Group 14 herbicides are part of a group of chemistries that require light to be effective as an herbicide. In Canada, one of these compounds is called Heat (saflufenacil), and is a protoporphyrinogen oxidase (PPO-inhibiting) herbicide. There are other light-dependent herbicides, as well. Photosystem II (PS II) is a chemistry that interferes with photosynthesis and disrupts plant growth. An example would be AAtrex (atrazine) (Group 5). There’s also inhibitors of PS I, another part of photosynthesis, including compounds like Gramoxone (paraquat) (Group 22). These two chemistries are related and affect the transfer of electrons within photosynthesis.
Plants also need chlorophyll and carotenoids for photosynthesis to occur, and there are compounds that are inhibitors of PDS like Solicam (norfluzaron) (Group 12). Another compound inhibits one of the precursors to the carotenoid pathway such as Command (clomazone) (Group 13). Some of the new chemistries, the HPPD inhibitors like Callisto (mesotrione) (Group 27), are also part of this class of chemistries. All of these are called light-dependent herbicides because they affect one aspect or another of photosynthesis, either through the transfer of electrons or the synthesis of the pigments, and require light to be active.
I’ll be talking about PPO inhibitors, an enzyme that is involved in porphyrin and chlorophyll synthesis. Why do we care about these compounds? When they work they work really, really well. PPO-inhibiting herbicides were first commercialized in the 1960s and their market share in the U.S. reached about 10 per cent in the late 1990s. A lot of herbicides have been synthesized that target this enzyme or pathway. About 100,000 compounds may have been synthesized that can inhibit this enzyme. Of course not all of them make it to be an herbicide.
These PPO-inhibiting herbicides were initially used mostly as post-emergent, broad-spectrum weed control in soybean fields. That’s how they were primarily used for the longest time. Some like carfentrazone (Aim in Canada) were developed for cereal crops. Some were so active that they were used as non-selective herbicides.
Mode of action
When the herbicide is applied, it lands on the leaf surface and then goes through the top layer, called the cuticle. It goes through the epidermis, and then has to get to the target site. There it inhibits an enzyme that produces a compound called Proto IX. Proto IX is supposed to be in the chloroplast, but when you apply the herbicide, Proto IX accumulates outside of the chloroplast. When the sun comes out, Proto IX reacts with sunlight, what’s called reactive oxygen degradation, and basically destroys the cell structure of the plant. Within a few hours the plant dries up. It becomes paper-thin and completely dehydrates. Injuries like leaf cupping, crinkling, and bronzing appear on some plants, and then typically necrosis and completely dead tissue within a few hours. It’s a pretty fast-acting herbicide, and it works really well under the right circumstances.
Some plants are very sensitive because they can’t metabolize the herbicide. Some plants are very tolerant because they metabolize the herbicide very quickly. Since some plants can metabolize it very quickly, a plant can become resistant by developing the ability to metabolize this chemistry, which would be non-target site resistance.
Most PPO inhibitors degrade very quickly in the environment. Most compounds have a very short half-life and have very poor pre-emergence activity. However, a compound like sulfentrazone (Authority; Authority Charge) can have a very long half-life, 280 days. In the south US that may actually affect rotation of your crops because of the long residual activity of some of that chemistry.
[Ed. Note: In Canada, carfentrazone has a short half-life and when used as a pre-seed treatment, there are no cropping restrictions. Sulfentrazone’s longer half-life means it can be used as a pre-seed surface application that provides residual weed control, but also means there are re-cropping restrictions.]
The PPO inhibitors are very rapidly metabolized and don’t stick around in water. They’re considered to be a pretty safe chemistry.
A resurgence in use
There used to be a lot of use of the PPO chemistries in the 1990s. In 1996, the first Roundup Ready crops were introduced and their use dramatically decreased. Where PPOs were used extensively for weed control in soybean, it was replaced by glyphosate. But the use has picked up again because of glyphosate resistant weeds. It is a great tool to manage glyphosate resistant weeds in the south and the Midwest as well. In Canada it might be a good tool in the future as you see more and more glyphosate resistant weeds.
Some plants have become resistant to PPO chemistry. For most of them we don’t know the mechanism. But for waterhemp, Palmer amaranth, and ragweed, we know there have been mutations on the target site gene. That’s similar to what happens with ALS inhibitors and ACCase inhibitors. That’s what happens with some glyphosate resistance in some cases.
At the target site, there are two genes that make two proteins. One goes to the chloroplast; one goes to the mitochondria. When the plant became resistant, many scientists sequenced the gene for the protein that goes to the chloroplast because that’s where the herbicide works by preventing chlorophyll synthesis. However, no mutation was found at that location. Dr. Tranel at the University of Illinois sequenced the other gene that goes to the mitochondria. He found that there was a mutation where a whole amino acid was removed, and that was kind of unusual. But there was also something added to the gene, and that was the first time this was reported to happen in plants.
This was very unusual. The herbicide is supposed to inhibit the chloroplast enzyme, but that little bit of DNA that was added to the sequence made the mitochondrial gene also go the chloroplast. So now you have a plant cell where a resistant trait is in both locations – the mitochondria and the chloroplast.
That’s important because these resistant plants now have the capacity to do the deletion and develop resistance, and have the capacity to move it to both locations. This has proven to be true in Palmer amaranth, water hemp, and ragweed. There’s no other herbicide so far that we know where plants have become resistant by this mechanism.
We looked at many genetic sequences to look for all the potential plants that have the same gene structure that could have a deletion. One of the plants is kochia. Kochia is a big weed in Colorado and in Canada. We now know that kochia is already predisposed to that mutation. If we keep using PPO chemistry the way we’ve been doing it and try to control kochia, most likely kochia will become resistant to that chemistry in exactly the same way that Palmer amaranth has become resistant. If you know a weed is predisposed to the mutation, then you should be scouting for weed escapes when you use that herbicide.
Now because you have resistance doesn’t mean you have resistance. What? Some interesting research was conducted by Peter Sikkema in Canada where fleabane escaped control by PPO chemistry. He demonstrated in the greenhouse that those seeds he collected in the field were resistant. What’s interesting is he went back the next year to the same field, applied the same herbicide and had 100 per cent control. An escape does not mean that your field is infested with the resistant weeds. In this case, it could be that the resistant weeds did not over-winter very well. So be on the lookout, but don’t freak out. If you have an escape it could be just something that’s a freak accident. But always be on the lookout for those escapes because we know that it can happen.
I’m not very familiar with the Canadian system, so suggested management strategies come from Arkansas where they deal with PPO resistance all the time in soybean. These may not necessarily be applicable to Canada. Use two active ingredients at planting, typically metribuzin (Group 5) and a Group 15 such as acetolachlor. Both are needed for successful residual activity. Then 21 days later use a post-application of glufosinate (Group 10), dicamba or 2,4-D (Group 4s) tank mixed with Dual (s-metolachlor; Group 15) for additional residual activity. In Arkansas, glyphosate is not useful because most major weeds including PPO resistant biotypes are already resistant to glyphosate. ALS herbicides are not useful in Arkansas either, as about 50 per cent of weeds have resistance to this group.
For more stories on this topic, check out Top Crop Manager's Focus On: Herbicide Resistance, the first in our digital edition series.
According to the conditional approval from the United States Department of Justice, the integration of Monsanto into Bayer can take place as soon as the divestments to BASF have been completed. This integration process is expected to commence in approximately two months.
The name Monsanto will soon cease to exist. All the acquired products will be moved under the Bayer portfolio but retain their brand names. Bayer Crop Science will also move its North American headquarters in North Carolina to Monsanto's facilities in St. Louis.
“Today’s closing represents an important milestone toward the vision of creating a leading agricultural company, supporting growers in their efforts to be more productive and sustainable for the benefit of our planet and consumers,” said Hugh Grant, outgoing chairman and CEO of Monsanto. “I am proud of the path we have paved as Monsanto and look forward to the combined company helping move modern agriculture forward.”
Liam Condon, member of the Bayer board of management, will lead the combined crop science division when the integration commences. Until that time, Monsanto will operate independently from Bayer.
Find more information at www.bayer.com and view Bayer's full media release
When you think of a radish, you may think of the small, round, crunchy, red-and-white vegetable that is sliced into salads. You might be surprised to learn that a larger, longer form of this root vegetable is being used in agriculture as a cover crop.
Cover crops are grown between main crops such as wheat, corn, or soybeans when the soil would otherwise be bare. Cover crops can control erosion, build soil, and suppress weeds. Radish as a cover crop can provide these benefits and more. The long radish root creates deep channels in the soil that can make it easier for subsequent crops to reach water in the soil below.
Radish is also known to benefit water quality. It does so by taking up nitrogen, in the form of nitrates, from the soil. This leaves less nitrogen in the soil that can run off to nearby streams and lakes.
Matt Ruark of the University of Wisconsin-Madison and colleagues wanted to know more about the effect of this nitrate uptake in the following growing season. They established test sites in three Wisconsin locations and studied them for three years. At each site, some plots received the radish cover crop and some did not. The radish cover crop was planted in August after a wheat harvest. Corn was planted the following spring.
The research showed that radish significantly reduced the nitrate content in the soil as compared to the test plots with no cover crop. This finding confirmed the results of several earlier studies. It showed that radish did take up nitrogen, in the form of nitrates, from the soil.
This research supports the use of radish as a cover crop as a trap crop for fall nitrogen. However, what happens to that nitrogen afterward remains unknown.
There was no consistent evidence that nitrogen was returned to the soil as the radish crop decomposed. Radish did not supply nitrogen to the corn crop. The researchers concluded that in the Upper Midwest the nitrogen in radish could not replace fertilizer.
Ruark commented, “Radish grows well when planted in late summer and traps a lot of nitrogen. But the way it decomposes doesn’t result in a nitrogen fertilizer benefit to the next crop. We don’t know exactly why. We were hoping it would provide a nitrogen benefit, but alas, it did not.”
What happens to the nitrogen? The decomposition pattern of radish needs to be explored more fully to learn more. And perhaps, Ruark said, radish could be more beneficial if mixed with a winter-hardy cover crop.
Corteva Agriscience brings together DuPont Crop Protection, DuPont Pioneer and Dow AgroSciences to create a standalone agriculture company with positions in seed technologies, crop protection and digital agriculture.
The company says it will continue to invest in brands including Pioneer, Mycogen and the newly launched Brevant seed brands.
The corporate name, brand identity and logo were unveiled earlier this week at Commodity Classic. The corporate headquarters for the intended company will be located in Wilmington, Del., and will include key corporate support functions. Sites in Johnston, Iowa, and Indianapolis, Indiana, will serve as Global Business Centers, with leadership of business lines, business support functions, R&D, global supply chain, and sales and marketing capabilities concentrated in the two Midwest locations.
The awards are for the BalerAssist feature on the large square balers and the Plus2 Bale Accumulator for large round balers, both introduced in late 2017. The AE50 Award highlights the year’s 50 most innovative designs in product engineering in the food and agriculture industry, as chosen by a panel of international engineering experts.
The BalerAssist option on the L331 and L341 Series Large Square Balers was recognized for allowing the operator to more quickly and easily clear plugs between the baler pickup and rotor, without leaving the tractor cab.
“This significantly reduces downtime and increases bale-making productivity, especially in tough crop conditions,” says Travis Roe, senior marketing representative for large square balers. “In addition, this feature makes it easier for operators to access service points inside the baler and improve overall operational control and maintenance.”
Also receiving an award are the A520R and A420R Plus2 Round Bale Accumulators, which give customers the ability to carry up to two round bales behind the baler while making a third bale in the chamber. The Plus2 Accumulators are fully integrated into the design of the balers and can be used with 6-foot (1.82 m) diameter John Deere 7, 8, 9 and 0 Series Round Balers.
“These accumulators allow operators to strategically place the bales where they can be removed from the field most efficiently,” says Nick Weinrich, product marketing manager for pull-type hay tools. “This dramatically reduces the damage to crop regrowth from excessive field travel, as well as fuel and labor associated with collecting individual bales scattered across the field.”
ASABE is an international scientific and educational organization dedicated to the advancement of engineering applicable to agricultural, food and biological systems. The awards will be presented at the ASABE Agricultural Equipment Technology Conference in Louisville, Kentucky, in February. Information on all award winners will be included in the January/February 2018 ASABE’s Resource magazine and on the ASABE website. Further information on the Society can be obtained by visiting www.asabe.org/.
That was a key message by long-time Iowa State University weed scientist Mike Owen in his 2018 weed management update presentation at the Integrated Crop Management Conference in November. He noted the management practices used by many farmers are leading to more resistance to herbicides, and he doesn’t foresee an end to that anytime soon. For the full story, CLICK HERE.
Join Top Crop Manager Feb. 27 and 28 in Saskatoon, Sask., for the 2018 Herbicide Resistance Summit - Register now!
Introduced in 2017, 5R Series Tractors leverage existing technologies normally found in large tractors and feature four models ranging from 90- to 125-engine horsepower.
“John Deere engineers designed tractor features to provide customers with unrivaled maneuverability, an easy-to-use transmission, increased visibility, loader integration and operator comfort,” said Nick Weinrich, product marketing manager for Deere.
A 7.4-foot (2.25 m) wheelbase, paired with a 60-degree steering angle, provides a tight turning radius of 12.1 feet (3.68 m). “For customers working in confined areas such as barns, this is a big improvement because they can more easily maneuver the tractor while increasing their productivity,” said Weinrich.
Customers can choose from two fully electronic transmission options, CommandQuad Manual and Command8. Weinrich said Deere made it easy for operators to toggle from B range through D range without stopping, thanks to a multi-range selection feature. Base equipment on 5R Tractors also includes AutoClutch, a feature leveraged from larger Deere row-crop tractors that completely eliminates the need for clutching. Operators can automatically re-engage the clutch by depressing the brake pedal.
Deere engineers improved upward and forward visibility from the tractor to help make 5R Series Tractors an even better fit for loader applications. Engineers also integrated an interactive display into the tractor’s right hand cornerpost. Operators can use the display to customize a variety of tractor functions to fit their preferences.
Join Top Crop Manager Feb. 27 and 28 in Saskatoon, Sask., for the 2018 Herbicide Resistance Summit - Register now!
Susanne Veatch, Kinze president and chief marketing officer, said the new Mach Till high-speed disc products support farmer interest in faster tillage that enables them to stay ahead of the planter and be more productive by covering more acres in less time.
"Farmers will now be able to obtain three types of equipment from their Kinze dealer, all with the same standard of quality," she said.
The new product line is based on a Canadian design, produced by Degelman Industries, that has been licensed to Kinze to build at its manufacturing facility in Williamsburg, Iowa. Kinze will exhibit one of its first tillage models - the Mach Till 331 - at the 2018 National Farm Machinery Show Feb. 14-17 in Louisville, Kentucky.
"We are constantly evaluating opportunities in the market for new products that would be a good fit for Kinze," Veatch noted. "The Mach Till product line allows us to improve our already strong brand and have instant access to the growing high-speed disc segment with an already proven product."
In addition to high speed (8-12 mph) and high capacity, the versatile Mach Till lineup also offers simple setup and ease of use, maintenance-free parts and the ability to perform in various soil types, from fall primary tillage and residue management to spring secondary tillage and seedbed preparation.
The product is built heavy for high speed and deep working depth, but provides great flotation for lighter seedbed preparation that minimizes soil compaction. Veatch said the tillage products will be available from Kinze dealers in the United States and Canada, as well as for export to customers in Eastern Europe and Russia. Pricing information will be released this spring, with product availability beginning in fall 2018.
Join Top Crop Manager Feb. 27 and 28 in Saskatoon, Sask., for the 2018 Herbicide Resistance Summit - Register now!
O&T Farms is a proven leader in the Omega-3 animal feed ingredient market, using its patented dry-extrusion process in the manufacturer of linPRO and linPRO-R. These specialty feed products aid in the consistent and reliable enrichment of Omega-3s into eggs, dairy and meats. The organic LinPRO products now provide the same nutritional advantages of enhanced digestibility, energy availability and improved rumen escape values only now using verified organic ingredients.
“We always strive to be responsive to changing markets, such as the incredible growth in organics, and develop products that allow our customers to be as versatile and serve as many markets as possible,” says Elan Ange, CEO of O&T Farms. “The organic certification of linPRO(organic) and linPRO-R(organic) means our flaxseed-based products can offer animal health and production benefits to a wider range of livestock producers. They open the door for the production of Omega-3 enriched organic alternatives for consumer food products such as milk, eggs, beef and chicken.”
LinPRO and linPRO-R are certified through International Certification Services Inc. under the National Organic Program (NOP) in accordance with USDA Agricultural Marketing Services and the Canadian Organic Regime (COR). The LinPRO brand offers high-energy, flaxseed-based feed products with high levels of fatty acids and amino acids.
The Omega-3 fatty acids contained in flaxseed have been associated with many animal and human health benefits. Omega-3 fatty acids have been shown to provide immunological benefits and potential production benefits to livestock, as well as human benefits that include improving brain and eye health and lowering the risk of heart disease, depression, dementia and arthritis. Additionally, feeding linPRO branded products to livestock is a natural way to improve the nutritional value of the end product (i.e. milk, eggs and animal protein) and therefore offer healthier alternatives to consumers.
RELATED: Flaxseed in animal feed has exciting potential
CMC is a leading supplier of hazard monitoring sensors and systems used in agricultural material handling applications. CMC also manufactures commercial bin monitoring sensors and systems. Founded in 1997, CMC has locations in Burnaby, B.C., and Minneapolis, MN. CMC has strong relationships with domestic and multinational customers and provides AGI with new products to better serve its customers in an environment of increasingly stringent safety standards.
JCI is a leading manufacturer of automation, measurement and blending systems for the agriculture and fuel industries. Founded in 1979, JCI is based in Cedar Rapids, Iowa. JCI's precision blending and measurement systems, focused primarily on liquid fertilizer blending, are highly complementary to AGI's fertilizer product offering and further broadens AGI's fertilizer platform.
The acquisitions of CMC and JCI add significant strength to our applied technology platform, and continue to evolve our product and solution portfolio enabling us to serve current and future customers with broader solutions. AGI is proud to welcome the teams from CMC and JCI to the AGI family.
The John Deere S700 Series Combine was recognized for its significant innovations in “smart” technology, improved operator comfort and data capabilities for more efficient grain harvesting, said Matt Badding, John Deere marketing manager for harvesting equipment.
“The S700 Combines integrate new technologies that optimize and automate grain harvesting, making it easier, faster and more efficient for the operator,” Badding said. “By automating more adjustment and calibration tasks, we’ve enhanced the operational intelligence of these machines while improving overall durability and productivity, based on each customer’s crop and field conditions.”
The latest features include the Combine Advisor package that incorporates seven technologies to help operators set, optimize and automate the combine performance as crop conditions change; Auto Maintain and ActiveVision cameras for maximum threshing performance and grain quality; and Active Yield technology that automatically calibrates the mass flow sensor to eliminate the need for manual calibrations and ensure the best data is collected during harvest.
In addition, the CP690 Cotton Picker and CS690 Cotton Stripper were recognized for innovations in precision cotton-harvesting technologies that include moisture sensing, round module weighing, Harvest Identification, Cotton Pro and John Deere Operations Center Field Analyzer.
ASABE is an international scientific and educational organization dedicated to the advancement of engineering applicable to agricultural, food, and biological systems. From the many entries submitted each year, an expert panel of engineers selects approximately 50 products for recognition. The award-winning products are those ranked highest in innovation, significant engineering advancement and impact on the market served.
Ehler Bros. Seed has been doing early planting soybean trials since 2009. Although the Feb. 22 planting date the company experimented with this past season may sound a little extreme, Ehler advocates planting full-season soybeans (normally groups 3.5 to 4.2, with 4.7 soybeans tossed in this year) no later than the end of April. For the full story, click here.
RELATED: Dating decisions - How critical is soil temperature for soybean planting date decisions?
Wild-type soybeans contain bloom, a powdery substance originating in the pod that can coat seeds. This trait makes the seeds less visible and is believed to be advantageous for their long-term survival in natural environments. But the bloom is enriched with allergens and can be harmful for animals and people if ingested. People domesticating soybeans selected a naturally occurring mutation that makes soybean seeds shiny through eliminating bloom. For the full story, click here.
As part of these efforts, Minister MacAulay travelled this week to Nashville, Tennessee, where he delivered a keynote address to the American Farm Bureau Federation's (AFBF) annual convention. Minister MacAulay reiterated the importance of NAFTA as an engine of growth and prosperity for Canada, the United States and Mexico.
While in Nashville, Minister MacAulay participated in a roundtable with key U.S. agricultural producer and business groups to discuss opportunities for cooperation, hosted a breakfast for all State Farm Bureau Presidents, met with Zippy Duvall, President of the AFBF, with Kevin Paap, Minnesota State Farm Bureau President, and with Jai Templeton, Commissioner of Agriculture for Tennessee, to discuss bilateral trade opportunities. He also met with AFBF Young Farmers and Ranchers.
"The Canada-US relationship is strong, balanced and beneficial to both of our great nations. The Government of Canada is committed to continue working with the United States to strengthen our partnership for the good of our businesses, our jobs, our citizens and our economies."
- The Honourable Lawrence MacAulay, Minister of Agriculture and Agri-Food
- Canada and the United States are each other's largest trade partners for agriculture and agri-food, with bilateral agriculture trade reaching $62 billion (CAD) ($47 billion (USD)) in 2016.
- Canada is the top agriculture and agri-food export market for 29 states.
- Canada-United States trade supports millions of middle class jobs on both sides of the border.
- The AFBF is a non-partisan, non-sectarian national organization that represents farm and ranch families at all levels.
- The AFBF convention is a gathering of more than 5,000 delegates bringing together agricultural producers from all levels and sectors representatives from the local, state and national levels.
'Soil Your Undies' experiment in EloraMon Jul 23, 2018 @10:00AM - 11:00AM
Intercropping Field DayTue Jul 24, 2018 @10:00AM - 05:00PM
Manitoba crops-a-PALOOZAWed Jul 25, 2018 @ 8:00AM - 05:00PM