Field Crop News, Vol. 11:31, November 8, 2011
November 8, 2011 Vol. 11:31
IN THIS ISSUE:
- Weather Outlook
- How Late Can I Control Perennials in the Fall?
- Tidbits on Fall Control of Chickweed and Horseweed
- Fall Manure Applications to Forage Stands
- Price Expectations of Unsold Grain
- Nutrient Removed from Baling Corn Stover
- Upcoming Events
Weather Outlook — Paul Knight, Pennsylvania State Climatologist
The mild and tranquil weather pattern that has persisted the past few days over the state will come to an end late Wednesday evening. A cold front will pass across the western part of the state very early Thursday and towards mid-morning across the eastern part. Breezy conditions with scattered rain showers are likely during the day on Thursday in the east, with a chance of snow showers after sunset in northern and western parts of Pennsylvania. Snow showers will end in the north and west by midday Friday, with the remainder of the area experiencing partly to mostly sunny skies with gusty winds. Behind the front on Friday, temperatures will drop to between 5 and 10 degrees below normal. Over the weekend partly to mostly sunny skies with moderating temperatures are expected with another spell of much above temperatures likely for the first half of next week. Odds favor mild weather continuing until Thanksgiving week when somewhat colder air should reach the East Coast. While the winter is expected to be milder than average, a period of cold, wet (snowy) weather is favored during December or early January.
How Late Can I Control Perennials in the Fall? — W.S. Curran and D.D. Lingenfelter, Weed Science
I have been asked several times in the last couple of weeks whether we can still kill perennial weeds with herbicides this late in the fall as well as some cool season forages like alfalfa. Weeds like Johnsongrass, pokeweed, and other more tender herbaceous perennials have already entered dormancy; however there may still be opportunities for some of the cool season species.
Here in the central part of the state our night-time low temperatures have routinely been right around 30° F and perhaps as low as 26 or 27° F. Usually, fall can be an excellent time to target herbaceous plants for control, but we have moved beyond the optimum time for effective control. Research conducted in Nebraska back in the late 1990’s showed that applications following the first frost of the season (temperature drops below 32 F, but leaf tissue is not damaged) actually provided a significant increase in control with several perennials. This research reported a 17 to 39% and 45 to 58% increase in control of Canada thistle and dandelion respectively if dicamba (Banvel or Clarity) is applied after the temperature dropped below 29 F compared to 5 days before the first frost (Wilson and Michiels 2003). This would probably be similar for other effective herbicides as well, but this elevated control is dramatically reduced after a hard freeze that kills foliage of Canada thistle. With most plants it is possible to determine whether the foliage has been severely affected by frosts, thus scouting the field prior to application is important to ensure that active green foliage is still present. In general, if temperatures drop below 28 degrees at night for more than 4 hours then these plants may die and an herbicide application may not be effective. The study we have often quoted in an article like this is some work conducted by Nathan Hartwig back in 1970’s looking at the effect of glyphosate timing on quackgrass control. Dr. Hartwig applied a 1 lb/acre rate (1 qt of a 3 lb ae/gal formulation) in late September, early October, and November and rated the plots the next spring. The late September treatment provided greater than 90% control, the early October 80 to 90%, and the November treatment 50 to 60% control. Of course more mild weather or an Indian summer would likely improve the November results.
In general, fall foliar applied herbicide applications should be made when daytime air temperatures are at least in the 50’s and preferably higher. If warm temperatures (greater than 65 degrees) like we have today and tomorrow return for several days, the time is now. Applications when plants aren’t actively growing will limit herbicide uptake or movement, resulting in poor control the next year. Also, when applying systemic herbicides this late in the year, make sure to include adjuvant such as AMS and/or crop oil concentrate to insure adequate uptake of the herbicide.
Tidbits on Fall Control of Chickweed and Horseweed — Dwight Lingenfelter, Weed Science
With the recent stretch of nice fall weather, we continue to get questions about control of certain winter annual weeds, namely common chickweed and horseweed/marestail.
Horseweed has been a growing concern the past several years and although we have conducted research on this weed, Mark Loux and his colleagues at Ohio State have some helpful insight on this specific species. Instead of reinventing the wheel, here are a few highlights and references to his articles for further information.
- Keep cost of fall herbicide treatments in the range of $4–12/acre. Glyphosate + 2,4–D can be an initial low cost option to consider that provides control of a relatively broad spectrum of weeds.
- Products that contain chlorimuron (e.g., Canopy) tend to provide the most residual horseweed control into spring. (Keep in mind there are areas in Delaware, Maryland and in the Midwest that have ALS+glyphosate—resistant horseweed, so chlorimuron or other ALS herbicides would not provide control in these situations.)
- Fall only burndown/residual applications generally do not provide enough control of horseweed into next season. Two-pass burndown programs (fall followed by spring applications) are better at obtaining season-long horseweed control.
- If applying a fall burndown, make sure to select the correct product depending on what crop you intent to plant next spring. For example, don’t apply a Canopy product if you plan to plant corn.
(Photos of horseweed taken in early November. Curran, Penn State)
For more details on the above points, please review articles about horseweed management from Ohio State:
Fall Herbicide Treatments - Focus on Marestail Management
Do We Need a Systems Approach to Marestail Management?
What We Learned About Marestail in 2010
Common chickweed in another weed we have been hearing more about not only in small grains but in forage crops as well. In wheat, barley, and oats, unless it is ALS-resistant, Harmony Extra (or equivalent generic product) is one of the better options. (On as side note, if you have horseweed in small grains, Harmony Extra usually provides good control.) If you are one of the unfortunate who have an ALS-resistant chickweed population then programs that include Starane (fluroxypyr) appear to be providing the best control. We are currently conducting a couple studies on ALS-resistant chickweed in small grains, so we hope to have a better handle on this by next spring.
If chickweed is a problem in alfalfa, then some options include Pursuit, metribuzin, Chateau, and Gramoxone. Only Pursuit and metribuzin are labeled for use in alfalfa/grass mixtures. Also, as we get later in the year, products like Pursuit tend not to be as effective due to colder conditions that affect weed growth. If you are struggling with chickweed in grass hay or pasture, a combination of dicamba (Clarity, Banvel, others) plus 2,4–D will provide some suppression (70–80% control). This tank-mixture works better on chickweed in the fall compared to spring applications where it typically provides only about 50–60% control.
Fall Manure Applications to Forage Stands — Paul H. Craig, Dauphin County
With the wet conditions during September, the current spell of drying weather, the short forage supply due to the drought of 2011 and extremely high prices, many forage producers have taken a final harvest of grass and alfalfa forage crops. Maximizing your forage supply will be extremely important this year due to tight supplies and high prices for replacement forages. Be sure to use forage analysis on all your forages frequently this feedout period.
With the late season harvest these forage stands can provide an opportunity to empty manure pits and provide the crop with needed nutrients for next year. Alfalfa and forage grasses are heavy consumers of soil nutrients. Book values for nutrient removal by alfalfa are 50 # N, 15 # P2O5 and 50# K2O. Orchardgrass removes 50 # N, 17 # P2O5 and 62 # K2O and Timothy 38 # N, 14 # P2O5 and 62 # K2O per ton of dry matter. A typical 5 ton/acre/year alfalfa crop removes 250 # N, 75 # P2O5 and 250 # K2O and a 4 ton orchardgrass harvest removes 200 # N, 68 # P2O5 and 248 # K2O. Without close monitoring with soil test reports or fertilizer budgets, soil fertility levels can be dramatically lowered during the 4 to 6 year life span.
Fall applications of manure to forage stands can be used to meet the high demands of forage nutrients if some agronomic and environmental considerations are kept in mind. The challenges of manure applications to forages are related to soil and stand conditions. Fall manure applications are a great time to address P2O5 and K2O levels. They also save time in the spring, when soils also tend to be wetter. Fall manure applications also help root development before winter dormancy and help spring growth get started. Weed scientists report less weed stimulation from fall manure applications compared to spring applications.
Wheel traffic can cause surface and deep compaction when soil conditions are not fit. Over the lifespan of the stand this compaction can lead to reduced water infiltration and decreased surface and deep root development. Injury to the developing shoots and the crowns can also lead to reduced stands. Drag line manure applications can also injure shoots and crowns. Using flotation tires and smaller loads can reduce these effects but staying off poor soil conditions is important.
Environmentally, fall manure applications can lead to a greater risk of runoff. Applications made to forage stands will limit this risk compared to applications to corn silage fields. Another risk more common in wetter areas is infiltration into tile lines. Producers should be aware of field conditions when applying manure at any time of the year.
Liquid manures are preferable to bedded pack manures on forages. Smothering of the crop and the potential for picking up manure clumps next spring increase with bedded pack manures. A typical rate of 3000 gal/acre of liquid manure in the fall will be adequate. Priority for fall manure applications should be older grass stands first, followed by the oldest alfalfa stands and then younger stands last. Be sure to stay out of waterways and 100 feet away from streams.
Check your crop records and soil test reports to closely monitor soil nutrient levels. It is still possible to take advantage of this fall weather to address nutrient needs and distribute manure to targeted areas.
Price Expectations of Unsold Grain — John Berry, Lehigh County
From our latest USDA, NASS crops progress report we see some lingering effects of excessive fall moisture - extended harvest windows and delayed small grains development.
| Crop | Current Week Percent |
Last Year Percent |
5-Year Average Percent |
|---|---|---|---|
| Fall plowing | 61 | 72 | 77 |
| Corn, harvested | 57 | 76 | 67 |
| Barley, harvested | 92 | 98 | 98 |
| Barley, emerged | 60 | 92 | 92 |
| Wheat, planted | 74 | 88 | 92 |
| Wheat, emerged | 61 | 73 | 75 |
| Soybeans, harvested | 49 | 82 | 70 |
| Potatoes, harvested | 96 | 99 | 98 |
| Alfalfa, 4th cutting | 90 | 97 | 96 |
| Crop | Very Poor Percent |
Poor Percent |
Fair Percent |
Good Percent |
Excellent Percent |
|---|---|---|---|---|---|
| Wheat | 0 | 1 | 35 | 41 | 23 |
| Soybeans | 2 | 6 | 23 | 49 | 20 |
| Pasture | 7 | 15 | 37 | 30 | 11 |
I look to the current market for some indications of what to do about pricing any remaining 2011 bushels. This morning’s market tells me:
Local Cash
- Corn - 7.04
- Soybeans - 11.43
2011 CME
- DEC Corn - 6.55
- NOV Soybeans - 12.00
For my 2011 corn and beans that do not yet have a buyer - basis is “good” for both crops. This is one signal that tells me to go ahead and price/move the crop. Prices are relatively high for both crops. This is another signal that tells me to go ahead and price/move the crop. Neither crop offers significant carry - so setting a price and storing bushels for future delivery is not necessarily being suggested by today’s market conditions. The only remaining selling method to consider for 2011 production is to store bushels un-priced.
If I choose to store un-priced; Do we know what price we are waiting for?
Reviewing 20 years of market data we see that we can “reasonably” expect corn prices to gain $0.75/bushel over harvest levels and soybeans to gain $2.00/bushel. So, if I could have sold corn off the combine for $7.00, the most I should be expecting from my stored corn is $7.75 (or so). The most from my soybeans would be $13.40 (or so).
If we are storing un-priced 2011 grains - What price do we expect to get?
Nutrient Removed from Baling Corn Stover — John Rowehl, York County
Harvesting corn fodder removes nutrients that would otherwise be recycled back to the soil for subsequent crops as well as organic matter that is more difficult to put a price on but is still a consideration. Research currently underway at Penn State is looking at removing varying amounts of corn fodder and its effect on crop production. While more time will be needed to see the long term effects, measurements of fodder removal and nutrient content are being made. Some figures of nutrient costs from fodder removal using recent fertilizer costs were recently reported by Dr. Greg Roth at the Keystone Crops and Soils Conference. With 3 tons of corn stover removed, the combined value of phosphorus and potash was estimated to be just over $54 per acre.
As corn fodder weathers, potassium leaches out of the stalk so harvesting in the spring will result in less potassium removal from the field with an added benefit of having more soil cover over the winter. But loss of tonnage from weathering needs to be considered in this scenario.
Has the cost of nutrient removal gone into the pricing decision you’ve made on fodder baled off of a field?
Upcoming Events
Cover Crop Walks and Field Days
A number of cover crop demonstration plots have been established in various areas of the state to give farmers and crop advisors the opportunity to experience the performance of the cover crops this fall and interact with peers and specialists during these events to learn more about cover crops and their potentials. The field walk dates and locations of these demonstration plots can be found in this document: http://extension.psu.edu/field-crop-news/documents/covercrop-walks-fall-2011.pdf
Soybean Production Workshops
A series of soybean production workshops are scheduled for the week of December 11. Each workshop will feature Penn State researchers, experienced soybean growers, and county Extension personnel presenting information covering all aspects of soybean production from planting to harvest. Topics include how to get started in soybean production, soybean growth and development, weed and insect pest diagnostics, and best practices for harvest and storage. CCA and pesticide credits are available at each location.
The workshops will be held at the Franklin Ag Center in Chambersburg, Pa.on Tuesday, December 13; the Chester Romano 4-H Center in Honey Brook, Pa. on Wednesday, December 14; the Columbia Extension Office in Bloomsburg, Pa., on Thursday, December 15; and Giannilli’s II in Greensburg, Pa. on Friday, December 16.
The Soybean Production Workshops run from 10:00 a.m. to 2:00 p.m. at each location. There is a $10.00 fee to attend, which includes lunch. Pre-registration is required one week prior to the workshop. Information on agendas, speakers and pre-registration is available on the Penn State Extension website by selecting the “Events” tab at http://extension.psu.edu/lebanon or by contacting the Lebanon County Extension office at 717–270–4391.
Support for the workshops is provided in part by the Pennsylvania Soybean Board through the soybean check-off.
Contributors: County Educators: Paul Craig (Dauphin), Mena Hautau (Berks), Greg Hostetter (Mifflin), Jeff Graybill (Lancaster), Del Voight (Lebanon) Department of Crop and Soil Sciences: Bill Curran and Dwight Lingenfelter (Weed Management).
Editor: John Rowehl (York)
Real time pest and heat unit activity: http://agsci.psu.edu/news/spotlight/pa-pipe
Calendar of Events: http://extension.psu.edu/cmeg/events
If you have any questions or would like to suggest a topic, please contact your local Extension Educator.
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