http://www.ag.ohio-state.edu/~corn/ |
|
In This Issue:
A) Fall Control of Winter Annual Weeds in Wheat
B) Higher than Expected Test Weights in Corn
C) Genetically Modified Organisms: What Are They?
D) Should you sample your fields for Soybean Cyst Nematode?
E) November 15th and 16th Meeting Will Discuss Market Access and GMO's
F) Get the 1999-2000 Regional Agronomy Meetings on Your Calendar
A number of wheat fields have populations of winter annual weeds emerging, and you can expect winter annual emergence to continue into the fall as long as we have fairly warm weather. Options for control of winter annuals, which include common chickweed, henbit, mustards, field pennycress, and shepherdspurse, are fairly limited. Harmony Extra can be applied after wheat is in the 2-leaf stage - this is a change from previous labels which stated "in the spring after the 2-leaf stage". Harmony Extra is labeled for control of most winter annuals. Peak can be applied after the crop is in the 3-leaf stage, and also controls a number of winter annuals. However, Peak has the potential to carryover into soybeans grown after wheat, especially where soil pH approaches 7.8. Using Peak eliminates any chance of planting double-crop soybeans next summer.
Applying herbicide in the fall can be very effective for winter annual control, since most winter annuals emerge in the fall. Soil is often more suitable for traffic in the fall, and small weeds are more easily controlled. It can be difficult to get the right combinations of plant size, soil conditions, and weather that allow effective herbicide application in early spring. Where wheat has not yet been planted or emerged, Roundup, Touchdown, or Gramoxone can be used to control small winter annuals. Do not use 2,4-D or Banvel just prior to or immediately after wheat planting, as crop injury or stand reduction can occur.
Along with reports of better than expected grain yields in many drought stressed corn fields, I'm also hearing of higher than normal test weights in corn. Given that many fields received less than 8 inches of rain during the growing season, this has been good news but the high test weights (greater than 56 pounds per bushels) have also puzzled growers.
Test weight is a measure of the weight of a given volume of grain, specifically a volume bushel (32 quarts). The standard test weight most often used for corn is 56 pounds per bushel. The minimum acceptable test weight for U.S. No. 2 corn is 54 pounds per bushel. Test weight reflects the density of a sample of grain and is not necessarily related to grain yield (pounds per acre). Most studies indicate that corn feed value is affected very little by test weights in the 40-59 lbs/bu range.
Test weight and grain moisture are related to the extent that the wetter grain usually has lower test weight than drier grain. As grain dries (either in-field or artificially), its test weight usually increases several pounds per bushel. This year's high test weights may have been due in part to the exceptionally low grain moisture at harvest - I've heard reports of harvest grain moistures as low as 12% in mid September! One of the reasons that test weight increases as grain dries is that dry kernels pack together more easily, thus more kernels fill a volume bushel and test weight increases. Test weight also increases as grain dries because kernels shrink somewhat as moisture is removed allowing more kernels to fill a volume bushel.
Test weight is also influenced by the stresses that occur during the grain fill period. Factors that decrease the rate or duration of grain fill can result in lower than acceptable test weights at harvest. Severe drought, excessive soil moisture, nutrient deficiencies, persistent cloudy weather, European corn borer infestations of the stalk and ear shank, temperature extremes, leaf diseases, stalk rots, hail damage and frosts that injure or kill immature corn can all decrease test weight. Although corn was subjected to serious moisture stress and prolonged periods of high temperatures in 1999, disease and insect damage was generally negligible, and the corn crop matured well before frost. Moreover excessive soil moisture early in the season (which promotes nitrogen loss and retards early root development and growth), and cloudy weather were certainly not problems - in fact, warm, dry early season conditions probably promoted deeper root development and helped reduce the impact of moisture deficiency.
Although corn ears from stressed sites exhibited significant "tip-dieback" and reduced ear size, a reduced number of kernels per ear may have reduced some kernel competition and allowed better kernel fill for the reduced number of kernels present. In fields associated with good test weights, drought damage did not cause premature plant death, but there was extensive "cannibalization" in corn plants as the crop neared maturity, which may have helped reduce grain yield loss, as well as prolong grain fill.
Genetically Modified Organisms (GMOS) are plants, bacteria, fungi, or animals created using DNA (Deoxyribonucleicacid) recombinant techniques. A piece of DNA from one organism is inserted into the genetic code another organism to create GMOS. The word "transgenic" (genes from one organism into another) has also been used to describe a genetically modified organism.
Recall that DNA is composed of a nucleic acid base (4 different bases), a phosphate group and a ribose sugar. DNA in the form of base pairs can be combined in perhaps an infinite number of combinations to form genes which in turn are located on chromosomes. Additionally, different organisms may have different numbers of chromosomes.
The complete set of instructions for making an organism is called its genome. The human genome is thought to have 100,000 genes (best estimate) located on 23 chromosomes (haploid number). These 100,000 human genes are made up of 3 billion base pairs. Genes determine who we are; for example height, eye color, hair color and thousands of other traits.
Research is currently underway to identify and map the locations of genes not only for humans but in many other organisms (corn, soybeans, wheat, etc.) as well. Genes direct the growth and development of organisms. We have observed for example that some people as a result of their ‘good' genes are less susceptible to certain of life's ailments such as cancer, heart disease, diabetes, dental caries, myopia, and so forth. By identifying genes responsible for specific traits and using the fruits of the new recombinant DNA biotechnology, we may be able to prevent, mitigate or treat human disease, this is already beginning to occur.
One of first GMOS was a bacterium with a human gene inserted into its genetic code for the production of very high quality human insulin. Insulin has been produced using a GMO for about 15 years. Other examples of the use microbes, that are GMOS, to produce desirable medicines for man include: interferon for cancer, erythropoetin for anemia, growth hormone for treatment of dwarfism, tissue plasminogen activator for heart attack victims, and hepatitis B vaccine. And this is but the beginning.
Many other vaccines, cancer medicines and functional foods are in the pipeline presently. But GMOS are not just a part of medicine; they have become major constituents of agriculture (and many other industries). Flavr Saver tomatoes, Bt corn, cotton, and potatoes, and Roundup Ready soybeans and BST are a few examples of GMO's in agriculture.
We have entered the era of biotechnology, but so did people 6000 years ago. Biotechnology has as its root, words from the ancient Greek: bios which means life, technikos which means tool, and logos which means study of. Thus a translation is: the study of or use of living tools (organisms ) to run a process or create a product.
Biotechnology is not new. For example, the following are a few selected events in the history of biotechnology.
4000 BC, Egyptians used yeast in wine and bread making
3000 BC, Peruvians select and grow potatoes
2000 BC, Chinese develop fermentation
1861, Pasteur uses heat to kill bacteria
1865, Mendel develops principles of genetics
1879, Beal develops hybrid corn
1910, Morgan discovers genes on chromosomes
1928, Griffin discovers genetic transformations in bacteria
1941, Oswalt et al demonstrates the relationship of DNA to genes
1953, Watson and Crick describes the double helix structure of DNA
1970, Berg, Cohen and Boyer introduce recombinant DNA techniques
1982, human insulin is produced by a GMO
1990, Chymosin, an enzyme used in cheese-making is produced by a GMO
1993, BST (Posilac) produced by a GMO is introduced by Monsanto
1994, FlavrSavr tomato introduced
1995, Bt corn introduced
1996, Roundup Ready Soybeans introduced
In conclusion, modern recombinant DNA techniques used to create GMOS can be thought of as a more precise version of biotechnology methods employed throughout history. And, the use of new biotechnology will help agricultural professionals increase crop productivity and produce better foods.
If you are still on the fence as to whether to sample your fields or not, here are some questions to ask yourself:
1) Are your yields 5 bushels or more lower than your neighbors?
2) Have there been areas of the field where soybeans have turned yellow early?
3) Areas of the field in which Sudden Death Syndrome was diagnosed?
4) Has this field had soybeans cropped for more than 3 out of the last 5 years?
5) Have you had a positive SCN count in the past?
6) Do your fields have high numbers of winter annuals (additional host plants of SCN) -
purple deadnettle, shepards-purse and henbit?
7) Are there a number of fields in your county that are positive?
8) Could you have spread SCN to new fields with tillage/harvest equipment?
If you have answered yes to any of the above questions, sampling your fields should be a priority for this fall. The best news about testing this fall is that "It's Free!"
Testing Procedures: SCN management guidelines are based on an overall ESTIMATE of the nematode populations in your fields. It is very important to collect a sample that is representative of each field. SCN tends to occur in clumps in the field - so collect 10 to 20 soil cores in a zig-zag pattern across a 10 acre section of a field. Mix the soil thoroughly and submit a pint of soil to the:
C. Wayne Ellett Plant & Pest Diagnostic Clinic
Room 110, Kottman Hall
2021 Coffey Road
The Ohio State University
Columbus, OH 43210
Check the IPM-website or contact your local county extension agent for county reports, winter annual control methods and other questions pertaining to SCN - http://www.ag.ohio-state.edu/~ipm/scn/scn.htm.
There is another bulletin available to soybean producers that is excellent. Soybean Cyst Nematode Management Guide - available free of charge from the SCN Coalition, call 1-877-SCN TEST - (1-877-726-8378)
If you have questions about genetically modified organism (GMO) crops and market access, the November 15th and 16th Biotech Forum will provide answers. The Ohio Corn Growers Association and Ohio Soybean Association have set up a dialogue opportunity for farmers to talk with representatives of companies such as Monsanto, Pioneer, The Anderson's, Cargill, Iam's Dog Food, Wyandot Snack, Central Soya, Novartis and ADM. Some of the conference objectives are
1) Determine the current market status of genetically modified corn and soybeans.
2) Secure the U.S. position as a reliable supplier of corn and soybeans in the global
market.
3) Discuss technology transfer and risk allocation.
4) Evaluate worldwide approval of transgenic crops.
5) Discuss the future of new technologies.
The forum features panel discussions on three biotechnology impact areas Technology Input for Corn/Soybeans, Grain Merchandising/Export and Food/Food Ingredient issues. Forums will be held November 15, 1999 at Urbanski Catering, Findlay and November 16, 1999 at Der Dutchman Restraunt, Plain City. Both programs are scheduled from 8:30 a.m. until 2:00 p.m. Call the Ohio Corn Growers Association at 1-800-695-0483 or e-mail at ohiocorn@on-ramp.net for reservations or more details.
Seven regional Agronomy meeting will be presented in December and January. Below is a listing of dates and locations for these meetings. Complete agenda information for these 9:00 a.m. to 3:00 p.m. programs are available by contacting the hosting Extension office. A $15 registration is due 7 days prior to the meeting date, after that a $20 fee will be charged. Participants can get CCA and Pesticide Applicator credits.
Wednesday, December 8, Allen Co.
Reed Hall Auditorium,
OSU Lima Branch, Lima, OH
Host agent contact: Dave Jones
OSU Extension, Allen County
3900 Campus Drive, Suite B
Lima, OH 45804-3946
(419)222-9946
Thursday, December 9, Montgomery Co.
Arbor Hall, 2150 Arbor Blvd., Dayton
Host agent contact: Steve Bartels
OSU Extension, Butler County
1810 Princeton Road
Hamilton, OH 45011-4797
(513)887-3722
Friday, December 10, Champaign Co.
Champaign Co. Community Center
1512 S. US Highway 68, Urbana
Host agent contacts:
Barry Ward & Larry Bracket
OSU Extension, Champaign County
1512 S. US Highway 68, Suite B100
Urbana, OH 43078
(937)652-2204
Monday, January 17, Licking Co.
Licking Co. Joint Vocational School
150 Price Road, Newark
Host agent contact: Howard Siegrist
OSU Extension, Licking County
771 E. Main St. Suite 103
Newark, OH 43055-6974
(740)349-6900
Tuesday, January 18, Clinton Co.
Expo Center, Clinton Co. Fairgrounds,
Intersection of Main and Nelson, Wilmington
Host agent contact: Tony Nye
OSU Extension, Clinton County
111 S. Nelson Avenue, Suite 2
Wilmington, OH 45177-2099
(937)382-0901
Wednesday, January 19, Seneca Co.
Camden Falls Conference Center,
2460 S St. Rt. 231
(1/8 mi. N of US 224), Tiffin
Host agent contact: Clark Hutson
OSU Extension, Seneca County
155 ½ E. Perry Street
Tiffin, OH 44883-2389
(419)447-9722
Wednesday, January 19, Richland Co.
John Hartz Activity Bldg. & Youth Hall,
Richland Co. Fairgrounds,
750 N. Home Road, Mansfield, OH
Host agent contact: Maurus Brown
OSU Extension, Richland County
1495 W. Longview Ave., Suite 206
Mansfield, OH 44906
(419)747-8755
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
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.
Contributors to C.O.R.N. this week include: State Specialists: Anne Dorrance and Pat Lipps (Plant Pathology), Mark Loux (Weed Science) and Peter Thomison (Corn Production); District Specialist: Ed Lentz (Agronomy); Extension Agents: Barry Ward (Champaign), Steve Prochaska (Crawford), Larry Lotz (Fayette), Greg La Barge (Fulton), Gary Wilson (Hancock), Ray Wells (Ross), Clark Hutson (Seneca), Roger Bender (Shelby).
Editor: Clark Hutson Web Editor: Nathan Watermeier
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.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.
TDD # 1 (800) 589-8292 (Ohio only) or (614) 292-1868
| C.O.R.N. | Newsletter | Archive | Search | Questions? | Ohioline | Publications |