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Agnet April 26/04 -- II
Ontario College of Family Physicians alarms public unnecessarily
Council fails to reach majority in favour of biotech sweet corn despite new traceability and labelling rules
GM cotton boosts profits for African farmers
Altered corn ignites furor in Mexico
Despite ban, agriculturists can't stop farmers from planting Bt corn
Biotech advantages spurring rapid adoption
Don’t neglect alfalfa fields
Insects feeding on early emerging corn
Cool, wet soils increase risk of damping off
Folicur: a new tool for managing fusarium head blight in wheat
Cereal leaf beetles are active in small grains
Dry topsoil concerns some corn growers
Micro-rate herbicide applications underway in 2004
Insect resistance management learning center
Producers encouraged to scout seedling corn
Plant full-season corn hybrids first
Reminders on preplant burndown herbicide applications
What should be planted first - Soybeans or corn?
Simple, low-cost way to boost canola yields 10-20%
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Ontario College of Family Physicians alarms public unnecessarily
April 26, 2004
From a news release
TORONTO - Pesticides can be safely used to control pests in agricultural, home and garden settings despite the recent announcement by the Ontario College of Family Physicians (OCFP), according to CropLife Canada. Health Canada's Pest Management Regulatory Agency registers all pest control products used in Canada. No product can be used in Canada if it causes any unacceptable health risk including cancer. This internationally recognized regulatory process entails extensive scientific review and evaluation of all available studies, including those that may identify potential health risks.
"Studies, such as in the literature review done by OCFP, will have already been taken into account by Canada's pesticide regulators. These epidemiological studies do not establish that pesticides cause any health problems. The public is not well served by OCFP drawing conclusions about the safety of pesticides based only on selective and incomplete studies," says Lorne Hepworth, President of CropLife Canada. "Press conferences and sensational comments, in this case, only serve to alarm the public unnecessarily. Public education on the safe and responsible use of pesticides using integrated pest management is the answer, not fearmongering," adds Hepworth.
When regulating pesticides, Health Canada ensures that stringent safeguards are in place for human health, including infants and children.
Council fails to reach majority in favour of biotech sweet corn despite new traceability and labelling rules
April 26, 2004
EuropaBio
http://www.europabio.org
Today, the Agriculture Council of Ministers failed to reach a qualified majority vote to approve a genetically modified sweet corn (Bt-11) for food use in the European Union; it is already approved in other parts of the world.
Johan Vanhemelrijck, Secretary General of EuropaBio (European association for bioindustries) is cited as saying: "We are disappointed that the Council failed to approve the sweet corn but now look to the EU Commission to move forward with a decision to approve this product. The file was submitted in 1998 and the EU Scientific Committee on Food has declared Bt-11 as safe as its conventional counterparts."
In 1998, some Member States said they would not approve any new products until new laws on traceability and labelling were in place. These rules came into force in the EU on 18th April. "We are disappointed that some Member States have not kept their side of the agreement despite the fact that all the conditions have been met," says Johan Vanhemelrijck.
The GM sweet corn is approved for food use in Argentina, Australia, Canada, China, Japan, Korea, New Zealand, the Philippines, Russia, South Africa, Switzerland and the United States and was first approved in United States and Canada in 1996.
The application will now be passed back to the EU Commission which is expected to approve it.
GM cotton boosts profits for African farmers
April 26, 2004
SciDev.Net
Christina Scott
http://www.scidev.net/news/index.cfm?fuseaction=readnews&itemid=1339&language=1
CAPE TOWN-- A South African study of cotton grown by more than 2,000 farmers showed that those that planted Bt cotton — which has been genetically engineered to resist the bollworm pest — benefited by US$86 to US$93 per hectare more than those that planted conventional strains.
The study, conducted by a team of scientists from Reading University, United Kingdom is the first time that Bt cotton in Africa has been assessed on the basis of farmers' own practice, rather than on the results of controlled field trials. The results could be significant for Africa's agricultural economy: cotton is grown on 2.5 million hectares of the continent, most of it on small plots of less than 10 hectares.
Writing in this month's Nature Biotechnology, the researchers were cited as saying that Bt cotton gave better yields in each of the three seasons studied, and that the results were particularly striking "in the poor, wet growing season of 1999-2000, which favoured the bollworm".
Although Bt cotton seeds are more expensive than conventional ones, the research in Nature Biotechnology indicates that this is more than compensated for by lower pesticide costs, both in terms of buying the product and the cost of hiring labour to apply it.
Altered corn ignites furor in Mexico
April 25, 2004
Chicago Tribune via Checkbiotech
Hugh Dellios
http://www.checkbiotech.org/root/index.cfm?fuseaction=news&doc_id=7643&start=1&control=200&page_start=1&page_nr=101&pg=1
CAPULALPAN, Mexico -- Mexico's recent confirmation that American-manufactured, laboratory-modified genes have somehow appeared in cornfields in Mexico's remote hills has fueled an impassioned debate over "transgenic" products and their potential impact on human health, the environment and the survival of Mexico's traditional corn varieties.
The government announcement in February gave credence to claims by a team of California scientists that they found lab-created genes in corn in Oaxaca three years ago. But it did not solve the mystery of how the genes got there despite a 5-year-old ban on planting transgenic crops in Mexico.
The findings have led environmentalists and others to call for a moratorium on Mexico's annual imports of more than 5 million tons of cheap feed corn from the U.S. Those imports have been important for farmers in Illinois and Iowa while helping Mexico introduce more chicken, eggs and other protein into the national diet.
In the next few weeks, the Commission for Environmental Cooperation, an international watchdog agency created in the wake of the North American Free Trade Agreement, will complete the first comprehensive study of the potential impact of modified genes on Mexican corn. Its findings will be presented in June with recommendations on how to proceed.
Despite ban, agriculturists can't stop farmers from planting Bt corn
April 23, 2004
MindaNews
Allen Estabillo
http://www.mindanews.com/2004/04/23nws-btcorn.html
KORONADAL CITY -- Reynaldo Legaste, provincial agriculturist in South Cotabato was cited as saying that they can't stop farmers from planting the controversial Bacillus Thuringiensis (Bt) corn in the province despite an earlier moratorium declared by the provincial government.
The national government approved of the genetically engineered crop's commercialization in the country in late 2002.
Two years ago, the Sangguniang Panlalawigan passed a resolution banning further testing and planting of Bt corn in the province due to supposed health and environmental risks.
The ban came after a series of protests against the field tests in the province conducted by its proponent Monsanto Philippines.
The ban, which was eventually upheld by South Cotabato Gov. Daisy Avance-Fuentes, came after the Koronadal city council declared the area GMO-free.
"But the resolution was just an expression of (the SPs) sentiments, nothing more," Legaste insisted.
Lawyer Ely Pastores, SP secretary, said the resolution banning the planting of Bt corn is a form of local legislation and must be strictly implemented.
However, he also admitted that the resolution could not provide tangible actions on those who would continue to plant Bt corn since it has no penalty clause, a provision present only in ordinances.
Biotech advantages spurring rapid adoption
Apr 23, 2004
Delta Farm Press
Hembree Brandon
http://deltafarmpress.com/news/hembree-column/
Greg Lamp, editor of Corn and Soybean Digest is cited in this article as saying that U.S. farmers will have to utilize GE technologies in order to stay competitive in world markets, explaining that: “Farmers in South America, with cheaper land and labor, are nipping at our heels. We’ve got to stay on top of these new technologies or they’ll will pass us.”
Forrest Laws, executive editor for Farm Press Publications, says that farmers have moved to GE varieties “because it helps to simplify their lives. These seed may cost more than conventional varieties, but they allow producers to get more done more efficiently.”
At the same time they’re moving enthusiastically into new technologies, Laws says, farmers have been active in adopting production measures that will help keep older, effective materials on the market. “Agriculture has done a good job of lobbying the Environmental Protection Agency and other federal agencies to keep useful products available.”
Karen McMahon, editor of Farm Industry News Biotechnology, says that biotechnology “has revolutionized the seed industry.” Future seeds, she says, may contain genetic codes that will allow them to tolerate wide variations in environment, “perhaps allowing a farmer to plant a crop at any time during the year, with the seed programmed to germinate when the proper conditions occur.”
Dale Miller, editor of National Hog Farmer, says several projects are under way in the animal sector to identify genes for disease resistance, so producers could better control costly diseases in their herds and reduce the potential for antibiotic resistance. Scientists are also looking for ways to manipulate genes to reduce stress in animals and increase production efficiency.
Primediabusiness Chief Executive Officer Martin Maleska says the developments in biotechnology only skim the surface of the revolution that is occurring in information. “
Don’t neglect alfalfa fields
April 23, 2004
Purdue Pest Crop Newsletter No.6
John Obermeyer and Larry Bledsoe
http://www.entm.purdue.edu/Entomology/ext/targets/newslett.htm
Scout alfalfa NOW for weevil damage!!! • Warm temperatures have accelerated larval development and activity. • Use highest rate of labeled insecticide for longest possible residual control. • If a second application is necessary, adhere to product rate and harvest restrictions. Alfalfa fields in southern and central Indiana need to be inspected immediately for weevil tip feeding and skeletonization of leaves. Three southern Indiana Purdue Agricultural Centers have reported 12, 32, and 87% tip feedingthispastweekinfieldsbeingregularlymonitored (thanks to Don Biehle, Richard Huntrolds, and Frankie Lam). Betsy Smith, Grower’s Co-op, out of Terre Haute informed us that 8 out of 10 fields being scouted in her area have reached the treatment threshold.
Last fall and winter’s relatively mild temperatures have allowed for successful egg and adult over-wintering. The high variability in numbers and size of larvae seen this spring, also indicate that egg laying occurred over an extended period, and that larvae will be present longer than normal. Unfortunately, unless beneficial organisms (both parasitic wasps and pathogenic fungi) begin to really kick into gear, some fields may need to be treated more than once. Should this be the case, be certain to adhere to rate-use and pre- harvest restrictions. Management guidelines for southern Indiana suggest that fields be treated when there are 3 or more larvae per stem and tip feeding is at least about 50%. Most insecticide labels suggest using higher rates for increased residual control.
Insects feeding on early emerging corn
April 23, 2004
The Bulletin No. 5
University of Illionois
http://www.ipm.uiuc.edu/bulletin/article.php?issueNumber=5&issueYear=2004&articleNumber=14
According to this report, the forecast for flea beetles and Stewart's wilt in 2004 ranged from moderate to severe in southern and western counties.
Early reports indicate that flea beetle infestations are fairly heavy in some of the earliest planted cornfields in Adams and Pike counties in Western Illinois, with an average of 3 to 4 beetles per plant, in some fields in the Mississippi River bottoms (where the earliest emerging corn in his area is located). Feeding injury was significant in some areas of some fields.
An infestation of southern corn leaf beetles has also been reported in a field in Adams County that was planted on March 23. The seedlings in the field are 3 to 4 inches tall (one collar), and the beetles are cutting through the small stems as they feed. The injury was severe enough that an insecticide application is warranted.
Corn producers and agricultural advisors should check early emerging cornfields for the presence of flea beetles, southern corn leaf beetles, and other early-season insects, as well as signs of their feeding injury. The corn flea beetle is a small (~1/16 inch long), oval, shiny black beetle with enlarge hind legs that enable them to jump when disturbed. The southern corn leaf beetle also is small (~3/16 inch long), and is dark brown, often covered with bits of soil. The prothoracic shield just behind the head has three "teeth" on each lateral edge.
Flea beetles injure corn by feeding of the epidermis of leaves, resulting in small feeding streaks or windowpane feeding patches.The other concern with flea beetles is the potential for their vectoring the bacterium that causes Stewart's wilt.
Southern corn leaf beetle adults feed on the stems and chew out notches on the edges of leaves of corn seedlings; injured plants appear ragged. Occasionally the adults occur in such large numbers that injured plants die, especially if the beetles chew through the stems.
Treatment for corn flea beetles on seedling corn may be warranted if you find 5 or more beetles per plant before the V5 stage of growth, especially if the plants are suffering from environmental stress.
Treatment for southern corn leaf beetles may be warranted if enough corn seedlings are being killed that the plant population could be reduced significantly. There currently are no thresholds based upon numbers of southern corn leaf beetles or extent of injury. Again, environmental stresses (including cool temperatures the slow corn growth) will play a role in treatment decisions.
Cool, wet soils increase risk of damping off
April 22, 2004
Kentucky Pest News
University of Kentucky
Paul Vincelli
http://www.uky.edu/Agriculture/kpn/kpn_04/pi040419.htm
In most of the Commonwealth, soils were wet with temperatures in the high 40's to lower 50's F For most or all of the period of April 11-16. These conditions are very favorable for development of infections of corn seedlings by the soilborne organism Pythium ultimum, the most common cause of seed rots and seedling damping of field corn in Kentucky. P. ultimum thrives in saturated soils. While it actually prefers warmer soils, soil temperatures in the range of 48-53 F severely curtail the ability of the corn seedling to defend itself against infection. Thus, a period of cool wet soil conditions like we had last week can favor stand loss from P. ultimum, particularly if the corn seed is of low vigor or the crop is under stress for some other reason.
Since corn yields are strongly influenced by plant population, it would be advisable for producers to scout fields for plant populations 2-4 weeks after emergence.
Folicur: a new tool for managing fusarium head blight in wheat
April 22, 2004
Kentucky Pest News
University of Kentucky
Don Hershman
http://www.uky.edu/Agriculture/kpn/kpn_04/pn040419.htm#corpos
Fusarium head blight (FHB) of wheat, and deoxynivalenol (DON) accumulation in harvested grain, are periodically very serious problems in Kentucky. On April 15, 2004, the Environmental Protection Agency approved Kentucky's Section 18 application which sought emergency labeling for Folicur 3.6F to help with FHB/DON management during 2004. Folicur is manufactured by Bayer CropScience. This new fungicide tool, when used with other FHB/DON management tactics (see http://www.ca.uky.edu/ukrec/newsltrs/news03-2.pdf), will reduce the risk of FHB and DON, as long as weather conditions are not highly favorable to FHB and DON during crop flowering and grain fill.
Research suggests that about 30% reduction in FHB symptoms and DON accumulation is a reasonable expectation for winter wheat. Sixty percent control or more has been achieved in rare field studies in the United States, but these are atypical results.
The Section 18 allows for a single ground or aerial application of 4 fl oz/A of Folicur 3.6 F to wheat at full head emergence (Feeke's stage 10.5) to very early flowering (Feeke's stage 10.51). Applications cannot be made before full heading nor within 30 days of harvest. The Folicur Section 18 applies only to wheat and is good for the period April 20, 2004 to May 20, 2004.
Excellent fungicide coverage on wheat heads is crucial to achieve the greatest possible FHB/DON suppression. Discipline must be exercised to ensure that proper sprayer pressure and volumes are used.
For ground application, research has shown that best head coverage is achieved with a double-swivel nozzle configuration of XR8001 flat-fan nozzles oriented forward and backward at a 45 degree angle. Acceptable coverage can also be achieved with a single nozzle configuration using TwinJet TJ8002 nozzles. When using either the double-swivel nozzle or the single TwinJet configuration, best head coverage is achieved when the boom is set 8 to10 inches above the heads, spray pressure is 30 to 40 psi OR 80 to 90 psi, fungicides are delivered in 15 or more gallons or water/A, and ground speed does not exceed 8 mph during application.
For aerial application, nozzles should be angled to direct spray 90 degrees to the direction of travel. Spray droplet size should range from 300 to 400 microns and Folicur should be delivered in no less than 5 gallons of water/A. It is best to spray early in the morning or at other times when heavy dew is present. This will facilitate fungicide coverage on heads.
Regardless of the method of application, be sure to tank mix the lowest rate of a spray surfactant with Folicur to enhance coverage and optimize treatment effectiveness.
Cereal leaf beetles are active in small grains
April 22, 2004
Kentucky Pest News
University of Kentucky
Doug Johnson
http://www.uky.edu/Agriculture/kpn/kpn_04/pn040419.htm#corpos
Cereal leaf beetle (CLB) larvae are out and active. I have only seen adults (emerging from over-wintering) and eggs to date; very little feeding damage was evident. In general these insects do little damage but can be quite a problem, especially if they feed extensively on the Flag and F1 leaves.
The yellow football-shaped eggs usually are found in small groups (2-10 or so). They are attached to the plant tissue with one of the pointy ends. The adults that you might see are the over-wintering survivors and will disappear as egg laying proceeds.
The next stage to appear, and overlapping in time with the eggs, is the larval (juvenile) stage. They look like tiny slugs, are shiny and may be yellow to dark in color. As they increase in size they will begin to glue pieces of leaf material and other trash on their backs as a form of camouflage. They are often described as looking like bird droppings.
As we move through the season adults will appear again. You may see them in mixed populations with the larvae. Adults are 1/2" long shiny black beetles with a red area behind the head and red legs. The adults and larvae do the same type damage.
Damage symptoms are very diagnostic. They eat out the upper surface tissue between leaf veins, leaving the lower surface intact. This feeding produces parallel white streaks in the leaf. The damage is easier to see than the insects. However, the object should be to find the insect before finding many of these white streaks. Especially not many streaks on the Flag and F1 leaves! Feeding on lower leaves is of little interest.
Scout for these insects by examining ten randomly chosen tillers, in ten different locations in the field. This will producer a total of 100 tillers examined. Check all the leaves and stems for cereal leaf beetle eggs, grubs and adults. Note the number of tillers infested the number CLB eggs and the number of CLB grubs and adults. You will need to know if egg hatch is in the early stages or about finished. If you do not find any eggs or if eggs represent less than 50% of the CLB you find, then you don=t need to count again. If however, eggs represent more than 50% of the CLB you find, then you need to sample again in five to seven days. This insect will only have one generation that is important to wheat.
Your wheat will be most susceptible to this insect between Feekes Growth stages 8 and 10.1. The flag and F1 leaves are what need to be protected.
If you are producing very high value wheat (either very high yielding or high quality or wheat carrying a specific trait) you should consider control if on average you find one CLB larva or adult for every four tillers. This threshold is based on work done in North Carolina and Virginia. They generally have a better maturing season then we do, so the threshold is very conservative for Kentucky. Less quality wheat can tolerate higher numbers of CLB, probably closer to 1 CLB per tiller.
Dry topsoil concerns some corn growers
April 23, 2004
Purdue Pest Crop Newsletter No.6
Bob Nielsen
http://www.entm.purdue.edu/Entomology/ext/targets/newslett.htm
Corn planting in the Hoosier Boilermaker state is off to the races with 15% of the state’s crop acreage already in the ground, well ahead of the five-year average of 5% (Indiana Ag. Stats. Service, 4/19/04) and ahead of the previous record pace (8%) set in 1976. Reasons for the early rapid rate of corn planting include dry soils, warm soil temperatures (relative to early April), and short- term memories of last year’s wet May that delayed some corn planting until early June.
As of 18 April, 31% of the state’s topsoil moisture was rated as short to very short (Indiana Ag. Stats Service). One of the concerns when surface soils are dry is the increased risk of injury to corn germination or to young corn seedlings from pre-plant anhydrous ammonia applications. Such injury is caused by desiccation of belowground plant parts that come into contact with the ammonia zone. Symptoms of anhydrous injury include poor or weak germination, discolored kernels, wilted seedlings, and brown stubbed-off roots. Shallow injection depths (less than 7 – 8 inches), coarse-textured soils, and dry surface soils (especially cloddy soils) all increase the risk of ammonia movement farther than normal from the point of injection and thus the risk of injury to corn germination and young corn seedlings. Another concern related to dry surface soils is whether soil moisture at the seed zone is uniformly adequate for germination. Uneven soil moisture in the seed zone is the primary cause of uneven emergence, the results of can easily reduce yield potential by 6 to 9 percent. The key factor when faced with dry surface soils is taking the time during planting to visually inspect the soil moisture levels at the seed zone and change planter depth settings accordingly to best ensure placement of seeds into a uniformly moist seedbed.
Micro-rate herbicide applications underway in 2004
April 22, 2004
Michigan State University
Field Crop Advisory Team Alert Vol. 19, No. 2
Christy Sprague
http://www.ipm.msu.edu/CAT04_fld/FC04-22-04.htm#5
Crop Soil Sciences
Warm spring weather and the recent rains have given sugar beets and weed seedlings a jump in emergence compared to the last several years. This early emergence starts the beginning of micro-rate herbicide applications. Timing these applications is critical in providing good weed control and reducing sugar beet injury. Over the last couple of years, several growers have moved to timing micro-rate herbicide applications based on growing degree days (GDD). From recent surveys, approximately 45 percent of Michigan growers using micro-rates for weed control are tracking GDD. A majority of these growers are basing their micro-rate timings on 225 GDD (base 34°F) while others are using other variations between 200 and 250 GDD depending on weed populations and soil types. By timing their micro-rate applications using GDD, many of these growers have been able to maintain good weed control, reduce sugar beet injury, and reduce the number of micro-rate trips across the field equating to reduced weed control costs.
General recommendations for GDD micro-rate applications
The first micro-rate application should be made when weeds are less than 1/8-inch tall. Normally, this occurs around 275 GDD with early emerging weed species like common lambsquarters; however this year we have noticed earlier common lambsquarters and velvetleaf emergence with the warmer temperatures, and in some cases, have had common lambsquarters ready to treat at 200 GDD. Therefore, it is important to start scouting for the first micro-rate application earlier this season.
For the remainder of the micro-rate applications, research from MSU has shown applying micro-rates on a 225 GDD schedule has shown the most consistent weed control across species while reducing the potential for sugar beet injury. However, in fields with sandy or darker soils (high organic matter) and high weed pressures it is suggested to check fields at 150 GDD and time applications for 175 GDD. For growers who want to adjust the timing of micro-rates relative to weed emergence it may be possible to lengthen the spray interval early in the season (April) to 275 GDD when common lambsquarters is the predominant weed. In May, this interval should be shortened to 225 GDD until pigweeds (redroot pigweed and Powell amaranth) start to emerge, then micro-rate applications should be made every 175 to 200 GDD.
Insect resistance management learning center
April 23, 2004
The Bulletin No. 5
University of Illinois
Kevin Steffey
http://www.ipm.uiuc.edu/bulletin/article.php?issueNumber=5&issueYear=2004&articleNumber=3
The National Corn Growers Association, working with several land-grant university and industry entomologists, has launched the Insect Resistance Management Learning Center on their Web site at http://ncga.com/biotechnology/IRMCenter/index.htm. This Web-based tool addresses the need for standardized, comprehensive training on the principles of insect resistance management. The training focuses on insect resistance management, compliance assurance program, integrated pest management, corn borers, and corn rootworms.
The Insect Resistance Management Learning Center includes voice-over instruction, slides, and some animation, and users occasionally get an opportunity to answer questions. Accessing the lessons requires Acrobat Reader 5.0 or higher, Windows Media Player 6.0 or higher, and Macromedia Flash Player 6 or higher.
Producers encouraged to scout seedling corn
April 23, 2004
Integrated Pest Crop Management Newsletter Vol. 14, No. 6
University of Missouri-Columbia
Wayne Bailey
http://ipm.missouri.edu/ipcm/archives/v14n6/ipmltr6.htm
Each year, several different insect pests have the potential to cause significant damage to seedling corn. Recent changes in insect management options have moved from scouting and treating an insect pest once economic threshold levels have been reached to greater use of preventative or prophylactic insecticide applications prior to the development of a pest problem.
As with all insecticides, many factors can influence the ability of a specific insecticide to effectively control a specific pest species. Some of the more important factors influencing insecticide efficacy include: (1) the specific insecticide, rate and application method being used, (2) the species and size of insect pest being targeted, (3) the level of insect pressure on the crop, (4) the growth stage of corn plants when attacked by insects and (5) field growing conditions.
Regardless of the type of preventative insecticide application used (seed, liquid, granular or transgenic), producers are encouraged to scout crop fields throughout the season, but especially from emergence through the seedling stages of plant growth, the period when many insect pests are present.
Plant full-season corn hybrids first
April 20, 2004
C.O.R.N Newsletter
Ohio State University
Peter Thomison
http://corn.osu.edu/index.php?setissueID=33
Plant full-season hybrids first, then alternately plant early-season and mid-season hybrids, to take full advantage of maturity ranges and to give the later-maturing hybrids the benefit of maximum heat-unit accumulation. Full-season hybrids generally show greater yield reduction when planting is delayed compared with short- to mid-season hybrids. In areas with longer growing seasons, consider planting some acreage to early hybrids to have new corn for the early market (which usually commands a premium price and thus partially offsets the income effect of the lower yield associated with early hybrids). Planting early hybrids first, followed by mid-season, and lastly the full-season hybrids spreads the pollination interval for all the corn acres over a longer time period and may be a good strategy for some drought-prone areas.
Reminders on preplant burndown herbicide applications
April 20, 2004
C.O.R.N Newsletter
Ohio State University
Mark Loux
http://corn.osu.edu/index.php?setissueID=33
As a result of weed shifts and herbicide resistance issues that have developed over the past several years, use of the appropriate timing and selection of herbicides in no-till burndown treatments is more important than ever. Our assessment of these shifts in weed populations is that many have been caused by changes in herbicide programs, and more specifically, by the delay of burndown treatments from April into May (or elimination of burndown treatments in Roundup Ready soybeans), and the failure to include 2,4-D or other herbicides that are more effective than glyphosate alone on certain weeds. We have observed glyphosate-resistant marestail primarily in Roundup Ready soybean fields where glyphosate was the only herbicide used in the year of soybean production, and we assume that the inclusion of 2,4-D ester has helped delay resistance in many other fields. At this time, winter annual weeds are somewhat ahead of previous years in their development, and will require earlier treatment to prevent seed production and future increases in population density. Marestail in southern Ohio has started to bolt (stem elongation), and this weed is generally most easily controlled before stems exceed several inches in height. Some other reminders on herbicide treatments for burndown in no-till fields:
1. We strongly suggest including 2,4-D ester with glyphosate in all burndown treatments applied at least 7 days before planting, and including 2,4-D ester should be considered essentially mandatory in fields with marestail and dandelion. 2,4-D ester can be applied at a rate of 0.5 lb ae/A up to 7 days before soybean planting. When applied at least 15 days before soybean planting, several 2,4-D products (E-99 and Weedone 650) are labeled at the rate of 1.0 lb ae/A. The higher rate can be helpful on dandelion, larger marestail and giant ragweed, and dock species, among other weeds.
2. In soybeans, the addition of CanopyXL to glyphosate or glyphosate/2,4-D can improve control of a number of weeds, including dandelion, marestail, giant ragweed, prickly lettuce, and a number of winter annuals. The combination of CanopyXL plus glyphosate plus 2,4-D ester has been the most effective spring treatment for dandelion control, and the combination of glyphosate plus CanopyXL has been the most effective treatment on this weed where lack of time until planting precludes the use of 2,4-D ester. Including FirstRate/Amplify with glyphosate or glyphosate/2,4-D will improve control of marestail and giant ragweed. However, CanopyXL and FirstRate/Amplify will not improve control of emerged ALS-resistant marestail or ragweeds.
3. Most preplant soybean herbicides other than CanopyXL and FirstRate/Amplify do not contribute much to burndown activity. One exception is Sencor, which has effective activity on small, emerged weeds in combination with 2,4-D ester or 2,4-D ester plus Gramoxone. The combination of Sencor plus Gramoxone plus 2,4-D ester is effective for control of glyphosate- or ALS-resistant marestail up to a height of about 4 inches. Python also helps control small annual broadleaf weeds in mixtures with 2,4-D and/or glyphosate, but is generally less effective than CanopyXL. Several other herbicides, including Valor and Aim, may result in more rapid development of symptoms, but rarely improve control in combinations with glyphosate and 2,4-D ester.
4. Glyphosate containing treatments should be applied with ammonium sulfate or a similar product, and with nonionic surfactant where required by the label. Glyphosate activity can be reduced when applied in 28% or similar fertilizer solutions, especially on perennial or larger annual weeds. Treatments that do not contain glyphosate should generally be applied with crop oil concentrate, and the addition of low rates of 28% can improve control.
5. In corn, effective burndown options include Lumax, FieldMaster, Expert, or other combinations of glyphosate with preemergence residual herbicides. 2,4-D ester can be added to improve control of certain weeds, but treatments containing 2,4-D ester should be applied a week or so before corn planting where possible to reduce risk of corn injury. In OSU research in 2003, Lumax and Lumax plus 2,4-D were the most effective dandelion treatments, followed by mixtures of 2,4-D plus glyphosate plus residual herbicides.
What should be planted first - Soybeans or corn?
April 20, 2004
C.O.R.N Newsletter
Ohio State University
Steve Prochaska
http://corn.osu.edu/index.php?setissueID=33
Farmers today are planting corn and soybeans much earlier than farmers of 20 years ago. And this opportunity, when occurs, to pant early into dry soils may be beneficial because the growing season is extended and soils are not compacted. However, there are risks to planting very early and these risks will vary by crop. What follows below is risk/benefit analysis to early corn and /or soybean planting.
Soybeans - Benefits To Early Planting Soybeans (only when soils are dry!)
1. Extended growing seasons with high quality sunlight (more photosynthesis possible). The maximum amount of sunlight occurs in the months of May, June and July in Ohio.
2. Adequate moisture for crop development.
3. Perhaps the best seedbed of year and thus no soil compaction.
4. Spreading of work load (both fall and spring)
5. Newer seed treatments such as Apron, Maxim and Rival can help protect soybeans from certain plant pathogens during time periods unfavorable for growth.
6. Weed control costs may be reduced due to earlier canopy.
7. Opportunity to plant wheat in a timely fashion in September.
8. Time to evaluate and make a mitigating response in the event of a poor soybean stand.
9. Soybeans have the ability to flex over different environmental conditions, weather extremes and planting dates, and still yield well.
10. No loss of primary nutrients (P2O5 and K2O) applied in event of crop failures.
11. Most favorable temperatures for crop growth and development may occur from April 15 to July 15, as opposed to July 15 to September 1 (more carbohydrate deposition).
12. Opportunity to grow and harvest high yield soybeans (yields greater than 60 bushels/acre). Later planting may not allow such an opportunity due to loss of growing season.
Corn - Benefits to Early Planting (only when soils are dry!)
1. Extended growing season with high quality sunlight (more photosynthesis possible). The maximum amount of sunlight occurs in the months of May, June and July in Ohio.
2. Adequate moisture for early crop development.
3. Favorable temperatures for crop growth and development and thus carbohydrate deposition. Pollination may also occur during a period of cooler temperatures.
4. Perhaps the best seedbed of year and thus no soil compaction.
5. Spreading out of the work load (both spring and fall).
6. Newer seed treatments such as Apron and Maxim can help to protect (for relatively short periods of time) corn from certain diseases favored by adverse weather and soil environments.
7. Reduced weed control costs possible due to earlier canopy.
8. Can withstand a frost as long as growing points below ground.
9.Opportunity to grow and harvest very high yielding corn.
10. Longer growing season and thus the opportunity to have dryer corn at harvest.
Risks to Early Planted Soybeans
1. Hard freeze after soybeans are up (soybeans may withstand temperatures to about 26 degrees F for a short time) may kill plants.
2. Poor emergence due to extended periods or wet, cold weather (>25 days). More exposure to plant injuring insects and diseases.
3. Cost of replanting in the event of stand failure.
4. Lack of time to replant on a timely basis.
5. Additional weed control costs due to lack of early crop canopy.
6. Loss of yield due to loss of growing season in the event the initial planting fails.
Risks to Early Planted Corn
1. One chance to get good stand!
2. Poor emergence due to extended periods or wet, cold weather. More exposure to plant injuring insects and diseases.
3. Cost of replanting in the event of failure.
4. Lack of time to replant on a timely basis.
5. Additional weed control costs due to lack of early crop canopy.
6. Loss of yield due to loss of growing season in the event the initial planting fails.
7. Potential loss of applied preplant nitrogen via leaching or denitrification.
8. Corn herbicides may preclude planting soybeans in the event of corn stand failure.
Simple, low-cost way to boost canola yields 10-20%
April 26, 2004
Canola Council of Canada Press Release
Looking for a sure fire, low-cost way to boost canola yields by 10 to 20% this year? Simple. Avoid planting canola on last year's canola stubble, says
Derwyn Hammond, Agronomist, Manitoba for the Canola Council of Canada. Stick with a one-in-four rotation for long-term success, he adds. "Research trials and crop insurance data show canola yields are higher following cereals, flax or a pulse crop than following canola, often by as much as 10 to 20% or more. Each of these crops in turn also fairs better when seeded into canola stubble, with the exception of flax which can suffer from phosphorous (P) deficiency due to reduced levels of vesicular-arbuscular mycorrhizae--the fungi which aid in making soil P available to plants," he says.
Under continuous canola cropping, pest populations increase, especially if the pest has limited mobility. Diseases that survive in the soil (such as seedling diseases, root rots, and clubroot) or on crop residue (such as blackleg) fall into this category, as would most weeds. "It can be tempting to stray from the recommended one-in-four canola rotation, particularly when canola prices are high. However, over the long term, following the recommended canola rotation can provide better yields with reduced risk for all crops in the rotation. "Keep in mind that there is a new strain of blackleg in some parts of the prairies. Old diseases are changing and new diseases are being found. It's even more important that growers pay attention to canola rotations," stresses Hammond.
For blackleg, where varietal resistance is the main control option, growing resistant varieties under short rotations selects for the most virulent strains of the fungus. The disease can eventually overcome the resistance mechanism.
"A one-in-four canola rotation combined with good sanitation practices is very effective in limiting the spread and buildup of new strains of a disease, like blackleg, and new diseases, like clubroot," says Hammond. The impact of a diverse crop rotation on weeds is partly due to differences in crop competitiveness, which prevents shifts in the weed spectrum within a field. For example, a high canola frequency in a field will favour cruciferous weeds. Growing cereals in the rotation, however, can shift the spectrum to more grassy weeds. Another great benefit of a diverse crop rotation is the opportunity to use a range of different herbicides not used in canola, providing improved overall weed control in the long term. The use of different herbicide groups also helps prevent the buildup of resistant weeds. However, he cautions growers to be sensitive to re-cropping restrictions and potential herbicide residue problems as they plan rotations.
Diverse crop rotations also provide other benefits. Rotating crops with different rooting systems and depths can result in improved water use efficiency for the farm. A combination of cereals, oilseeds, pulses and forages results in a variety of crop residues that can improve soil aggregation and nutrient cycling. As well, yields for the entire farm will tend to be more stable.
"The bottom line: A well planned crop rotation can reduce pest pressure, leading to improved yields, less reliance and use of chemical controls, and improved farm profitability," says Hammond.
Agnet is produced by the Food Safety Network at the University of Guelph and is sponsored by the Ontario Ministry of Agriculture and Food, Plants Program at the University of Guelph, Agricultural Adaptation Council (CanAdapt Program), AGCare, Canadian Council of Grocery Distributors, ConAgra Foods Inc., Meat Livestock Australia, Pioneer Hi-Bred Limited (Canada), Monsanto Canada, National Pork Board, Syngenta Seeds, Inc. USA, JIFSAN, CropLife Canada, Canadian Animal Health Institute, National Cattlemen's Beef Association/Cattlemen's Beef Board, Burger King Corporation, Southern Crop Protection Association, Ag-West Biotech Inc., Ontario Agri-Food Technologies, Syngenta Crop Protection, Feedlot Health Management Services, Institute of Environmental Science Research Limited , National Food Processors Association, Tactix Government Consulting, Inc., CanAmera Foods, Global Public Affairs, and Agri Business Group, Inc.
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