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July 30 August 5, 2002
C.O.R.N. C.O.R.N. 2002-24
In This Issue:
A) Drought-Stressed Corn For Silage
B) Crop, Forage, And Livestock Drought Information Available
At Osu
C) Assessing The Impact Of Drought On Corn
D) Will Root Lodged Corn Recover?
E) Use Of Corn And Soybeans For Silage, Etc - Herbicide Restrictions
F) Corn Insect Update
G) **Correction In Last Weeks Newsletter**
H) Bean Leaf Beetle On Soybean
I) 2002 Farm Bill Information And Program Payment Calculator
J) Changing Methods Of Reporting Ccc Loans
K) Farm Focus '02
Much of Ohio is under drought conditions and producers are concerned about chopping corn for silage. Below are some answers to common questions.
Q. When should I chop corn for silage?
A. It depends! The most important factor affecting when to chop corn is its dry matter concentration. Corn chopped too wet ferments very poorly and feed intake is reduced greatly when it is fed. Corn chopped too dry ferments poorly, has low starch digestibility and spoils quickly during feed out. Corn should be chopped when its dry matter is between about 30 and 40% (equal to 60 to 70% moisture). Ideally the dry matter should be between 32% (for bunkers) and 38% (for upright silos). Do NOT chop corn for silage when its dry matter is less than 28%. Feed intake by cattle is usually much lower when fed very wet silage. Before a farmer starts to chop, he should go to the field and cut a few (3 or 4) stalks at the same height as he plans on setting the chopper. Cut the stalks into small pieces (about 1 inch) using a cleaver or heavy knife, mix the sample and then analyze the sample for dry matter using a Koster tester or microwave (see OSU Agronomy Fact Sheet AGF-004-90). If the corn has the correct dry matter, he can chop the field. If it is too wet, delay chopping.
Q. What about nitrates?
A. See Animal Science Fact Sheet AS-0003-90 for more details. Drought-stressed corn often accumulates nitrates. Nitrates are toxic to ruminants. This year all corn silage should be tested for nitrates before feeding. Nitrates are often not a problem during prolonged drought but can become very high when prolonged drought is followed by rain. After a rain, the soil nitrates move into the plant. Silage fermentation usually reduces the concentration of nitrates in silage. Fresh plants can have excessive nitrates but the resulting silage might be safe to feed. Therefore, knowing the concentration of the feed after fermentation is more important than knowing the concentration of nitrates in fresh corn plants. It nitrates are suspected, sampling fresh material can be useful however. Before chopping starts, sample a few plants from the field (cut at the same height as the chopper) and send in the sample. If values are low, you should have no problem. If values are high, chopping height should be increased because most of the nitrates are in the lower portion of the stalk. Guidelines for nitrate concentrations are below (make sure the lab values are in the same units)
<0.1% Nitrate-N (dry matter basis): Feed is safe
0.1 to 0.2% Nitrate-N (dry matter basis): Feed is probably safe, limit to no more than 50% of the diet for pregnant animals
0.2 to 0.35% Nitrate-N (dry matter basis): Do not feed to pregnant animals, limit to less than 50% of diet for other animals
>0.35% Nitrate-N (dry matter basis): High risk, should not be fed.
Q. Are there any human health concerns?
A. Yes. High nitrate corn when put into a silo produces large amounts of gases. These gases (mostly nitric oxides) can be lethal. If you see a yellow-orange gas cloud around a silo, keep humans and animals away from it.
Q. Are silage additives useful with drought-stressed corn?
To reduce nitrate concentrations, a rapid and active fermentation is needed during silage making. A good quality silage inoculant might help increase fermentation which could lower nitrate concentrations. On the other hand, acids and ammonia reduce fermentation and should probably not be used for drought-stressed corn.
Q. What is the feeding value of drought-stress corn?
A. Assuming it was chopped at the correct dry matter and is low in nitrates, drought-stressed corn silage is a reasonably good feed for cattle. It usually has more fiber and less grain than normal silage but the fiber is usually more digestible. The net result is that the energy value is usually slightly lower than normal silage and additional grain supplementation might be needed. Drought-stressed corn silage must be tested for nutritional value so that appropriate diet changes can be made.
Industry face for their business decisions. A drought resource web site has
been
created that may be useful to help with decisions about crops, forages,
livestock and marketing at: http://corn.osu.edu/drought02
A mailing list with connection to Extension professionals has also been
created to help any questions related to drought at: (drought@ag.osu.edu).
Many corn growers want to know what impact drought stress has had on corn pollination, the stage in corn development most sensitive to such stress conditions. When severe drought stress occurs before and during pollination, a delay in silk emergence can occur. Sometimes the length of this delay is such that little or no pollen is available for fertilization when the silks finally appear. When such delays in silking are lengthy, varying degrees of barrenness will result. This year it's very likely that silk emergence will be delayed in many drought-stressed corn fields unless we get some significant rain very soon.
There are two techniques commonly used to assess the success or failure of pollination. One involves simply waiting until the developing ovules (kernels) appear as watery blisters (the "blister" stage of kernel development). This usually occurs about 1 1/2 weeks after fertilization of the ovules. However, there is a more rapid means to determine pollination success.
Each potential kernel on the ear has a silk attached to it. Once a pollen grain "lands" on an individual silk, it quickly germinates and produces a pollen tube that grows the length of the silk to fertilize the ovule in 12 to 28 hours. Within 1 to 3 days after a silk is pollinated and fertilization of the ovule is successful, the silk will detach from the developing kernel. Unfertilized ovules will still have attached silks.
Silks turn brown and dry up after the fertilization process occurs. By carefully unwrapping the husk leaves from an ear and then gently shaking the ear, the silks from the fertilized ovules will readily drop off. Keep in mind that silks can remain receptive to pollen up to 10 days after emergence. The proportion of fertilized ovules (future kernels) on an ear can be deduced by the proportion of silks dropping off the ear. Sampling several ears at random throughout a field will provide an indication of the progress of pollination.
The following are some recent observations and comments of Bob Nielsen, the corn extension specialist at Purdue Univ. regarding the potential for delays in silk emergence in some drought stressed fields
"What caught my eye this week in several fields was the appearance of
ears with unusually long fresh (unpollinated) silks. ....The good news is that
unpollinated silks will continue to elongate for about 10 days after they first
appear from the ear husks before they finally deteriorate rapidly. The bad news
is they do become less receptive to
pollen germination as they age and the rate of kernel set success decreases
towards the end of the 10 days.
Unusually lengthy silks that are still "fresh" during the pollination period are therefore a symptom that pollination has not been successful. Drought-stressed fields exhibiting visibly long fresh silks should be inspected for possible pollination failure."
Check out Bob's article, "Some Droughty Fields Experiencing Silk Emergence Delay", for more on this subject plus images showing this problem at: URL: http://www.kingcorn.org/news/articles.02/SilkDelay-0726.html
Strong winds and heavy rains associated with severe thunderstorms can lodge or knock corn plants over, especially if the nodal root system is not fully developed. The recent hot, dry weather conditions and soil compaction have inhibited good nodal root formation and predisposed plants to such wind injury. Strong winds can pull corn roots part way out of the soil; a condition referred to as root lodging. The problem is more pronounced when soil are saturated by heavy rains accompanying winds. If root lodging occurs before mid-grain fill, plants usually recover at least partly by "kneeing up." This results in the characteristic gooseneck bend in the lower stalk with brace roots providing above ground support. If this stalk bending takes place before pollination, there may be little effect on yield. When lodging occurs later in the season some yield decrease due to partial loss of root activity and reduced light interception may occur. If root lodging occurs shortly before or during pollen shed and pollination, it may interfere with effective fertilization thereby reducing kernel set. Hybrids differ in their ability to resist root lodging.
In a University of Wisconsin study, root lodging was simulated by saturating soil with water and manually pushing corn plants over at the base, perpendicular to row direction. Wind damage was simulated at various vegetative stages through silking (V10 to R1). Compared to hand harvested grain yields of control plants, grain yield decreased by 2 to 6%, 5 to 15% and 13 to 31% when the lodging occurred at early (V10-V12), medium (V13-V15) and late (V17-R1) stages. Keep in mind, however, that these results were obtained under more favorable conditions than we are experiencing in may drought stressed areas of Ohio. Severely stressed plants may be less resilient to wind injury.
Dry weather and poor crop conditions may force the use of soybeans and corn for silage/forage in some areas of the state. Most corn herbicide labels allow this use of corn. The time that must elapse between herbicide application and harvest of corn for silage, etc ranges from none to 85 days, depending upon the herbicide(s) applied. Corn herbicide restrictions are listed on page 61 of the current OSU Weed Control Guide. Soybean herbicide labels are more restrictive, and most do not allow use of soybeans for forage. Some labels do not have any information on the use of soybeans for forage, and we assume this indicates a lack of approval for this use. Soybean herbicide labels that allow this use of soybeans are as follows (with days between application and harvest):
Basagran 30 days
FirstRate/Amplify 14 days
Glyphomax 14 days
Roundup UltraMax 14 days
Sencor 40 days
Lodged Corn - We are seeing and hearing about corn fields that have problems
due to lodging. The primary cause for the lodging in most fields is environmental
conditions (too much rain, compaction, etc.) this past spring. There is some
evidence that rootworm larval feeding is also adding some damage to the already
less than desirable root systems. This rootworm damage is occurring in first
year corn and is being reported from some northwestern and west central Ohio
counties.
The first year corn rootworm (FYCR) problem is caused by the western corn rootworm
beetles (WCR) laying their eggs in soybeans fields in 2001. We have been monitoring
soybean fields for WCR since 1998 and except for one or two instances have not
seen high beetle numbers in the soybeans. A picture of the western corn rootworm
is available at http://ohioline.osu.edu/icm-fact/images/39.html.
Now is a good time to check lodged corn fields to see why the plants are lodging. The root system can be inspected by digging up the plants and carefully removing the soil from the root system by washing with water. This allows one to see if there is any feeding damage from rootworm larvae to the root system. Damage from rootworm larvae appear as either tunneling of the roots or feeding directly on the roots from the root tip toward the plant. If part of the lodging damage has been caused by rootworm we need to know that because it will result in different production practices in the future.
Root damage from rootworm can be rated using the Iowa 1 to 6 scale with 1 equal to no feeding damage and 6 equal to a severely damaged root system. The guidelines in the using the Iowa scale are:
1 = No feeding damage
2 = A few feeding scars present
3 = At least one root chewed to within 1-1/2 inches of the plant.
4 = One entire node of roots destroyed.
5 = Two entire nodes of roots destroyed.
6 = Three or more nodes of roots completely destroyed.
Five to 10 roots should be inspected in each field to get an idea of the amount of feeding damage that is being caused by the rootworm. Economic injury normally occurs when the rating is 3 or above.
This is also a good time to start checking soybeans for WCR beetles to see if the FYCR problem is going to be in a field in 2003. The best way to monitor a soybean field for WCR is the use of yellow Pherocon sticky traps. The traps are placed in the soybeans on metal posts and then changed every week or two and replaced with new traps. The number of WCR beetles are counted each time the traps are removed and these counts are used to make a decision about that field if it goes to corn in 2003. We have been monitoring soybean fields in Ohio with the yellow sticky traps since 1998. With help of OSU Extension agents, a number of soybeans fields are being monitored this year in northwest and west central Ohio. This area of the state is where we think the FYCR will occur first when it moves into the state. A few other counties in other parts of the state are also being monitored with yellow sticky traps. More information about using yellow sticky traps to monitor for WCR beetles can be found on the WEB at: http://ohioline.osu.edu/ent-fact/0017.html
Preliminary counts from 2002 already indicate that WCR beetle counts in soybeans in northwestern Ohio are higher this year than in previous years. The numbers vary considerably from field to field and that is why it is necessary that every field be checked. Checking one field on a farm or in an area and then using that field to make decisions about other fields on the farm or in the area is not possible.
If one cannot use the sticky traps to monitor soybeans then a second alternative is to visually inspect the fields by walking them for the next several weeks and making notes on the number of WCR beetles that are seen. The other method to sample for WCR beetles in soybean is to sweep the soybeans and record the number of beetles collected in the sweeps. The important thing this year is to use some method to check the soybean fields so that a decision about FYCR can be made on those soybean fields going to corn in 2003.
We listed chemicals in the newsletter last that can be used to control silk clipping beetles and failed to mention that Lorsban 4E is labeled on corn for silk clipping beetles.
The first generation of bean leaf beetle is now active in Ohio soybean fields. Most fields probably do not have a large population, although some fields, especially if early planted, might have larger numbers. Although defoliation from this beetle alone is usually not severe enough to warrant treatment, feeding from this and other defoliators such as Japanese beetle, grasshoppers, and green cloverworm can often reach levels requiring insecticide treatment. Growers should scout their fields to ensure that such levels, usually set around 15% defoliation during bloom and pod set, are not being reached. If defoliation reaches this level and insects are present and still actively feeding, treatment is probably warranted. Of special concern this year is that most soybeans are not that large, with smaller than normal canopies. Assuming the insects are feeding normally, the likelihood that economic levels of defoliation are reached sooner is greater.
Another reason to scout for the bean leaf beetle at this time concerns pod feeding by the second generation that occurs in mid-to-late August and September. That generation is the generation that can cause greater loss for growers because the insects feed directly on the pods and seeds. Research shows good correlation between the first generation and the second generation that will be present later. Thus, large bean leaf beetle populations at this time suggest a greater likelihood for a large second generation, and thus, a greater potential for significant pod injury. Thus, growers can help to identify fields over the next few weeks that have a higher potential for pod injury. This will allow growers to better manage their time and fields later in August. We will have more information in the newsletter next month on bean leaf beetle pod feeding.
Information on the 2002 Farm Bill and a Excel spreadsheet designed to help estimate program payments are available to view or download at: http://aede.osu.edu/programs/outlook/farm_bill/
Carl Zulauf, Barry Goodwin and Carl Norden of the Agricultural Environmental & Developmental Economics department have adapted an Excel spreadsheet for Ohio use that calculates total farm program payments under various base (contract) acreage and program (payment) yield updating options of the 2002 Farm Bill. Program payments estimated here include fixed payments and countercyclical payments which are decoupled from planting decisions. Keep in mind that this is merely a tool to aid program participation decisions and will not deal with all individual farm conditions, and as such can be of assist to individuals to evaluation their alternatives. Questions on farm program guidelines and regulations are best referred to FSA.
A taxpayer who has been reporting CCC loans as loans, may shift at any time to reporting CCC loans as income. The question is the procedure for shifting from reporting CCC loans as income to reporting such loans as loans in order to manage taxable income.
Before 2002, under the regulations, application for permission to change had to be filed within 90 days after the beginning of the taxable year to be covered by the return. IRS has established procedures for taxpayers to receive a 90-day extension of time for applying for a change in method of accounting under the regulations.
Effective for taxable years ending on or after December 31, 2001, IRS has ruled that a taxpayer reporting CCC loans as income can switch automatically to treating CCC loans as loans. For the year of change, all loans for all crops that year are reported as loans. Loans taken out previously continue to be treated as if the election to report loans as income was still in effect.
This change will give farmers more flexibility in managing taxable income for 2002. More details and procedures will be available later this year.
(Source: Article by Neal Harl, Iowa State University and edited by Robert D. Fleming, District Specialist, Farm Management, Northwest District.)
Don't for get Farm Focus '02 on August 6 & 7, 2002. This year's show includes: 300 acres of research plots, 45' narrated wagon tours, a 15 acres exhibit area with 150 exhibitors, and featured speakers. Times: Tuesday August 6th 8:00 am to 5:00 pm, and Wednesday, August 7th 8:00 am to 4:00 pm. Location is at the corner of U.S. 30 and U.S. 127 near Van Wert, Ohio. See the Farm Focus website at: http://www.farmfocusshow.com
Readers can subscribe electronically to this newsletter by sending an e-mail message to: corn-out-on@postoffice.ag.ohio-state.edu. A successful subscription message will receive by an automatic reply from the listserv. Contact your local Ohio State University Extension Office or e-mail labarge.1@osu.edu if you have problems subscribing.
Past versions of C.O.R.N. can be found on the World Wide Web at: http:/www.ag.ohio-state.edu/~corn/archive/
C.O.R.N. is a summary of crop observations, related information, and appropriate recommendations for Ohio Crop Producers and Industry. C.O.R.N. is produced by the Ohio State University Extension Agronomy Team, State Specialists at The Ohio State University and Ohio Agricultural Research and Development Center. C.O.R.N. Questions are directed to State Specialists, Extension Associates, and Agents associated with Ohio State University Extension and the Ohio Agricultural Research and Development Center at The Ohio State University.
State Specialists: Peter Thomison (Corn Production), Mark Loux & Jeff Stachler (Weed Science), and Bruce Eisley & Ron Hammond (IPM). District Agents: Robert Fleming (Northwest) Extension Agents: Steve Foster (Darke), Barry Ward (Champaign), Mark Koenig (Sandusky), Roger Bender (Shelby), Alan Sundermeier (Wood), and Dave Jones (Allen).Editor: Dave Jones Web Editor: Tom Rosati
Information presented above and where trade names are used, they are supplied with the understanding that no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.
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