Field Crop News

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

September 30, 2008    Vol. 08:30

IN THIS ISSUE:

• Weather Outlook
• Corn Leaf Diseases
• Alternate Sources of Nitrogen
• Measuring and Reducing Soybean Harvesting Losses
• Weekly Roberts Agricultural Commodity Reports

Weather Outlook — Paul Knight, Pennsylvania State Climatologist

A steady cool down is expected from Wednesday to Friday marked by 12-18 hour long episodes of clouds and scattered showers interspersed with mainly clear skies. Rainfall will be far from uniform, with most sections averaging a tenth of an inch or less. Northern counties have the best chance for higher rainfall. The period from Friday morning to Sunday morning should bring the first frosts to parts of the northern and central mountain-valley network. High pressure should dominate the state allowing the chilly air to moderate early next week, but a new disturbance from the upper Plains will likely bring showers either Tuesday or Wednesday.

Despite a cool start to the new month, we still expect October to average warmer than normal (though not as warm as last year) and this will be followed by a chilly November which may translate into an early and vigorous start to the lake effect snow season in the northwest and Laurel highlands. Latest indications point to a rather cold and snowy December.

Corn Leaf Diseases — Del Voight, Acting Grain Crop Specialist

Adapted from Purdue University Plan Pathology.

While corn leaf disease patterns are often more noticeable this time of year, it is too late to manage them. However it is wise to determine the hybrids performance in resisting plant diseases. The major rule in managing leaf diseases is similar to wheat, in that one strives to keep the leaf that feeds the ear clean of disease. Infections below that point typically have less of an impact on corn yield. Most if not all recommendations, particularly for no till corn, emphasize hybrid selection to manage diseases.

Applications during tasseling are also an option. I visited fields last week that had been sprayed for leaf diseases and it appears that there was no effect on the leaf disease this season on that hybrid. Data from across the east and Midwest is variable and the key to determine the need to treat is related to specific field conditions. In some studies with industry and universities, it appears that fields that have observable disease infecting the lower leaves, fields with hybrids that are prone to disease infection, and reduced tilled fields that are showing signs of infection are fields that may prove to return a profit. In some industry hybrids, 60% of hybrids showed a response above the economic return. Universities found that a fourfold response occurred in fields showing disease infection.

Most of the studies suggested an average of 8 bu/acre resulted in fields where a disease is present in the east. In the southern climates responses to a fungicide treatment of 15 bu/acre, were observed by Universities. The thresholds developed are based on typical crop markets. Current markets may certainly have changed but the key to the best response is the infield observation of what diseases exist and to what extent. From a practical stand point with the number of fields that were converted to no till this season, growers that utilized the same hybrid in two consecutive years should take a serious look at fungicide applications on corn. In Pennsylvania research is underway looking at the affects of fungicides on grain and also the silage impact as well. If one does choose to apply a fungicide read and follow label directions and be sure the application equipment can get high enough above the canopy to provide proper coverage.

	Disease Name: Gray Leaf Spot Pathogen: Fungus. Cercospora zeae-maydis Symptoms: Initial lesions appear as greenish black water soaked circular areas with chlorotic halos, expanding into oval and then the diagnostic parallel sided rectangular brownish gray lesions. Conditions: Infection is favored by extended warm, wet, humid weather. Inoculum Survival: Infected crop residue (leaves and leaf sheaths). Inoculum Dispersal: Airborne spores. Management: Select hybrids with resistance (tolerance based on risk), two year crop rotation, cleanly plow under infected residue.
	Disease Name: Anthracnose Leaf Blight Pathogen: Fungus. Colletotrichum graminicola Symptoms: Small, oval to elongated water-soaked lesions enlarge to become brown, spindle shaped spots with yellow to reddish-brown borders. Lesions may coalesce and blight entire leaves. Older lesions will turn gray in the center with small black specks (acervuli with sterile black hairs). Leaf blight may be followed by top kill and stalk rot. Leaf blight rarely causes large yield losses. Stalk rot phase is most important (see Anthracnose Stalk Rot). Conditions: Favored by cool to warm, wet, humid weather, continuous corn with reduced tillage. Inoculum Survival: Infected crop residue (leaves, leaf sheaths and stalks), seed (endosperm). Inoculum Dispersal: Airborne spores. Management: Resistant hybrids, rotate corn with nongrass crops. Cleanly plow under infected residue.
	Disease Name: Common Corn Rust Pathogen: Fungus. Puccinia sorghi Symptoms: Initial symptoms are chlorotic flecks on leaf surfaces. Flecks develop into oval to elongate reddish brown powdery pustules on upper and lower leaf surfaces. Reddish brown spores break through the leaf epidermis. Pustules become brownish-black as they mature. Usually not a serious disease in hybrids. Conditions: Disease favored by cool (66 F optimum) humid weather. Inoculum Survival: Spores blown into the Midwest from the South. Does not survive winter in Indiana, except possibly in rare years along the Ohio River. Inoculum Dispersal: Airborne spores. Management: Resistant hybrids. Foliar fungicides may be useful in seed production fields.
	Disease Name: Southern Corn Rust Pathogen: Fungus. Puccinia polysora Symptoms: Similar to common rust except pustules occur almost exclusively on the upper leaf surface, rarely on lower. Pustules are more orange than brick-red and slower to break through epidermis of leaf than common rust pustules. Conditions: Favored by high humidity and temperatures around 80 F. Inoculum Survival: Spores blown into the Midwest from the South. Does not survive winter in Indiana, except possibly in rare years along the Ohio River. Inoculum Dispersal: Airborne spores. Management: Resistant hybrids. Foliar fungicides may be useful in seed production fields.
	Disease Name: Northern Corn Leaf Blight Pathogen: Fungus. Exserohilum turcicum Symptoms: Long cigar-shaped gray-green or tan lesions. Conditions: Favored by extended wet, cool, humid weather, minimum tillage, continuous corn. Usually occurs during or after pollination. Inoculum Survival: Infected crop residue (leaves, husks, stalks). Inoculum Dispersal: Airborne spores. Management: Resistant hybrids. Foliar fungicides may be useful in seed production fields. Cleanly plow under infected residue.
	Disease Name: Northern Leaf Spot Pathogen: Fungus. Helminthosporium carbonum (Race 3) Symptoms: Narrow, small, linear to oval shaped leaf lesions. Lesion type may vary with the genotype of host and isolate. Lesions are grayish tan and surrounded by a light to darkly pigmented (usually purple) border. Chain-like leaf lesions are often produced. Conditions: Favored by moderate temperatures and high relative humidity, minimum tillage, continuous corn. Inoculum Survival: Infected crop residue (leaves, husks, stalks, seed). Inoculum Dispersal: Airborne spores. Management: Resistant hybrids. Disease is primarily a problem in seed production fields with certain highly susceptible inbreds. Foliar fungicides may be useful in seed production fields. Cleanly plow under infected residue.

Alternative Sources of Nutrients — Dr. Douglas Beegle, PSU Specialist - Soil Fertility

With the high fertilizer prices many farmers are looking for alternatives to traditional fertilizers to meet the fertility needs of their crops. There are some good options out there but there are also some concerns that need to be considered.

Take Care of the Basics

First, take care of the basics. Make sure you know what you need or don’t need. Soil testing is always important but especially so now with the high fertilizer and crop prices. Regardless of the price or the source, you can’t afford to apply nutrients you don’t need and you certainly do not want to limit yields because you cut nutrients too much because of the high prices.

Don’t Overlook Liming

It is a false economy to cut out liming because you are spending more on fertilizer. For optimum nutrient utilization, soil pH should be around 6.5. If you have to limit liming don’t do it arbitrarily, prioritize fields. In general, fields with a pH below 6 should be the priority fields for limestone applications. Remember, you never want to have fields for agronomic crops with a pH less than 5.5 because this is the critical pH for root growth. If you can’t afford the full rate of limestone, a partial rate is better than none on these low pH fields. Another priority would be fields being rotated into alfalfa that call for lime.

Manure Utilization

If there is manure on the farm, use it to maximize the return on those nutrients and thus reduce or eliminate the need for purchased supplemental nutrients. Use the manure on the fields that need N and have the lowest P and K soil test levels. Apply manure as close to the time of crop need as practical. If possible incorporate the manure to preserve the N. If the farm does not have an excess of manure, consider applying the manure at a lower rate but covering more ground based on meeting the P and/or K requirements of the crop. Account for the N supplied by the manure and then make up the N shortfall with fertilizer (for example sidedress N on corn). This type of strategy will maximize the efficiency of nutrient use for both the manure and the fertilizer.

Nutrient Content and Availability

There are many organic sources of nutrients potentially available off farm, such as manure, biosolids, composts, and spent mushroom soil. If used properly, these can be effective substitutes for fertilizer nutrients. If you are planning to use one of these sources make sure you know what you are getting.

Unlike fertilizer, these organic sources do not have a known nutrient content. Thus, it is absolutely critical to have an analysis of the actual material that will be used. Book values are good averages but are worthless in any individual situation. This is especially true for any treated material such as biosolids and composts. The analysis should include at a minimum: % Solids or Moisture, Total N, Ammonium N, Total P, and Total K.

Analysis of these materials is available from many agricultural labs such as the Penn State Agricultural Analytical Services Lab.

In addition to knowing the nutrient content of the material, it is also important to think about what else might be in the material. This is especially important for by-product materials. An example would be heavy metals in biosolids. Never use a material that you are not satisfied that it does not contain anything that is potentially harmful regardless of the price. Also, be aware that some of these materials may be regulated. This may provide assurance that the material is safe to use, but there may also be additional regulatory requirements associated with using these materials. If you do your homework and check out these materials many of them can be good, cost effective sources of nutrients, just make sure you know what you are getting.

In addition to knowing what is in the material, it is also important to determine the availability of the nutrients in these materials. Phosphorus and potassium are usually considered to be similar in availability to fertilizer P and K. Unfortunately, this can vary, especially for P in highly treated materials like biosolids.

Nitrogen availability is much more complex and can vary from as low as 15% to as high as 75% of the total N in the material. The actual amount of N that will be available to the crop will depend on when the material is applied, when the target crop will utilize the nutrients, whether the material is incorporated, and the type of material. Table 1.2-15 in the Penn State Agronomy Guide can be used with the analysis to estimate N availability. An example showing how to do this important calculation is also provided in the Agronomy Guide.

Because of the uncertainty associated with using organic sources of N, many farmers are uncomfortable with taking full credit for these nutrients, especially N. A common practice is to add some insurance fertilizer to cover this uncertainty. That may have been economical at one time but is very questionable with today’s prices. A better approach is to apply the organic nutrient sources based on the estimates of availability and then use the Pre-sidedress Soil Nitrate Test (PSNT) or the Chlorophyll Meter Test to determine if these sources are meeting the needs of the crop. If the test shows that N is not adequate, a sidedress N application can be made to correct the situation, but if the test indicates that they are adequate, then no additional fertilizer N is needed, thus eliminating the need for insurance fertilization. Details on these tests are available in Penn State Agronomy Facts #17 and Agronomy Facts #53.

Matching Nutrient Content with Crop Requirements

Realize with these organic materials, that the nutrient content may not match up exactly with crop requirements. The most common approach is to apply these organic materials to meet all of most of the available N requirements of the crop. See example calculations in the Penn State Agronomy Guide.

However, if most manures are applied to supply the bulk of the available N needs of a corn crop, there will usually be a significant amount of excess P and K applied above what the crop needs. Over time, with repeated applications, this can result in very high soil test P and K levels which could result in environmental or other problems.

A strategy adopted by some farmers who are importing manure as a nutrient source is to use manure at a rate that supplies the bulk of the N requirement of the crop for a year but only applying manure every two or three years. In the years between manure applications, the excess manure P and K are utilized by the crops and the annual crop N requirement is supplied with fertilizer N. When the soil test indicates the need for more P and K another manure application is made. With this strategy, every 2 or 3 years, they get 1 year worth of N, 2 or 3 years worth of P and K, and they do not risk building their soil test levels up into the very high range.

Another common example of the mismatch between nutrients in these organic sources and crop requirements is the generally, very low potassium content of biosolids. Many farmers think that biosolids are just like manure and have lots of all three: N, P, and K. However, in the sewage treatment process most of the K is in the effluent, not in the biosolids. When this is not recognized, crop K deficiency is common.

Importing Manure Regulations

When importing manure as a nutrient source, realize that there are regulations in PA addressing importing manure from regulated farms that will impact many farmers who import manure. There was an article on this subject in the September 23, 2008 edition of the Field Crop Newsletter.

A final note on using these organic sources of nutrients is that equipment must be calibrated to apply the appropriate rate to balance the crop nutrient requirements with the nutrients in the material. A new factsheet describing this procedure, Agronomy Facts #68, “Manure Spreader Calibration” is available from Penn State Cooperative Extension.

Other Non-Traditional Materials

While most of the questions lately have been about using these organic sources as substitutes for fertilizer, there are other non-traditional products being sold as fertilizer replacements or enhancers. Some of these are legitimate while others are not. It can sometimes be difficult to sort through the sales information to figure this out.

If you are considering using a non-traditional nutrient source or fertility enhancer, do your homework, ask about mode of action, look for unbiased research results, and be suspicious of unwritten claims, testimonials, and too-good-to-be-true claims. A regional committee on Nontraditional Soil Amendments and Growth Stimulants (NCR-103) has reviewed many of these products and compiled a summary of products, companies, ingredients, and claims that is available on the web. They have also produced a Compendium of Research Reports on Use of Non-Traditional Materials for Crop Production that is also available on the web. These can be very useful resources when you are considering use of these non-traditional products.

Fertilizer Claims

Finally, even if you are not looking for substitutes for fertilizer as a nutrient source, be aware of questionable claims made about some fertilizer materials.

An example is the claim that is sometimes made that a few gallons per acre of a particular liquid fertilizer is equivalent to several hundred pounds of a dry fertilizer. In most cases, a liquid or dry fertilizer with similar analysis will have similar availability. Also, some simple math will show that if a plant needs the 60 to 80 lbs of nutrients contained in a common dry fertilizer, substituting 3 gallons of a common liquid fertilizer which only contains 10 to 15 lbs of nutrients, cannot possibly meet the needs of the crop regardless of the availability of the nutrients. Applied at rates that supply the quantity of nutrients needed by the crop, both liquid and solid fertilizers will be effective. The most important thing is to buy high quality fertilizer (liquid or solid) from a reputable dealer.

Measuring and Reducing Soybean Harvesting Losses, Del Voight — Interim Grain Crop Specialist

Adapted from the fact sheet that Charles W. Shay, Lyle Ellis and William Hires produced from the Missouri Department of Agricultural Engineering

Over the last several years of working with what I consider the top soybean producers in the region, I have learned the importance of timely harvest of soybeans. In one case during a soybean contest harvest, we took the harvest early and then finished the field three weeks later. As a result there was about a 20 bushel per acre difference in a three week period! Further, just last year I was asked to check a field and even before the combine entered the field I measured 12 bushels per acre on the ground from premature shattering. Again, it was a delay harvest of three weeks.

It has been my experience that once 95% of the leaves turn brown about a week later it’s time to combine. That may mean some green leaves are still on the stalk. I still remember John Yocum referring to the fact that after the plants first reach harvestable moistures, dry matter losses occur simply by the alternating day and night. I found the following excerpts from a Missouri article useful during harvest to capture the losses that may occur during harvest.

Numerous tests of soybean combine losses show that up to 12 percent of the soybean crop is lost during harvest. Harvesting losses cannot be reduced to zero, but they can be reduced to about 5 percent. Combines can be operated to reduce losses without affecting the harvesting rate. This guide describes the major sources of loss. Consider shatter losses of 2 percent acceptable. Average losses are 5 percent or more.

Tips for keeping combine losses low

Your best guide for correct combine adjustment is your operator's manual.

Remember that more than 80 percent of the machine loss usually occurs at the gathering unit. The following suggestions will help keep these losses to a minimum.

• Make sure that knife sections, guards, wear plates and hold-down clips are in good condition and properly adjusted.
• Use a ground speed of 2.8 to 3.0 miles per hour. To determine ground speed, count the number of 3-foot steps taken in 20 seconds while walking beside the combine. Divide this number by 10 to get the ground speed in miles per hour.
• Use a reel speed about 25 percent faster than ground speed. For 42-inch-diameter reels, use a reel speed of 11 revolutions per minute for each 1-mile-per-hour ground speed.
• Reel axle should be 6 to 12 inches ahead of the cutter bar. Reel bats should leave beans just as they are cut. Reel depth should be just enough to control the beans.
• A six-bat reel will give more uniform feeding than a four-bat reel.
• Complete the harvest as quickly as possible after beans reach 15 percent moisture content.
• A pick-up type reel with pick-up guards on the cutter bar is recommended when beans are lodged and tangled.

Weekly Roberts Agricultural Commodity Market Report - Mike Roberts, Commodity Marketing Agent, Virginia Tech — Submitted by Andrew Frankenfield, Montgomery County Educator

September 30, 2008

With the exception of the May ’09 Lean hog contract commodity prices were stridently lower across the board on Monday amid concerns over uncertainty that the U.S. House would reject the government bailout proposal. In these volatile times it seems the chart signals and fundamentals are at the mercy of politicasters and an economy that, according to Greenspan was once quite “exuberant.”

Don’t know if a quote by Laurel and Hardy is seen much in a market report but I feel it appropriate to say to someone, “Well, here’s another nice mess you’ve gotten me into!” — Oliver Hardy in Another Fine Mess (1930)

CORN futures on the Chicago Board of Trade (CBOT) finished limit down on Monday. The DEC’08 contract closed at $5.130/bu, down 30.0¢/bu from Friday and 45.5¢/bu lower than a week ago. MAR’09 corn futures closed at $5.310/bu; off 30.0¢/bu and 45.25¢/bu lower than this time last Monday. The 30.0¢/bu trading limit will be increased to 45.0¢/bu for Tuesday’s trading. Spillover uncertainty about U.S. and world economic outlook amid good crop weather and no prospects for frost in the near future pressured commodities. However, not all is gloomy, near the end of trading cash bids for corn strengthened because of end-user interest in these lower prices. Late Monday USDA put the U.S. corn crop at 9% harvested vs. a 21% 5-year average for this time of year and 29% rate this time last year. Corn-inspected-for-export was placed at 40.164 mi bu vs. 28-32 mi bu due to a weakened U.S. dollar. CFTC’s Commitment of Traders report dated 9/23 had large speculators increasing net bull positions by 12,200 to 62,927 lots. The next report will most likely show a decrease in net bull positions as funds sold between 7,000 and 8,000 lots as they liquidate positions while the money flows out of financial markets. Those who have up to 70% of the ’08 crop priced today are in good shape.

SOYBEAN futures on the Chicago Board of Trade (CBOT) finished limit down on Monday. NOV’08 soybean futures closed at $10.940/bu, off 70.0¢/bu and $1.11/bu lower than last Monday. The JAN’09 soybean contract closed at $11.100/bu; off 70.0¢/bu and $1.12/bu lower than a week ago. Tuesday’s trading limit will expand to $1.05/bu. Soybeans-inspected-for-export were placed at 7.524 mi bu vs. estimates for between 7-11 mi bu. Crop weather is encouraging for the U.S. Midwest soybean crop. USDA placed the U.S. soybean crop at 9% harvested vs. a 24% harvested rate this time last year and a 21% -5-year average. The market did not expect to see much of a harvest figure reported. As with corn, the CFTC Commitment of Traders report as of 9/23 showed large speculators increasing net bull positions by 4,600 lots to 22,318 contracts. This kind of action may not hold up as funds sold 5,000 contracts and liquidity leaves those markets. Synthetic trading and speculative long liquidation were the elements of the day. November ’08 futures synthetically traded a range of $10.85/bu - $10.90/bu according to some floor sources. Futures are said to trade synthetically when a position is created by combining call and put options for the purpose of mimicking the payout schedule and characteristics of a futures contract. A synthetic long futures contract is created by combining long calls and short puts. A synthetic short futures contract is created by combining short calls and long puts. In order for both combinations to be identical to a futures position, the options must have the same expiry dates and strike prices. This kind of trading predominates when traders are looking to avoid a huge initial investment while managing risk. Synthetic futures are said to provide an opportunity to manage risk without “betting the farm.” With these volatile prices it is good if you have priced 60% of the ’08 crop already.

WHEAT futures in Chicago (CBOT) closed down on Monday. The DEC’08 contract closed at $6.680/bu, off 48.0¢/bu from last Friday and 69.75¢/bu lower than a week ago. JULY’09 wheat futures were down 45.5¢/bu at $7.160/bu and 66.25 cents lower than this time last week. Increasing economic fears pressured U.S. and global wheat markets. Wheat-inspected-for-export was placed at 22.196 mi bu vs. expectations for between 22-26 mi bu. News that Argentina’s wheat crop was suffering drought stress was supportive for prices. However, better wheat-crop weather forecasts were in the making for Australia’s wheat crop. The CFTC supplement on Friday showed large speculators reducing net bear positions in CBOT wheat by 4,000 lots to 35,741 contracts as of 9/23. Funds sold 4,000 contracts. As with all the markets, traders said they were watching the U.S. Congress rejection of the $700 billion bill to liberate the financial industry from the deluge of bad debt amid ever shrinking credit lines. According to Dan Basse, president of AgResource Co., “The fundamentals are out the window. It’s all about credit lines and index and hedge funds getting out, and crude oil.” Crude oil was down $9/barrel. It would be a good idea to get up to 10%-20% of the ’09 wheat crop priced.

Full Report is available at http://www.ext.vt.edu/news/periodicals/roberts/2008wp/Sept30_2008.html

For a specific methods and sheet to take to the field refer to this publication and enter your own information. You may also call me directly for copy to have on hand.

If you want additional information on setting up a combine for corn or soybeans take a look at this article out of Iowa State.

Contributors: Extension Educators: Susan Alexander (Jefferson), Paul Craig (Dauphin), Andrew Frankenfield (Montgomery), Kevin Fry (Armstrong), Joel Hunter (Crawford), Jonathan Rotz (Cumberland), Del Voight (Lebanon and Interim Grain Specialist) Department of Crop and Soil Sciences: Dr. Doulas Beegle, Dr. William Curran

Editor: Mena Hautau

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