

Your best bet when controlling...
•Chickweed - Gramoxone Inteon, Pursuit, Raptor, Sencor, Velpar
•Annual bluegrass - Gramoxone Inteon
•Henbit/deadnettle - Gramoxone Inteon, Sencor, Velpar
•Yellow rocket - Pursuit, Raptor, Sencor, Velpar
•Dandelion - Velpar (suppression) or Pursuit (early spring is better)
•Curly dock (suppression) - Pursuit or Raptor (early spring is better)

Gully Erosion, Sjoerd Duiker – PSU Soil Management Specialistg

Last week was another one of those late winter events that may have caught us off guard. Rainfall recorded between March 1–10 varied from 1.66 to 4.57 inches in Pennsylvania (table 1), causing significant gully erosion. Infiltration was often minimal because subsoils were still frozen. Because the topsoil had already thawed, it easily washed away in places where runoff concentrated. Soil erosion was most severe in tilled fields, but no—till fields were not spared, either.

Table 1. Rainfall between March 1–10, 2008
Location Rainfall (")
Data from NOAA
Allentown 3.24
Poconos 4.57
Philadelphia 2.63
Reading 2.49
Erie 3.02
Pittsburgh 1.66
Williamsport 3.67
Harrisburg 3.43

Differences between the quality of no-tillage show up when we have catastrophic events like we had last week. If crop residue is customarily removed the aggregate stability of the soil is low, and soil is more easily washed away. Lack of soil cover also leads to high velocity of runoff, leading to increased rill and gully erosion. It made a difference whether cover crops were large and vigorous or tiny and feeble. A 3" tall, thick rye cover crop does a lot more good than a 0.5" tall, sparse rye cover.

What to do in the short term about the gullies that are in the field right now? It is necessary to fill the gullies back in with a tillage tool like a disk and plant them as soon as possible to a living cover. A good choice for this spring would be oats. Use no-tillage later or summer rainfall may cause new gullies to form later this year. Eventually, one may consider planting a grass waterway or a grass buffer strip in places where runoff concentrates. Grass waterways may be needed in fields with tillage and also no-till fields (although fewer will be needed in the latter case). If gullies formed in places where seeps come out on hillsides, it may be necessary to put in sub-surface drainage to address this problem. (Just in case you wonder: if the fields have been in crop production there are no regulations prohibiting you from installing sub-surface drainage.) Consult your local NRCS or Conservation District office to address gully erosion problems — they will be happy to assist you to address this pressing problem.

National Ag Day — March 20, 2008 — Paul H. Craig, Dauphin County Extension

Each year, on the first day of spring, United State’s Agriculture is recognized for its contribution to our society. Here are some interesting facts to share with your clientele, peers and families. The world population is at 6.2 billion today and is expected to increase by 20% to 7.5 billion by 2020. Today one American farmer supports more than 144 people, an increase from a ratio of 1:25 people in the 1960’s. One fourth of the world’s beef and nearly one—fifth of the world’s grain, milk and eggs are produced in the U.S. Clearly as the world’s population soars, there is an even greater demand for food and fiber produced in the United States.

Through research and changes in production practices, today’s agriculture provides Americans with the widest variety of foods, ever. Research and technology are now in the marketplace with tastier fruits and vegetables. Global Positioning Systems assist producers to map fields and is incorporated into site specific applications of fertilizers and crop protection products. With modern production methods, one acre of land can produce 42,000 lbs. of strawberries; 11,000 heads of lettuce; 25,000 lbs. of potatoes; and 8,900 lbs. of sweet corn.

Farm equipment has evolved dramatically from the team of horses used in the early 1900’s. In the 1930’s, before machines, a farmer could harvest about 100 bushels of corn in a nine hour day. Today combines can harvest 900 bushels of corn per hour or 100 bushels in less than seven minutes.

Do you know that two out of every five bushels of corn in the world originates in the U.S.? In 2001, 45% of the world’s soybeans were grown in the US and 13% of the world’s wheat. Forty—one percent of U.S. total land area is farmland or ranchland. In 1900 the average farm size was 147 acres, compared to 441 acres today. As a result of the abundance of American Agriculture, American consumers spend the lowest percentage of their annual income on food — just 9.3 percent. At the same time farmers and ranchers are maintaining and improving soil and natural resources to pass on to future generations. It is estimated that agricultural lands provide habitat for 75% of the nation’s wildlife.

Today, more than three million men and women farm or ranch in the United States. Individuals, family partnerships or family corporations operate almost 99% of U.S. farms. More than 22 million people are employed in farm or farm-related jobs including production, inputs, processing, marketing, retail and wholesale sales.

The American consumer is the beneficiary of these advances in Agriculture. Everyone who works in the food and fiber production system should be proud of their contributions. Share that pride on National Agriculture Day on March 20, 2008.

References for this article were found at the following website: http://www.agday.org/

Help for Identifying Common Pennsylvania Grasses — Marvin Hall, PSU Forage Specialist

Identification of different grass species is a challenge for almost everyone. A recent addition to the Penn State Forages web site may eliminate some of that challenge. “Identifying Common Pennsylvania Grasses” (http://www.forages.psu.edu/topics/species_variety_trials/commonpagrasses/index.html) contains descriptions and identification pictures for 21 of Pennsylvania’s most common grasses.

Threat of Soil Compaction — Sjoerd Duiker, PSU Soil Management Specialist

With a long winter, lots of snow melt and spring rains, we are ready to cause some serious compaction. Keep the following in mind:

Subsoil compaction depends on axle load, not on contact pressure. This means that reducing soil contact pressure by using flotation tires or tracks will not reduce subsoil compaction, although it helps to reduce surface compaction and sinkage. If you travel on soil that is really too wet with axle loads of 10 tons or higher, you're likely causing subsoil compaction below 20 inches. Research has shown that this compaction is there to stay. Freeze—thaw and wetting—drying cycles will not remove this compaction, nor will biological forces such as earthworms, roots, or microbial activity. Subsoilers usually don’t go this deep, nor can they completely alleviate this subsoil compaction (and at considerable cost!). Research in experiments in seven European and North American countries showed a 5% yield decrease due to subsoil compaction that lasted longer than 10 years. Although you don’t travel on 100% of the field with high axle loads in one year, you will probably get there in three years, so a 5% yield decrease due to subsoil compaction is not unrealistic. The key to subsoil compaction avoidance is to reduce axle load. This can be done by reducing the load or increasing the number of axles.

Surface compaction is caused by high contact pressures. Road tires inflated to 100 psi and iron wheels cause very high contact pressures. However, if axle loads are low (say below 6 or 7 tons per axle), subsoil compaction may not be caused. Surface compaction can cause very high yield losses the year immediately following the act. Tillage does not completely alleviate surface compaction. In the same series of international compaction trials they found on average a 15% yield loss due to the combined effect of subsoil and surface compaction the first year after compaction. In some cases (especially clay soils) yield losses amounted to 50% in the first year. The soil was moldboard plowed, but this did not alleviate surface compaction completely. In no—till, of course, yield losses due to surface compaction can be a lot more dramatic. Surface compaction is alleviated eventually due to natural and human means, but typically causes yield depression for a 4–5 year period. Research from Kentucky has shown that in long—term no—till soils will recuperate from most surface compaction without tillage within one whole year. Using flotation tires or tracks helps reduce surface compaction.

The key to soil compaction avoidance is to stay out of the field when it is too wet. If the soil is drier than the ‘plastic limit’ the threat of compaction decreases dramatically. A rough guide to determining the plastic limit is to take some soil and try to make a ball out of it. If that is possible, the soil is too wet for either traffic or tillage. Don’t fool yourself by taking soil from the surface only.

So, You Want to Conduct Your Own On—Farm Research? Ron Hoover, PSU On—Farm Research Coordinator

With herbicide and other pesticide costs gradually moving higher, and fertilizer prices climbing even faster, many farmers are giving consideration to alternative production practices or to products that may be new to them to help control costs of production. Add into the farm management decision process a continuation of high future prices for commodities and there continues to be interest in squeezing a few more bushels from each acre. But, there are questions to be answered. Does the new product or practice have a fit on my farm, on my soils, under my management practices? Is spending more to grow the crop to produce that last 3 or 4 bushels per acre cost effective? Conducting some of your own on—farm research this year can help you know if you made a good decision for 2008 and help you decide if you should continue the new practice in the future.

The first nugget of advice I can give someone new to on—farm research is to seek assistance. Contact another who has experience in planning and conducting tests. That person might be myself, or your local county extension educator. My contact info is located below. I can’t cover all the issues in this article that should be taken into consideration when undertaking a project. However, a few minutes of discussion with an advisor, even if simply over the phone, can provide valuable guidance for avoiding problems and helping to ensure you have a plan that allows you to collect quality information.

Try to keep the project simple, especially if you are new to on—farm research. This is especially true with respect to the number of treatments (products or practices) being compared. A comparison of two or three treatments is plenty with which to start. That doesn’t imply that you should have only 2 or 3 plots. To have confidence that one treatment may be better than another, we need to conduct multiple comparisons of the treatments. Multiple comparisons are known as replications. It is best to have the plots of all treatments that are assigned to replicate in close proximity to one another. Why? We need to work with the assumption that the productive potential of the 2 or 3 plots in a replication is very similar. If not, an “unfair advantage” is already given to one or another treatment, and any difference you record at harvest may be due to this difference in productive potential and not due to the treatments being evaluated. For most agronomic field tests, I suggest a minimum of 4 to 6 replicates.

Replicated data are able to be subjected to statistical analyses to help determine how likely the differences you recorded (averaged across replications) are due to the performance (yield) potential associated with the treatments and not simply due to random variation that is found in all our fields. Having access to computer software capable of performing statistical analyses is another reason to team up with an advisor. Another good friend to have during this process is your local seed dealer who has access to a weigh wagon, especially if you don’t have a yield monitor on your combine or it hasn’t been calibrated recently. Lack of adequate (or any) replication in their studies are the biggest problem I encounter with farmer—conducted projects. Without replication, farmers run a great risk of drawing erroneous conclusions. They might reject one product or practice and adopt the other, even though there was no real difference between them. Even worse, the “loser” in the trial might have really been the “winner” if the trial was conducted fairly. How so? Just due to chance, the “loser” was placed in the part of the field that:

  1. only received a spring manure application whereas the winner received fall and spring manure.
  2. was located on more shaley soil during a dry year.
  3. was on the part of the field that didn’t have the heavy rye cover crop 2 years ago.
  4. was on the side of the field where the fertilizer spreader ran out and the hired man forgot to finish that part of the field when the next load of fertilizer arrived.
  5. had been tilled where other parts of the field have been long—term no—till.
  6. …add your unfair advantage here…

Below is a typical plot plan.

Typical plot plan

Here is a short checklist of issues that should be considered while you plan your on-farm project.

  1. Identify a resource person or advisor.
  2. Choose the treatments you would like to compare (I suggest 2 or 3 at most).
  3. Identify what data are necessary to complete the evaluation (yield, plant counts, etc.)
  4. Plan the experiment: Have adequate replication, then have random assignment of treatments within each replication (see above).
  5. Layout the experiment: size the plots to fit your equipment →can each plot be 12 rows wide and the length of the field to allow a round trip with the combine when collecting harvest data?
  6. Develop a plot plan, keep good records.
  7. Initiate the test and begin collecting data.
  8. Share results with advisor, run statistical analyses.
  9. Can you draw valid conclusions??

Ron Hoover: (814) 865–6672 or rjh7@psu.edu

Upcoming Events

Need pesticide credits???
Penn State Pesticide Education Program will be “broadcasting” a 2+2 Pesticide Recertification Meeting via Adobe Connect Pro (Breeze) to counties throughout the state on Wednesday March 19th from 7:00 –9:00 pm.

A 2 + 2 meeting means there will be recertification training equivalent to 2 core credits and 2 category credits. The primary audience is private applicators. A private applicator permit is on a three—year cycle and credits must be accumulated by March 31 of the third year. This meeting will help those struggling to obtain credits before the deadline and was requested by members of the Pesticide Education Program’s Advisory Committee.

Unfortunately not all county extension offices are able to participate on this date. To find out if your county extension office is participating, give them a call.

Agenda
7:00 – 8:00 pm — Core Presentations — Eric Lorenz, Penn State Pesticide Education Program

8:00 – 9:00 pm — Category Presentations — Dwight Lingenfelter, Penn State Crop and Soil Sciences

Penn State Agronomic Field Diagnostic Clinic
July 22 and 23, PSU Agronomy Farm, Rock Springs, PA
(More details will follow in the upcoming weeks as plans are finalized.)
Contact: Dwight Lingenfelter (814–865–2242 or DXL18@psu.edu )

Next scheduled publication date: March 25, 2008.

Contributors: Department of Crop and Soil Sciences: Sjoerd Duiker, Marvin Hall, Ron Hoover, and Dwight Lingenfelter. County Extension Educators: Paul Craig (Dauphin), Andrew Frankenfield (Montgomery), Kevin Fry (Armstrong), Jeff Graybill (Lancaster), Mena Hautau (Berks), Mark Madden (Sullivan), Dwane Miller (Schuylkill), John Rowehl (York), and Del Voight (Lebanon).

Editor:Dwane Miller, Schuylkill County Cooperative Extension

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&

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.