Field Crop News at Penn State

Field Crop News

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

August 13, 2004    Vol. 04:09

IN THIS ISSUE:

Mark Your Calendar

Announcements

Production

Pest Management

Agents Corner

ANNOUNCEMENTS

NEW SOIL MANAGEMENT WEBSITE

Check out the soil management website at http://soilmanagement.psu.edu. There is information on upcoming conferences and extension meetings, and you will find links to many different sources of soil management information.

Sjoerd Duiker, swd10@psu.edu
Soil Management, Crop and Soil Sciences

PRODUCTION

PROPOSED NUTRIENT MANAGEMENT REGULATIONS UPDATE

In the last newsletter I wrote about the pending publication of proposed changes to the State Nutrient Management and CAFO regulations. These regulations were published in the Pennsylvania Bulletin on August 7, 2004. You can find the official proposed changes to the Nutrient Management Regulations at: http://www.pabulletin.com/secure/data/vol34/34-32/1474.html and the CAFO regulation changes are at: http://www.pabulletin.com/secure/data/vol34/34-32/1473.html .

Both of these proposals are open for public comment until November 5, 2004. To facilitate comments Penn State Cooperative Extension has prepared two factsheets that explain the proposed changes and provide guidance for anyone who would like to make comments. Click here to go to the factsheet on the Nutrient Management Regulations: Shaping New Pennsylvania Nutrient Management Act Regulations: A Guide to the Proposal and Comment Process or here for the CAFO regulation factsheet: Make Your Voice Heard: Commenting on Proposed Water Pollution Regulations for CAFOs and Other Agricultural Operations. Hard copies of these publications will be available in County Extension Offices by September 1, 2004. For more information go to the Nutrient and Water Policy web page at: http://agenvpolicy.aers.psu.edu/GetInvolved.htm

The changes proposed in these regulations will have an important impact on animal agriculture in Pennsylvania. Thus, it is critical that anyone with a stake in nutrient management take the time to learn about these proposed changes and take advantage of the opportunity to provide input on the proposals before they become final regulations.

Douglas Beegle, dbb@psu.edu
Soil Fertility and Nutrient Management, Crop and Soil Sciences

LATE SEASON CORNSTALK NITRATE TEST AVAILABLE THROUGH THE PENN STATE AGRICULTURAL ANALYTICAL SERVICES LABORATORY

Nitrogen (N) management is one of the most difficult decisions in corn production because of the many factors that influence N behavior including: materials, timing, weather, etc. This is especially true when manure is part of the system. Standard recommendations try to account for many of these variables and early in-season tests such as the Pre-sidedress Soil Nitrate Test (PSNT) and Chlorophyll Meter test are very helpful in reducing the uncertainty in N recommendations. While we can never totally eliminate this uncertainty, with experience we can minimize it. A key to improving N management over time is having reliable feedback on how well your N management is working. Good yields and dark green plants are certainly good indicators of adequate N but they to not tell us if we have too much N, which can be a problem especially with manure. Also, some visual symptoms of N deficiency late in the season may not always indicate a yield loss.

The Late Season Corn Stalk Nitrate Test has been shown in research at a number of locations, including across PA, to be a reliable end of season indicator of crop N status. It provides a good assessment of whether the crop had the right amount of N or too much N or whether it ran out of gas. This information combined with records of N management can be very useful for making future management decisions.

To do this test, 8-inch long sections of corn stalk (subsequently cut into two inch long segments) are taken starting 6 inches above the ground. Pruning shears usually work well for taking these samples. Stalk sampling can be done anytime between about the 1/4 milkline stage of the grain, which is just before silage harvest, and up to 3 weeks after the grain forms a blacklayer. If possible, dry the samples immediately or send them to the lab as soon as possible after collection. If there is more than a day between sampling and sending, refrigerate (don't freeze) the samples until you can send them. Keep the samples in paper (not plastic) bags. While you could test all fields, testing a few representative fields will probably be adequate to provide a good assessment of your N program.

This test is now available through the Penn State Agricultural Analytical Services Laboratory (AASL). The cost of this test is $10. Information about the test including sample submission forms and detailed sampling instructions are available on the AASL web site at: http://www.aasl.psu.edu. Results of this test provide a good assessment of the adequacy of the nitrogen management in a field and can be very helpful in adjusting management in the future.

Douglas Beegle, dbb@psu.edu
Soil Fertility and Nutrient Management, Crop and Soil Sciences

COVER CROP OPTIONS FOR THE FALL

Small grains should be harvested by now, and corn and soybean harvest season is starting shortly. Thus it is time to think about cover crops. Cover crops can be used for different purposes: Soil protection over the winter, additional forage production, nutrient uptake and protection from leaching, soil improvement by adding above and below-ground crop residue, nitrogen fixation, weed control and mulching for next year's no-till crop. The purpose will determine the type of cover crop, and it may even be possible to mix some cover crops together to meet various goals. Where you are located as well as establishment time will also influence cover crop options. Over the past two years we have evaluated the effect of establishment and termination date of seven promising cover crops in central and southeastern Pennsylvania: annual ryegrass,cereal rye, winter wheat and winter barley, hairy vetch, crimson clover and rape. The cover crops were established middle of September, early October, and middle of October. Dry matter production was determined early May, middle of May and early June.

Winter hardiness of these cover crops decreases as follows: rye>wheat>ryegrass>barley>hairy vetch>rape>crimson clover. Biomass produced varied depending on the type of winter. The fall of 2002 was very wet and cold, thus we were not able to get our cover crops established mid-October in Central PA. The winter of that year was also very cold without a lot of snow cover, leading to the demise of most cover crops in central PA except for winter rye, ryegrass and winter wheat. The past fall was milder and not as wet, thus we were able to get all of our cover crops established as planned. Although the winter was also cold there was more snow cover and therefore the cover crops did better. The following management recommendations can be made for the cover crops evaluated.

Ryegrass
Annual Rye Grass

Ryegrass is an excellent nutrient scavenger and provider of mulch if not killed too early. It produces a fine, fibrous root system that helps improve soil structure. It can become a weed problem if it is allowed to set seed. When established mid-September in southeastern PA, ryegrass will produce about 1 T/A dry matter by early May, up to 3.5 T/A early June if the winter is not too cold. In central PA, dry matter production will be 0.7 T/A early May up to 2.3 T/A early June. It is possible to establish annual ryegrass up to mid-October in southeastern PA, but in central PA ryegrass should really be established before October to achieve satisfactory performance as a cover crop. Ryegrass seeding rate is 25 lbs/A. The cost is $0.30-0.40 per pound.

Cereal rye
Cereal rye

Cereal rye is our most winter hardy cover crop. It is an excellent nutrient scavenger and provider of residue cover. It produces a fine, fibrous root system that helps improve soil structure. It is also used as a forage crop. Rye grows very rapidly in the spring, and therefore it can become challenging to kill it on time. When established mid-September in southeastern PA, rye will produce about 2-3 T/A dry matter by early May, up to 5 T/A early June. In central PA, dry matter production will be about 2 T/A early May up to 3.5 T/A early June. It is possible to establish cereal rye even after mid-October in southeastern PA, but in central PA cereal rye should be established by mid October to achieve satisfactory performance as a cover crop. Rye should be seeded at a rate of 2 bu/A. The cost is about $8-9 per bushel.

Winter wheat
Winter wheat

Winter wheat is an excellent nutrient scavenger and residue provider. It produces a fine, fibrous root system that helps improve soil structure. It is not as vigorous as rye and therefore easier to manage in the spring. When established mid-September in southeastern PA, wheat will produce about 1.5 T/A dry matter by early May, up to 2.7 T/A early June. In central PA, dry matter production will be 1 T/A by early May up to 2.3 T/A early June. It is possible to establish winter wheat up to mid-October in southeastern PA, but in central PA winter wheat should be established by early October to achieve satisfactory performance as a cover crop. Winter wheat seeding rate is 2 bu/A. The cost is about $6 per bushel.


Barley
Barley

Barley is less full-proof compared to rye and wheat. In the winter of 2002/03 it only partially survived in southeastern PA, and completely winter-killed in central PA. The cost of barley seed is very high: $15.50 per bushel. The seeding rate is 2 bu/A. Barley is therefore less suitable than the other small grains rye and wheat as a cover crop.


Hairy vetch
hairy vetch

Hairy vetch is known to be the most winter hardy annual legume available. It fixes nitrogen that can be used by the following crop. Hairy vetch grows rather slowly in the fall, but rapidly in April/May, when it fixes about 1 lbs/N/A per day. Hairy vetch needs to be established by mid-September in southern PA and by mid-August in central PA. When established mid-September in southern PA, hairy vetch will produce about 1 T/A dry matter by early May, up to 2.7 T/A early June. In central PA, dry matter production will be 1 T/A early May up to 1.9 T/A early June. Hairy vetch contains about 60 lbs N/ton. It creates long vines that can climb into standing small grain. The vines are quite succulent and decompose rapidly once killed. A very nice cover crop mix is 1 bu/A rye plus normal rate of hairy vetch. The rye will provide winter cover, and the vetch will start climbing into the standing rye. Nitrogen fixation has been shown to be the same with the rye as without it. Hairy vetch seeding rate is 25 lbs/A, at a cost of approximately $1.25 per pound.

Crimson clover
crimson clover

Crimson clover is a legume that fixes nitrogen. It grows faster in the fall compared to hairy vetch. We have been very pleased with crimson clover survival in the last two winters in southeastern PA. When established by mid-September, crimson clover will produce about 1.5 t/A of dry matter early May up to 3.3 t/A early June. One ton of crimson clover contains about 50 lbs of N. Crimson clover produces rather tough stalks that may be hard to cut through in the spring. Crimson clover is not suitable for central PA and needs to be established by mid-September in southern PA. Seeding rate is 20 lbs/A at a cost of $1 per pound.


Rape
rape

We have been evaluating rape because of its tap root. The idea being that the taproot can help alleviate soil compaction. Rape did well in southern PA when established by mid-September. In central PA it did not survive the 02/03 winter, even if established mid-September. When established mid-September in southeastern PA, rape will produce about 1.5 T/A dry matter by early May, up to 3 T/A early June. Rape needs to be terminated mid-May or it may set seed which can become a weed problem. The stalks are very tough when rape starts flowering. Rape may not survive the winter in central PA. Seeding rate is 10 lbs/A at a cost of approximately $0.55 per lbs.

Sjoerd Duiker, swd10@psu.edu
Soil Management, Crop and Soil Sciences

Pest Management

SOYBEAN RUST: STATUS REPORT AND EFFORTS TO PREPARE FOR INTRODUCTION

Soybean rust is a serious foliar disease in soybeans in many parts of Asia. In 2001 the disease was detected in South America, and has become wide spread in Brazil and northern Argentina. The disease is reported to cause yield losses ranging from 10 to 80%. If soybean rust finds it's way to the U.S. it may quickly become a major limitation to soybean production in some areas. However, let me make this very clear.....To date, soybean rust has not been reported in the continental U.S.

Rapid and accurate diagnosis will be critical for initiating our efforts to manage soybean rust if and when the disease arrives here in the U.S. The United States Department of Agriculture (USDA) has been working with representatives from State Department of Agriculture and University personnel to make sure that infrastructure and training required for a rapid diagnosis of soybean rust is in place.

At this time we do not know for certain where the rust fungus can survive the winter in the U.S. However, research from Iowa State University indicates the pathogen is likely to survive only in southern most points in States such as Florida and Louisiana in association with Kudzu or other legumes. In the spring the pathogen will likely be brought to northern states by wind. The timing of the annual introduction of the pathogen, and local weather conditions will influence the severity of disease at a given location.

Outlook on Management

USDA scientists have evaluated all soybean varieties currently grown in the U.S. and found no resistance to soybean rust. Only a few genes are known to provide high levels of resistance to soybean rust, but these genes can already be overcome by the diverse race structure of the pathogen population. Breeding efforts are underway and will likely focus on finding varieties that slow the development of the disease. This type of resistance is effective against all races and tends to be stable for long periods of time. It will likely take years to develop resistant varieties that have acceptable agronomic qualities.

Fungicides are likely to be a significant tool in the management of soybean rust. Data from the USDA suggests that many fungicide products can be effectively used to manage soybean rust. Currently only a limited number of products are labeled for use on soybean including Quadris and Bravo. The Pennsylvania Department of Agriculture and Penn State have worked together to submit applications to the EPA for Section 18's covering additional fungicide products. Some of these applications have been approved, but application of Section 18 products remains illegal until the USDA has confirmed soybean rust in the continental U.S. However, when needed, these products will increase the number of tools available for rust management.

Penn State has also joined a national effort to develop extension materials for soybean rust including diagnostic guides and a manual on fungicide applications to soybeans. We hope to have many of these resources available in time for the 2005 growing season.

You can find additional information on soybean rust symptoms and management on line at: http://www.aphis.usda.gov/ppq/ep/soybean_rust/

Erick De Wolf, dewolf1@psu.edu
Plant Pathology

Agents Corner

CAPITAL

Corn silage harvest is just around the corner. In some areas producers have started to open up fields and build a pile of transition silage this week. In hybrid evaluation plots in Landisville most mid-seasoned, 100 day corns have started to dent. On August 5 at the beginning of denting whole plant moistures were 78%. On August 12 moistures had dropped by 2% to 76%. Now the ears are well dented. Estimates of whole plant dry down rates are typically in the 0.5% per day after denting. They are many environmental and plant physiological processes that affect this rate. However the trend downward of our silage crop and the critical need to make harvest starting decisions at proper plant moistures make this an important task for all silage producers. Harvesting at correct moisture levels sets the stage for maximizing potential milk yields per ton of corn silage.

Concerns have been raised by silage producers this week about the potential for existing molds, yeasts and fungi on the corn crop due to wet humid growing conditions this year. Alternatives mentioned include proprionic acids, buffered proprionic acids and silage inoculants containing lactobacillus buchneri bacteria. These products have proven to have many beneficial affects on silage quality in many feeding studies. However; proper harvesting and storing practices have significantly greater affect on silages. Bunker silos require "more than adequate" weights of packing equipment. Proper density of the pack minimizes dry matter losses and possible mold and yeast development.

Discussion was also heard this week regarding high chop verses traditional chop silage harvest. Points to consider before making this decision include:

Otherwise our grain crops look excellent. Many signs of fields running out of nitrogen are being evident. Most fields with manure application histories are maintaining optimum nitrogen levels. Frequently fertilizer fields do not appear to have sufficient nitrogen available. I was recently informed of a soybean field near Halifax, with symptoms of a stem canker disease. Two strains, Northern and southern, Positive identification has not occurred this year. Field has a dullish cast to it, stems have noticeable reddish brown shrunken areas. Many plants these have encircled the stem. When split open the stem is discolored and hollow. Introduction of disease is related to cooler, wetter conditions in the V1 to V7 stage. There is some inherent resistance, but under optimum conditions for the disease this may not always be sufficient. There will be a greater risk of early lodging I am certain. I am wondering if there are additional fields with stem canker around??

Paul Craig, phc8@psu.edu
Dauphin County

NORTHWEST

Generally, we have had hazy, warm and humid weather for the last couple of weeks with scattered showers and thunderstorms. Farmers are finishing wheat harvest, starting oats and baling straw this week. The corn looks very good in most areas, although some yellowing on the lower leaves can be seen in places. Early planted corn is in milk to late milk stages. There's corn in all stages since plantings were so difficult to make on time in the spring.

Soybean growth has been generally good as well. Some early planted fields are in the pod filling stage. Looks like a good yield possibility for beans.

Second and third cuttings of hay are being made between showers. Dry hay harvest still remains a challenge, as there just haven't been many dry days grouped together to allow for much dry hay to be harvested. Wrapped hay and bags of haylage are showing up all around the area. This will be another challenging year for farmers feeding livestock.

Pastures that haven't been overgrazed continue to stay green and growing with all the moisture that has been available.

Nelson Smith, nes2@psu.edu
Clarion County

SOUTHWEST

And the rainy season continues…July ended wet and August is following suit. Farmers are having a difficult time making hay this year. I was talking with a farmer over the weekend of the 7th, he was finishing 2nd, starting 3rd, and had abandoned some 1st that never got made. On the bright side, pastures have maintained their production with the cool, wet spring-like weather.

Overall the corn crop looks to be very good, except for the poorly drained areas. Some farmers are excited for corn harvest; they are looking to break some personal on farm records this year. However, there are a number of late planted fields that have yet to tassel and are in jeopardy of not making it to maturity with the slow accumulation of heat units this summer.

Beans are also looking very good, I expect there will be a few 60 bushel fields out there this year. Soybean aphid populations have been very low in fields I've scouted. Some downy mildew is showing up but no reports of white mold yet.

Kevin Fry, ksf107@psu.edu
Armstrong County


Beegle signature

Douglas Beegle, editor,
Professor, Agronomy, dbb@psu.edu

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