A survey of field and horticultural crops across the province seeks to update provincial nematode distribution maps and establish baseline data for six different nematode species including SCN.

Why it matters: There are gaps in nematode awareness and management options so survey data can be used to help farmers better manage problems.

Albert Tenuta, field crops pathologist, and Katie Goldenhar, horticulture crops pathologist with the Ontario Ministry of Agriculture, Food and Rural Affairs, are working on the survey. Target species include SCN, root lesion and other nematodes, and the project doesn’t place any higher importance on one versus another.

“The results will support the enhancement of current nematode best management practices for field and horticultural crop farmers,” says Tenuta. “Participating in the nematode survey is free, easy, and soil samples can be collected specifically for nematode testing or alternatively, soil samples collected for soil fertility can be split.”

“The yield impact of many nematodes, such as cyst, needle, stunt, root lesion, lance, stubby and pin, on Ontario’s horticultural and field crops has been ignored, misdiagnosed or not well understood” says Tenuta.

“Compounding these issues is nematodes are difficult to identify in the field since many of the typical symptoms they cause could be the result of other common problems such as herbicide injury, pH or nutrient deficiencies.”

Further complicating the issue is that above-ground symptoms may not be visible, which results in significant yield losses.

Root lesion nematode can be troublesome because it has a wide host range with substantial economic impact. In 2009, a limited survey of 90 fields from Windsor to Toronto found 38 per cent of samples were considered above root lesion thresholds established in the United States.

Ontario thresholds for root lesion and other nematodes in field, horticultural and other crops have yet to be developed and will be a metric of this project.

Since many nematode species can infect and injure multiple crops, the distribution and population data obtained from this survey will relate to many Ontario crops.

“Nematode activity often goes unnoticed but they can often produce many openings or wounds on the roots,” says Tenuta.

“This allows secondary plant pathogens (like root rot organisms) easy access to the roots, resulting in additional plant health issues such as shallow or weak root systems with increased browning. They’re also prone to further environmental stress.”

Options to manage nematodes are limited and although there are new seed treatment nematicides, there aren’t any silver bullets. Preventive measures are key.

Crop rotation has limited effect against certain nematodes, including root lesion nematode, because of the pest’s many potential hosts.

Survey objectives are as follows:

• Collect baseline information on the distribution and population densities of plant parasitic nematode species across the province to gain a better understanding of potential for yield loss.
• Develop thresholds for root lesion nematodes and others, if possible. Research plots could be established in fields with known nematode problems as a result of the survey, which could be used to develop or validate thresholds for various nematode species in the province.
• Develop best management practices and increase awareness of nematodes that adversely affect field and horticulture crops in Ontario. Knowledge translation and transfer resources will be developed in conjunction with stakeholders such as the Grain Farmers of Ontario and Ontario Fruit and Vegetable Growers Association to increase industry knowledge and diagnostic capabilities with nematodes.

More information and a submission form are available by contacting Katie Goldenhar at katie.goldenhar@ontario.ca or Albert Tenuta at albert.tenuta@ontario.ca.

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Nick Toll has tried another option. The Blenheim, Ontario-area producer is the fourth generation on the family farm, managing a corn, soybean and winter wheat rotation, with some additional acres for winter canola, seed corn and alfalfa. The family also operates a 500-head commercial ewe flock, and his brother finishes a few cattle.

Toll has been planting Croplan WinPak soybeans from WinField United Canada for the past three years, taking advantage of the company’s approach of blending two complementary varieties.

It’s not an entirely new theory for spreading risk. For years, agronomists, crop advisors, researchers and extension personnel have urged growers to plant more than one soybean variety (or hybrid) across their fields. The logic is simple, and mirrors the WinPak concept of balancing growth characteristics or strengths of different varieties. The difference is the company’s approach to alleviate the work of pairing and packaging varieties.

READ MORE: Managing white mould in soybeans

Seed is selected based on specific attributes in a field, with high yield potential on more productive soils while providing more consistency for the challenging spots. A single bag contains two varieties from the same trait platform — either Roundup Ready 2 Xtend or Enlist E3s. The goal is to find a complementary performance from each: one variety might have better standability, while the other performs better under drier conditions. The varieties will also have similar maturities to ensure consistent dry-down in the field.

First launched in the U.S. more than 10 years ago, Croplan WinPaks are now available across Canada in the 2200 to 3375 CHU regions, with nine paired options for the eastern half of the country and four in the West.

For Toll, the WinPak option means he doesn’t have to invest in variable-rate planting technology and can stay with a no-till drill for his soybeans.

“A lot of our fields have varying soil types from one end to the other, so the WinPak allows us to get at least half of the correct seed on the varying knolls or bottoms,” says Toll, who farms with this father Ian and brother Ben. “I believe it takes a bit of drought concern out of the equation as well. One of the varieties is more defensive and will hold its own in less-than-ideal conditions, whereas the other variety will excel when conditions are favourable.”

A changed approach

When Croplan WinPak first launched with limited availability in Canada in 2019, there were references to “defensive and offensive” characteristics as part of the blends. But according to Kaitland Miller, WinField personnel have more recently adopted the “complementary” term to describe the benefits.

“Varietal mixtures can be advantageous as you have two soybean varieties working for you in the field,” says Miller, WinField United’s market development manager for Ontario. “There can even be a synergistic effect on an individual product level. For example, the CP2421WPX has improved field stability paired together in a WinPak, as one soybean component is able to hold up the other high-yielding soybean component, improving harvestability and yield.”

That happens to be the varietal blend that Toll plants. One variety is CF3176, a taller, top-performing clay variety which also yields well in loam soil but can grow a little taller and be prone to lodging. The partner variety is CP2320, a shorter, bushier-type soybean that chases top-end yield on lighter and loamier soil.

Toll maintains the blended concept alleviates some concern about drought. It may be anecdotal, but he echoes Miller’s contention of a synergistic effect with the complementary varieties, almost a 1 + 1 = 3 relationship.

“Not only will they perform well on their ideal soil type, but the 2320 will actually help hold up the 3176 in ideal conditions, allowing them all to excel without lodging,” he says, noting he doesn’t have actual data to show an advantage. “But the varieties in the WinPaks we grow are varieties we had grown on their own in the past that performed very well for us.”

Single charge

Miller says there’s no added cost for the WinPak service.

“We keep it simple for the grower — we do the research and logistics work so the grower simply plants the combined varieties as they come out of the bag or tote, pre-blended for their convenience. We must also ensure we have similar seed sizing for each WinPak component, not to mention the extra effort that goes into the blending and packaging.”

Research by WinField indicates pairing two varieties provides a consistent two- to three-bushel per acre yield advantage, on average. Miller says interest in the Croplan WinPak option has picked up in the past few years as word has spread from growers who see the benefits on their farm.

“To keep it simple, the number one response I get from growers is, ‘That makes sense,’” she says. “I love that answer because agronomically, the WinPak concept helps farmers manage field variability and risk mitigation. They know planting several varieties is a good idea, and this way is easy.”

– This article was originally published as ‘ A new option for variability’ in the 2023 edition of Soybean Guide.

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Peter VanderZaag has spent much of his farming career investing wisely in new equipment, securing contracts and growing his Sunrise Potato Storage business in Alliston, Ont., to where it is today. But VanderZaag’s journey required a firm and ongoing commitment to change, first in terms of soil health and productivity, and then in meeting his customers’ demands for quality and consistency while incorporating new technologies. Given his starting point, the changes were neither quick nor simple.

“Most farmers understand they have to do this,” says VanderZaag, who grew up on a family farm near Alliston in the 1950s. “You cannot get a mediocre crop — you need an excellent crop. You have to have everything done right, and that starts with good soil health and good soil management … and then good seed and good management of the crop as it grows.”

As a child helping out on a farm which included cows, hogs and potato, grain and hay production, VanderZaag says he learned the value of diverse cropping practices. Sustainability was possible, even with 100 acres.

However, from 1963 to 1980 there was significant expansion of monoculture potato production in southern Simcoe County where the farm was located. VanderZaag says diverse crop rotations and livestock production were abandoned across much of the district and soils began to show signs of deleterious pathogen levels as well as water and wind erosion, with frequent sandstorms in the area. Then interest rates spiked in the early 1980s and farm productivity collapsed, he adds, and numerous producers in the region abandoned potatoes altogether following a disastrous growing season in 1986.

VanderZaag eventually became a potato scientist, and in 1991 he and his wife Carla returned to Canada after living abroad for decades. The couple set their sights on potato production and leased several abandoned farms in an area north of where VanderZaag grew up.

Seeing the impact of soil degradation in many parts of the world, the VanderZaags realized soil heath and crop diversity would be key to their farming success and they could also serve as an example for others to consider. They embarked on a 16-year journey in returning the soils on their farms to full productivity, employing many of the regenerative agricultural practices they had learned from their travels.

Three of the farms the VanderZaags rented and later purchased couldn’t sustain barley production the first season, while four rented farms still had potato ridges left from previous years, with volunteer trees growing in some spots. Their first two measures were to install some tile drainage and then secure an agreement with a local beef producer for liquid manure to be applied annually to the fields. Other measures included adding irrigation to fields and selective seeding of cover crops on less productive areas, as well as variable rate applications of potassium, lime and gypsum.

READ MORE: Where did potato production land in 2022?

Doing more with less

VanderZaag, whose daughter Ruth and son-in-law Nick Ploeg now play a leading role as farming partners, says in spite of high fertilizer and fuel prices and increasing demands from processors for supply, quality and consistency, Sunrise has managed to “do more with less” — a common refrain in agriculture these days.

“With potatoes we use more fertilizer and more diesel fuel than most (crops) per acre of land,” he says. “We bought a lot of our fertilizer last year before the prices went up. Whatever we could pre-order and pay for, we did, and that helped to some extent. But … we couldn’t order (fuel) in advance and then nitrogen costs went up, so it all adds up.”

VanderZaag says having contracts with three chipping processors with plants in both Canada and the United States and also some timely investments in equipment have enabled Sunrise to weather some of the cost volatility of late.

About six years ago the farm invested in a Tomra optical sorting system, which VanderZaag says cuts down on labour required for sorting and also lessens the chance of reduced quality or a loss of confidence by their buyers, the processors.

“If you don’t have that system, your potatoes may be considered of inferior quality at the plant because they’re not as clean, not as well sorted,” he says. “If you find a walnut in your potatoes, for example, you’re in trouble. Those are all things that have now become an issue.”

For VanderZaag, the 2023 potato season brings a blend of optimism and caution. In spite of forecasts of a recession, he says, economic downturns can have an interesting benefit — consumers increase their chip purchases during harder financial times. There’s also the Canadian dollar’s relative weakness compared to the U.S. dollar, which becomes a substantial advantage for shipping potatoes south of the border.

“Our problem is that demand exceeds our supply, both locally and to the northeastern United States,” says VanderZaag. “Brokers like W.D. Potato (potato wholesaler) want more potatoes because they can’t fill contracts, or they want bigger contracts. That’s something in our favour, but the flip side is to buy a new digger or windrower or a tractor, the prices are through the roof.”

Added to that is the impact of interest rate hikes. “I hope it’s not like the ’80s with 18 per cent interest,” says VanderZaag. “My father told me when I came back to the farm, ‘Don’t spend a dollar unless you have a dollar’ because he’d gone through the ’80s. We have to be very careful not to spend too much money because that interest eats you up pretty quick.

– This article was originally published in the 2023 edition of the Potato Guide.

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Disease management has greatly improved in the past 10 to 15 years. One reason is the enhanced genetics, along with efforts to screen out seed lines showing susceptibility to specific diseases. Another is learning how to use newer fungicides — growers have certainly “upped their game” with help from agronomists and advisors. Finally, there’s a better understanding of the physiology of diseases and the relationship between pathogen, host and environment, and how if one “corner” of that triangle is missing, there can be no infection.

Yet white mould is that constantly nagging issue for many growers in eastern Ontario and into Quebec, almost to the point where it’s a greater concern than SCN or SDS. According to data from the Crop Protection Network (cropprotectionnetwork.org), 2021 saw an estimated 1.21-million-bushel loss due to white mould in Ontario, making it the third-highest yield-robber behind SCN and SDS.

Sheila Murphy says affected growers have learned to rely on best management practices to reduce infection and protect their yields.

“The fungus Sclerotinia sclerotiorum is endemic to Eastern Canada and overwinters here, so the inoculum is present,” says Murphy, Corteva Agriscience seed product agronomist for Eastern Canada. “We know in eastern Ontario and western Quebec there’s a continued concern about white mould, whereas in southwestern Ontario, it’s not as concerning, and I think that’s largely attributed to the climate.”

Historically, crop advisors in parts of southern Ontario have encountered pockets of white mould, often in dairy operations. The addition of manure provides the moister environment to help white mould flourish. But the disease’s impact is much less in that region compared to SCN, SDS and a few others that can pop up from time to time.

The focus on white mould comes with the launch of Pioneer’s A-Series Enlist E3 soybeans, with 21 varieties available in a range of maturities for Eastern Canada. The A-Series offers a suite of enhanced traits that are expected to help with resistance to SCN, SDS, Phytophthora root rot and white mould.

Murphy says the Enlist E3 and A-Series bring together the strong agronomics of the A-Series, “Plus there’s the Enlist E3 tolerance which allows growers to use the E3 program with stronger products.”

Likes it cooler

For eastern Ontario, the environment is arguably the key. Although there are more dairy operations, it’s the tendency for air temperatures below 28 C that seems to be the key. According to resources from the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), “White mould prefers temperatures below 28 C, moist soils and high humidity.”

For Darren McColm, that reflects conditions in eastern Ontario.

“There are instances of white mould in almost every county in Ontario,” says McColm, agronomy lead (east) for WinField United Canada. “However, parts of eastern Ontario see those moderate temperatures increasing the potential for the disease. White mould instances can vary from farm to farm depending on rotation, cultural practices and even soil types.”

Like Murphy, McColm believes agronomic practices can make a bigger difference, including wider rows, longer rotations and paying attention to high-fertility field conditions. Higher fertility increases vegetative growth that traps moisture in the canopy and provides an optimal environment for white mould. He also stresses row width and plant populations as key agronomic factors to combat the disease.

“You can also plant a variety with high tolerance,” says McColm. “No variety is a silver bullet but if you have bad white mould in the past, you can mitigate risk with a variety that’s rated for high tolerance.”

Murphy also cites the “silver bullet” reference, adding there is no complete resistance factor for the disease, meaning there’s no “easy button” other than best management practices. As much as breeders can work to impart characteristics that battle stresses, there is only one real metric that interests growers: yield.

“With any crop that we’re breeding, we have to balance all of those desired traits, whether it be yield, disease resistance or drought tolerance,” says Murphy. “Mother Nature throws everything at us, but for our growers, white mould is a concern, and it’s a very large part of what we do in the breeding programs — continuing to breed for yield, SCN and SDS resistance. But white mould is something we’re actively engaged in bringing tolerant varieties to the marketplace.”

The right tools

In the absence of any “total package” soybean variety, growers must manage using agronomic practices but they also have a good selection of fungicides. McColm mentions products from Groups 3, 7 and 11, yet notes growers aren’t using them as “insurance” or an annual measure. He also hasn’t seen any growers opt out of needed fungicide applications as a cost-cutting measure in the wake of higher fertilizer or fuel costs: when crops need a fungicide, growers protect that investment.

“There are tank mixes and some multi-mode-of-action products that are premixed that work great,” says McColm. “Fungicides are a tool that can be used, although very few use them as ‘automatic.’ Some growers will plan to use a fungicide application if environmental conditions favour that application and they have had issues in the past.”

Ultimately, growers have to pay stricter attention to avoid white mould. Environmental conditions and varietal selection are important. McColm says a variety with high tolerance doesn’t guarantee the disease won’t be a problem. Growers must be mindful of environmental conditions, and use a fungicide if conditions are favourable.

The post Managing white mould in soybeans appeared first on Country Guide.

Waterhemp has also spread rapidly, with biotypes resistant to Groups 2, 4, 9, 14 and 27 now found in 18 counties in Ontario, up from 15 in 2022.

Those are troubling challenges for growers, including those planting the latest Roundup Xtend and E3 soybean technologies. The good news is there are still post-emergence choices for adequate, if not excellent weed control. However, those growing identity-preserved (IP) soybeans and Roundup Ready varieties face the prospect of just one option: the need for perfect or near-perfect pre-plant or pre-emergent control, especially of glyphosate-resistant Canada fleabane.

“If you go to IP soybean, you really have to control (Canada fleabane) — and this is also true of Roundup Ready — where you need to have 100 per cent control before the soybean comes out of the ground,” says Peter Sikkema, weed scientist at University of Guelph’s Ridgetown Campus. “We have nothing post-emergence to control glyphosate-resistant Canada fleabane in either IP or Roundup Ready soybean.”

Based on his studies, Sikkema found growers with IP and Roundup Ready crops could achieve 93 per cent control on average using Roundup + Eragon + metribuzin + Merge. Metribuzin is an active ingredient in products such as Bifecta, Boundary, Canopy PRO, Conquest, Sencor, Tricor and Triactor. In many of his studies, they achieved 100 per cent control, and plots stayed clean until harvest.

Perfect control needed

And Sikkema says 100 per cent is the objective.

“When I started … in the mid-1990s, among weed scientists at that time, if you had perfect weed control, some people would say you spent too much money on herbicides.” Ninety-five per cent control was considered good enough. In 2023, I’m rapidly gravitating to having perfect weed control so we don’t get any weed seeds returned to the soil.”

He says that can’t be underscored enough. If there is 100 per cent control and no weed seed return, there can be no selection for herbicide resistance because there is no “next generation” of seed to contaminate a field the following year.

Recent higher prices also underscore the importance of weed control. Sikkema refers to poor weed management as “leaving money on the table.”

“In the trials we’ve done, the average yield loss in soybean due to glyphosate-resistant Canada fleabane interference is 61 per cent in experiments conducted on farms in Ontario. In our most competitive environments, it’s up to 99 per cent. In soybean, the latest numbers I hear … some people are getting close to $20 per bushel. If you have 50 bushels per acre at $20, that’s $1,000 per acre but with a 61 per cent yield loss, you’re losing $610 per acre.”

The importance of managing fleabane is magnified because it grows as a winter and a summer annual. If it’s in a no-till operation and the weeds are up before soybean planting, it’s very competitive. Add waterhemp, another challenging weed species, and growers face a significant one-two punch in managing herbicide resistance. Since waterhemp is a summer annual weed that begins emerging in May and continues to germinate well into fall, the need for season-long control is imperative.

Think five years ahead

Sikkema says the need for timely herbicide applications and reducing weed seed returns to the soil requires switching from a reactive to a proactive approach. That may require a shift in thinking for many growers — from a one-year to a five-year plan.

“Whether you’re a corn, soybean or dry bean grower, regardless of the weed species on your farm, you should have a planned, two-pass weed control program and multiple herbicide modes of action in that program,” he adds. “The goal has to be zero weed seeds returned to the soil. It is really important to identify your weeds and knowing which species you have in each field. You have to adjust your weed management program based on the species composition in each field.”

As challenging as it may be to grow IP or Roundup Ready soybeans, the pressure is nonetheless different for those opting to plant Roundup Xtend and E3 soybean technologies. Although these traited varieties provide more weed management options, growers must be diligent in use of dicamba or 2,4-D because of the potential for off-target movement and injury to sensitive crops in adjacent fields. That’s where those five-year crop and weed management programs come in to build diversity, minimize selection intensity for additional herbicide-resistant weed biotypes and reduce the risk of damaging relations with neighbours.

“Farmers need to plan what crops they’re going to grow and their weed management program,” Sikkema says. “If they’re using a Group 2 or a Group 14 herbicide four or five times over a long-term program, they should try to reduce that and introduce more diversity. It’s not just ‘What am I going to do in 2023?’ It’s ‘If I do this in 2023, how will that impact what I do in 2024, ’25, ’26 and ’27?’”

It isn’t just the prospect of losing money to poorer weed management: it’s also facing the loss of tools which will increase the challenge of weed management even more in the future. 

– This article was originally published in the 2023 edition of the Soybean Guide.

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It was a decade ago that a company from the United Kingdom — Azotic Technologies — finalized the development of a biological seed treatment that would enable a corn plant to fix nitrogen in the root zone. The work began in 1960 at the University of Nottingham in England and continued until 1988 when researcher Edward Cocking discovered a bacterium in sugar cane — one of roughly 500 different bacterial strains — that could supply up to 50 per cent of a sugar cane plant’s nitrogen needs.

Ten years later, two companies have derived biological treatments, each with a unique mode of action which helps plants capture nitrogen from the atmosphere for a variety of crops including potatoes. Corteva Agriscience has brought Utrisha N, a foliar treatment, to the market while Syngenta has Envita, which is derived from Cocking’s research more than 30 years ago and can be applied either in-furrow or as a foliar treatment.

Utrisha N

The 2022 growing season was the first in this country for Utrisha N, with higher than expected uptake among corn growers in Eastern Canada and canola growers in Western Canada, according to Corteva. The company expects Utrisha N will also be used in cereals, soybeans and horticulture crops.

According to Mark Versluys, specialties business leader with Corteva Agriscience Canada, grower uptake and response have been positive.

“We’re still running through the trial data, but it looks very strong,” says Versluys. “Feedback has been extremely positive on user experience, including application. There was a strong reaction regarding biologicals in general and Utrisha N, in particular, on the survey which was sent out to growers. As well, there was a very high response rate relative to other non-biological surveys that have gone out. The expectation is for rapid growth in this segment going forward.”

Referred to as a nutrient efficiency biostimulant in company literature, Utrisha N enters the plant through the stomata in leaves. Once inside, its active ingredient — Methylobacterium symbioticum — colonizes and converts nitrogen gas from the air into ammonium, providing a constant supply of usable nitrogen to the plant.

In May 2022, Corteva Agriscience received certification from the Organic Materials Review Institute for the use of Utrisha N in organic farming in Canada. Versluys says he anticipates Utrisha N will have an excellent fit with potatoes since it’s an opportunity to supplement the nutrient needs of this high-value crop with a sustainable form of nitrogen. The 2022 growing season saw a number of Utrisha N trials for potatoes with high-profile growers and consultants. Anecdotal information referred to healthier looking, more robust plants in some situations.

“A plant with access to all of its nutritional needs will be more able to fend off pests, diseases and other environmental stressors,” says Versluys. “Since Utrisha N allows the plant to have access to nitrogen all season long, it would contribute to this state.

“It’s a fully supplemental source for the plant, allowing the fertility plan to meet its potential by eliminating having to pull nitrogen from a single source. Conventional nitrogen sources have limitations with respect to the prospect of volatilization or leaching.”

In addition to supplementing the supply of nitrogen to plants during the season, products such as Utrisha N could attract more attention as a way to address environmental concerns as the drive for sustainability becomes more prominent in agriculture. Company literature from Corteva states the use of the product carries no risk of leaching into water tables or releasing additional greenhouse gases.

The plan for Corteva is to have farmers use Utrisha N as a complementary product within existing fertility plans to maximize their potential. It is also the company’s first step into the biologicals space in Canada, with more entrants to come in the near future.

Envita

It has been a long journey for Envita from its arrival in Canada by way of Azotic Technologies to today. Like Corteva’s biologics entrant, it’s expected Envita’s highest uptake will be for corn in Eastern Canada and canola in Western Canada, although Syngenta says there’s been interest in its use for cereals, soybeans, pulses and potatoes as well. The technology also recently received approval for organic use in Canada.

“Envita is a perfect fit for Canadian growers,” says Nathan Klages, biological business manager for Syngenta Canada. “We continue to evaluate new biological products and will be adding to our portfolio in the coming years.”

The single rhizobial bacterium Cocking isolated in 1988 — Gluconacetobacter diazotrophicus — remains the active ingredient in Envita. According to Syngenta, the bacterium fixes nitrogen from the air soon after Envita is applied, providing an additional N source where and when it is needed the most for yield.

Cocking found G. diazotrophicus thrives in the intercellular (outer) environment of sugar cane, forming a symbiotic relationship with the plant. Azotic Technologies has now determined the bacterium also functions intracellularly — within the plant.

Klages states the response to test plots of Envita within the potato sector has been strong.

“Under irrigated and non-irrigated situations, we’ve seen very positive results during field-scale comparisons,” he says. “Field-applied nitrogen is not always plant-available due to environment or the weather, root development and the nitrogen cycle, so Envita helps fill that nitrogen gap.”

Field-scale trials conducted across Canada during 2020 and 2021 showed crops treated with Envita out-yielded untreated check plots approximately 80 per cent of the time. The product will be available from Syngenta for the 2023 growing season.

Klages considers N-fixing biological products a game changer for agriculture, and he says it’s something growers have been waiting for.

“Syngenta actively promotes best management practices and stewardship with growers, with a goal toward greater sustainability,” he says. “Envita provides an opportunity for more crops to be capable of fixing atmospheric nitrogen.”

Klages says he sees a need for Envita in regions like Manitoba and Ontario which are seeing increased calls for better nutrient management in soils, especially in areas where watercourses are nearby. He adds it could also be a tremendous benefit to potato producers in Prince Edward Island who are trying to reduce soil erosion while improving water quality.

Grower survey

A recent survey of roughly 800 Canadian producers revealed a majority believe their crops could benefit from alternative sources of nitrogen.

In the survey conducted by Corteva Agriscience, growers said they would consider using biostimulants and that they regarded biologicals as a viable, cost-effective and environmentally sensitive option to help their crop nutrient plans.

The survey also showed a level of confusion regarding biostimulants and differentiating between biologicals and micronutrients. Growers did express a desire to learn more about biologicals and how they work.

Specific results include:

• 78% of participants were concerned about nitrogen loss in their fertility program
• 95% said sustainability in their crop inputs is important
• 89% said they believe their crops would benefit from a supplemental source of nitrogen
• 80%+ would consider adding a biostimulant to their fertility plan
• 79% are using biologicals or biostimulant products or are interested in learning more about them

– This article was originally published in the 2023 edition of the Potato Guide.

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But no-till organic? In soybeans? That’s an entirely different level of thought processing, planning, monitoring and showing flexibility in adjusting to growing season conditions. For starters, there’s the three-year certification process necessary for organic production. 

Then, in an intriguing turn on weed management, learning to use cereal rye as a cover crop weed suppressant. That’s the subject of a three-year study by the Ontario Soil and Crop Improvement Association (Tier 2 project), funded by the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and the Canadian Agricultural Partnership.

OMAFRA field crops soil management specialist Jake Munroe led the 2019 to 2021 study with the help of OSCIA farmer co-operators. He came away with several recommendations and conclusions for those interested in exploring no-till organic soybean production. 

To start, it’s a system better-suited to established organic growers, not as a first step for transitioning from conventional/GMO-based crops to organic. Second — and perhaps most important — yields in the three years averaged 32 bushels per acre, 40 per cent lower than tillage-based organic production and conventional no-till (using herbicides).

“You can still be profitable with yields that aren’t as high, and if you are getting high yields, you’ll be that much more profitable in organic production,” Munroe says. 

He doesn’t want to discourage growers from trying, just ensuring they go into this knowing the facts. “The comparison should be made between standard 30-inch-row, tillage-based organic soybean production compared to this cover-crop-based organic no-till system.”

Lots of work in advance

Munroe has authored an online resource on OMAFRA’s Field Crop News website. The document details seeding the rye cover crop in late summer, gauging its viability as a weed suppressant, roller-crimping the crop the following spring and then planting soybeans. The full timeline consists of:

• Seeding cereal rye at 110 to 170 lbs./ac. in late August/early September.
• Monitoring its progress through fall to determine its overall production. If it’s too thin, till under before jointing. If conditions in spring are dry but the rye stand is reasonably strong, harvest it as grain or cut it for feed.
• By April to May, cereal rye can grow rapidly — as tall as six feet.
• Use a roller-crimper in late May to flatten the cover crop at 50 per cent anthesis (although that’s open to discussion).
• Plant/seed soybeans in late May to early June at populations of 250,000 to 300,000 seeds per acre to close canopy and maximize yield.
• Monitor the soybean seedlings as they emerge later in June.
• Ideally, the cereal rye mulch will suppress weeds until the soybean canopy shades out weeds.

Equipment

Munroe recommends planting or seeding equipment that can cut through thick plant residue. OMAFRA soybean specialist Horst Bohner helped Munroe, using a Kearney no-till planter with a three-quarter-inch wavy coulter that did a bit of tillage and cut through the mulch and the root balls of the rye. Munroe stresses that adequate down-pressure is needed to get the seed to depth consistently, along with closing wheels that will close the seed slot (the OMAFRA tests used a Dawn Gaugetine closing wheel).

He says it’s not that it can’t be achieved with regular planters, but organic growers may not want to make those modifications on a planter that’s mostly doing corn in a full-tillage setup. 

“That being said, this is a system that largely appeals to and has been adopted by organic growers, and most of them will have a conventional planter that’s not equipped for high-residue or no-till conditions. That’s the challenge of having that equipment or making modifications to a planter specifically for this system. A well-maintained no-till drill can be used to seed soybeans instead into standing rye ahead of crimping.”

The complexity of managing an organic no-till soybean crop benefits a grower who has a backup plan to answer the “what if” scenario of a thinner-than-desired cereal rye stand or a dry early summer. A heavy rye cover crop needs a lot of moisture, and in a drier-than-normal May and June, planting soybeans will prove a challenge.

“If you deplete that soil profile of moisture through a rye crop in a year where it’s very dry and you aren’t bailed out with timely rainfalls, that’s where you might see the biggest yield hit,” says Munroe, speaking from experience in one of the test years.

Greater flexibility

Aaron Bowman has learned the ins and outs of organic production and views no-till soybeans as an occasional cropping option. The livestock producer from Hampton, just east of Oshawa, raises beef cattle and markets it through the family’s on-farm store. Of the operation’s 350 acres, 240 are certified organic, featuring seven or eight crops in rotation, including three or four years of alfalfa, grain corn, forage corn, and oats, pea or sorghum as a cover.

Corn remains the main crop and June is the line in the soil for determining whether it’s planted in a given year. Bowman has a cultivator with an RTK-controlled electronic eye with a side shift that moves the row unit for the scuffler unit that kills weeds. The RTK capability also provides repeatability. But if they get back-to-back rain events and can’t get in to scuffle the first few weeds that get into the corn row, it’s done.

Although Bowman hasn’t grown organic soybeans with a rye cover in the past two years, he has started 2023 with three fields under rye. If soybean prices spike, he can adjust his plan in the spring.

“A lot of it comes down to how you prepare it, how you get it ready and when you terminate it,” says Bowman, who consulted several people on using rye as a cover, including Erin Silva at the University of Wisconsin. “Broadcasting rye seed has been a game changer and most people drill their rye … in my opinion, you’re leaving a space, and if you leave spaces, we all know that weeds will find them.”

Timing of crimping is the other concern in dealing with the rye cover crop. The first year Bowman worked with organic soybeans was 2016, which ended in disaster by his standards — they crimped too early. The rye started coming up and again and continued consuming all available moisture. The rye remained viable and goosenecked as it regrew. Thankfully, it was only nine acres but he wound up letting the cattle graze on it, then turned it under and planted sorghum. He returned to it in 2018, but not before consulting with Silva.

“She made it blatantly clear where I had messed up: I crimped too early,” says Bowman, who is also a Corteva seed dealer. “She said it needed to be at 100 per cent anthesis, getting to that milk stage where you start to see small seed. When you crimp it, it’ll stay down.”

His 2018 results were much better, crimping around June 6 to 7. He also uses a planter for soybeans into the rye cover, running 20-inch rows and doubling back to them on 10 inches. He plants 225,000 seeds per acre, and says the only drawback is the time required for the soybeans to canopy, which means giving up more sunlight.

“We all know that wasting sunlight on soybeans is not a good thing,” says Bowman. “I’m a firm believer that the planter puts the seed where it belongs, where you have a lot more control over depth, especially with our hydraulic downforce. It’s never riding over top, and I know for a fact it’s always cutting through and jamming it to the bottom of the trench. There might be an inch to an inch-and-a-half of residue that you have to compensate for and ensure you’re still planting at the depth and to moisture, because that rye is really pulling away huge amounts of moisture.”

The rye in rotation provides flexibility and an insurance plan. If the livestock operation needs more feed or grazeable acres, Bowman can always harvest the field mechanically, or “with four legs.” That’s the benefit of having livestock, where there’s less waste and it’s more forgiving in terms of using the mistakes to help the cattle.

The project was funded in part by the Ontario Ministry of Agriculture, Food and Rural Affairs through the Canadian Agricultural Partnership.

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Researchers and plant breeders have explored new methods to address diseases or pests, but these advances can have trouble gaining traction without translating to more bushels in the bin.

Matt Rundle is trying to shift the focus on performance by examining more of the physiological properties of plant growth in soybeans. He’s working with Hugh Earl, Dave Hooker and Istvan Rajcan from the University of Guelph and Horst Bohner of the Ontario Ministry of Agriculture, Food and Rural Affairs on a three-year project to measure critical variables during growth stages R2 to R5. He’s measuring in-season characteristics that aren’t standard, with the goal of determining how crop growth rate relates to final yield components such as pod numbers, seeds per pod and seed size.

The study is the basis for his master’s degree and is funded by OMAFRA and Grain Farmers of Ontario.

Better beans

Rundle is trying to quantify the effects of location and management on dry matter accumulation, yield and yield components. He’ll attempt to correlate crop growth rate at different times of the growing season with variation in final yield components across a variety of management practices.

“Some of the work may not directly correlate to a new agronomic practice that you can apply to increase farm revenue,” says Rundle, now a product placement scientist with Syngenta’s North American seeds development team. “That’s what the agronomic work is doing but some of this physiology work creates knowledge that we can build on for future practices or products we can bring to market.”

The R2 to R5 stages encompass flowering and determine the level at which that range is a determinant of yield, based on pod numbers, seeds per pod and seed size. Some of the traits he’s tracking include above-ground biomass, interception of incoming solar radiation into the canopy and greenness in the canopy.

The study uses a randomized complete block design at three sites — Woodstock, Maryhill and Elora — giving Rundle nine site years of data from three varieties and four replications per site. The three varieties were selected from the Ontario Soybean and Canola Committee trial summaries for their above-average performance and same days to maturity, approximately 2750 to 2775 crop heat units. Plots are planted to 15-inch rows, 160,000 seeds per acre with insecticide, fungicide and inoculant seed treatments. The sites are kept weed free with soil-applied and in-crop applications, and scouted for insects with spray applications as required.

‘The 100-bushel challenge’

The research began in 2021 and will continue through the 2023 growing season. Although it’s been dubbed “The 100-bushel challenge,” Rundle notes the 100-bushel mark has been eclipsed, and genetic yield potential continues to climb.

“To be honest, we may not get (to 100 bushels),” says Rundle. “But we wanted to shift the narrative away from the notion that if we don’t hit 100 bushels, we’ve failed. This is about these other pieces we’re considering.”

Rundle concedes most growers aren’t concerned with greenness in the canopy or radiation-use efficiency, but he wants to use the data to summarize the findings that could be used in a management practice, not as a means of discovering a “silver bullet.”

“It’s not this targeted approach to find one way to achieve higher yields, it’s understanding more about the plant which enables us to hit higher yields in the future. Beyond that, we’ve learned all of this from our crop growth rate measurements or canopy greenness or the radiation use efficiency, but there may be unanswered questions at the end. That’s the fun of it: this may create more opportunities for master’s students to look at this and follow it up.”

Confirming past studies

Despite conducting more than 700 soybean trials, Horst Bohner knows there’s an opportunity to learn more beyond the standard metrics he’s been studying for the past 20 years. This project isn’t about repeating aspects of his research or testing every foliar fungicide.

“I’m curious because we’ve often observed that inputs are not additive for soybeans like other crops,” says Bohner, soybean specialist with OMAFRA. “In other words, 1 + 1 does not equal 2 but rather 1 + 1 = 1. This is non-linear, where you’re determining whether you’re addressing the same shortcomings of yield potential. For example, a little nitrogen might be doing the same thing as early planting.”

In the first two years of the project, the average non-irrigated field response was 6.5 bu./ac. in high management over the untreated control. But is that a reflection of doing those things that are known to be “right” to get a 6.5 bu./ac. response? Or is that tied to the physiological factors associated with growth rates at R2 to R5?

“We’re not necessarily trying to focus on which inputs are economical at each site for this project,” Bohner says, citing soil-applied fertilizers with 100 pounds of actual N, twice per season as an example. “Ultimately, we’ve had some nice differences in yield with respect to different sites.”

Bohner says the three most commonly cited influences on yield are variety, good soil and weather (climate). It’s possible to have a 6.5-bushel response from enhanced soil test levels or a better N response during a dry year. He hopes Rundle’s work can help determine the fundamental differences between a plant that yields 100 bushels and one that yields 50.

“We need a couple of more years of data to tease out the details of what works best. The good news is that we have a lot more space upwards in the potential for soybeans compared to other crops like corn.”

The pot test

The opportunity to study the physiological factors in soybean production is of particular interest to Hugh Earl. In a separate component, also funded by the GFO and OMAFRA, Earl tried something he’s wanted to do for years. He’s growing the same variety in the same field at the same time, but growing it in pots in an adjoining irrigated plot, effectively eliminating water as a limiting factor. The responses he saw in 2022 were surprising: 78 bu./ac. in the field but 88 bu./ac. in the pots.

“Those plants in the pots had far more biomass and grew ‘leggy,’” says Earl, associate professor of crop physiology at the University of Guelph. “I honestly believe that if everything was perfect below ground, we’d be far above 100 bushels. But then the question is could you ever do that? Probably not — there’d be some fundamental limitations of the soil — maybe its ability to move water towards the roots fast enough.”

It’s the opportunity to study the plant physiology that’s intriguing: how were high-yielding plots different from low-yielding plots? Were there more plants per metre squared? Were there more pods per plant or seeds per pod or were the seeds larger?

“Which physiological component varies when you have big yield differences?” Earl asks. “In soybean, that’s almost always pod number. Sometimes seed size will come into it, especially with late-season stress. For every point in the season, you can determine how fast ‘this’ plot is growing, or how fast ‘that’ plot is growing. The growth rates are telling you what kind of photosynthetic rate it is at that time of the season and every yield component has a point in the season where growth rate is going to have the biggest effect.”

Based on that measurement, Earl contends pod numbers are determined between R3 and R5, and a high crop growth rate will determine the pod number. A little later in the season, the effect will be greater on the number of seeds in the pod, and on seed size much later.

“The idea is to look at all of these location years and treatments and say, ‘How do big yields compare to little yields in terms of which yield component is affected, and where in the season was that yield component determined?’”

The post Unlocking soybean yields appeared first on Country Guide.

The 2022 growing season was the first year for a project to study mid-season corn tissue sampling to determine whether it would boost yield. There has been past late-season tissue sampling to assess nutrient levels from the previous growing season, but this mid-season testing was to assess potential to boost the current crop’s yields.

“Interest was sparked in 2021 when some nutrient deficiencies related to zinc (Zn) were discovered at corn tassel (VT),” says Danny Jefferies, precision ag specialist with Deveron, based in Chatham, Ont. “The goal of this project is to be long-term, ultimately developing a protocol which delivers actionable insights resulting in yield and profitability increases for our clients.”

Deveron worked with four farmer collaborators across Ontario, and had support and partial funding from the Upper Thames Conservation Authority. They used precision tools available to the farmer participants, along with measurements from plant tissue analysis by A&L Laboratories Canada in London.

Four samples were collected from each farm, June 13 (V5), June 27 (V7), July 11 (V10) and August 24 (R4). The goal was to benchmark conditions earlier in the season and then track responses from later treatments to determine the best chance at targeting applications for optimum effect. It was especially important to understand corn nutrient uptake timing, and rates, partitioning and remobilization, keeping in mind that most uptake increases quickly after V6.

“We also wanted to be sure to have sampling around or just prior to VT timing to allow for evaluation of zinc uptake and perhaps capitalize on a sprayer pass already occurring with fungicide applications,” says Jefferies. “Ideally, if a budget was unlimited, additional samples and tracking over tighter intervals would be beneficial.”

The process

Samples were collected from two locations in each field, chosen based on yield potential. Jefferies says they used historical yield maps to select traditionally high-yielding areas, and then a low- to medium-yielding area. They deliberately avoided areas with poor yields resulting from environmental factors such as standing water or eroded knolls. The idea was to push low to medium areas into higher yields based on limiting factors based on nutrition rather than environment.

“We collected a baseline soil sample at the same time and location of our first tissue sample collection. This provided us a measure of background soil fertility at that location. We also did multiple collections at each site, including a tissue and a sap test collection.”

For the sap testing, they collected a sample from the lower leaves (older growth) and upper leaves (newer growth). Based on observations from the tissue test, they evaluated and made recommendations to the farmer clients, including choices for product applications. Then they evaluated the nutrient’s uptake, using additional post-application tissue and sap tests to find changes in those levels.

“The collaborators are top-end managers; all fields are well tiled, well managed for soil health and well fertilized with good background fertility,” says Jefferies. “The pursuit of micronutrients is further down the food chain and a potential ‘missing link’ in our 2022 data set will be the variable of moisture.”

He says generally, all site locations lacked moisture during July, with expected impacts on the corn’s nutrient uptake.

Another part of the project — which may need a more in-depth examination — relates to the choice of foliar products. There are plenty of foliar nutrient solutions available, including chelated and fulvic acids. Some of the collaborators also apply tank mixes with different adjuvants. Jefferies believes there are differences in how products perform in terms of plant uptake and the responses he saw in the tissue and sap tests.

Cleanliness is important

Jefferies says they took great lengths to ensure samples were taken in the cleanest conditions, avoiding contamination from dust or soil on the tissues or contact with fertilizers, salts or grease.

“We also made sure to sample after applications to make sure we weren’t in the field immediately or shortly after the product was applied. It was important not to sample when there was still moisture on the leaves, as this could influence the sap test results. We took care to store samples cool and transport them in a cooler — quick delivery to the laboratory was also important.”

It’s been suggested that mid-season tissue tests offer a greater return on investment for higher-value crops such as potatoes, but Jefferies maintains there is certainly value to tissue testing in cash crops. The key is to conduct the sampling strategically and economically — to “fry the big fish first” and ensure they have the background fertility well managed, then sample in multiple locations using satellite imagery or historical yield data.

The testing in this program assessed the entire spectrum of macro- and micronutrients within the leaf. The sap test also analyzed sugars, pH and nitrogen conversion efficiency (NCE), which illustrates the plant’s efficiency in converting nitrogen to usable forms like amino acids and proteins. They also observed how certain nutrients behave once in the plant tissue.

“Boron, even though it’s mobile within the soil profile, is immobile within the plant,” explains Jefferies. “We saw an uptick in boron levels post-application, but sampling a couple of weeks later, our levels were back down as the nutrient didn’t move to the new growth. This really illustrated the importance of hitting an ideal window for timing when the nutrient is most in need.”

Environmental spinoffs

The capability and efficiency of plants to use available or applied nutrients is a growing concern outside of agriculture because of environmental effects, but research into doing more with less also offers farmers the opportunity to save on expensive fertilizer and other inputs.

The Upper Thames River Conservation Authority (UTRCA) has been working with Deveron staff for several years, examining the impact of cover crops from environmental, economic and agronomic perspectives. The environmental impact was reason for the UTRCA’s interest for this tissue-testing project.

“As we promote practices, we need to also consider the impact to the whole farming operation,” says Tatianna Lozier, stewardship services co-ordinator with the UTRCA. “The economics of soil health, water quality or climate change practices continue to be at the forefront of conversations these days. Deveron staff have provided valuable insight into the type of data we should collect to answer farmer-led questions about their fields and have been invaluable in analyzing the data.”

The authority has participated in past studies investigating potential nutrient loss from stream vegetation or cover crops. Tile drainage and surface runoff, especially of phosphorus, have always been of concern for the UTRCA. For this project, they included tissue sampling based on recommendations from Deveron staff to provide potential insight on differences in yields with or without cover crops.

Lozier says this kind of research offers the opportunity for understanding from all sides — stewardship, farming and research/service providers.

“Our stewardship staff will continue to learn and expand our knowledge of precision practices, but ultimately we rely on partnerships with those who have expertise outside of our organization. Working in partnership with companies like Deveron allows the opportunity for a number of different perspectives on an issue.”

The project is slated to continue in 2023, with several challenges. Lozier says they’re looking for more collaborators, but Jefferies says tissue testing is labour-, time- and equipment-intensive, and labour availability is at an all-time low. They also need further validation that their recommendations are leading to higher yields, which could help convince growers of the value of testing and specific nutrient applications.

Other resources:

• Studying the Economics of Cover Crops (UTRCA/YouTube)

The post Sampling plant tissue for a mid-season boost appeared first on Country Guide.

Harvest weed seed control is the latest development in the battle against weeds, with early adapters working with different designs and seeing success. The concept employs seed mills attached to the rear of the combine, gathering weed seeds during harvest and crushing them to prevent or reduce germination. Currently, there are four designs: the integrated Harrington Seed Destructor (iHSD), the Seed Terminator and the WeedHOG, all of which are Australian, and the Redekop Seed Control Unit, built in Saskatchewan.

In 2011, researchers with Agriculture and Agri-Food Canada (AAFC) created a vine crusher to help control European corn borer (ECB) in potatoes. Two metal rollers were attached to a motor and placed on the back of a potato harvester to gather and crush the vines, killing ECB larvae. But winged adults could fly to another field, so to optimize the value of a vine crusher, every farmer would have to have one.

Ten years later, AAFC-Charlottetown researcher Andrew McKenzie-Gopsill re-examined the crusher and adapted it to gather weed seeds in potatoes and damage them to reduce germination. It worked: in 2021, he tested the unit, gathering seeds of lamb’s quarters, a common species on Prince Edward Island. The first set of seeds was fed through the crusher, collected and germinated in a petri dish. The second set was fed through the unit, gathered and germinated in soil in a greenhouse and the third was sent through with potato biomass and then grown out in greenhouse soil.

“When we did the petri plate under controlled conditions, we saw some of the lamb’s quarter seed, and even though there’s only half of the seed and it has either a hypocotyl or a radical, it germinated,” McKenzie-Gopsill says. “It was only in the petri plates but when we go to the field soil, those things that would potentially germinate when they only have a primordial shoot or root — they’ll die and they won’t emerge from the soil.”

Whether there’s a definite percentage of the seed that has to be damaged to prevent germination has yet to be determined. The results for field-based experiments using the vine crusher were unavailable early in 2023, but McKenzie-Gopsill liked what he saw last fall.

“We were able to harvest our potatoes and see material moving through the vine crusher, and it looked like it was doing what it was supposed to be doing. We collected some lamb’s quarters so we threshed those and we’re doing a germ test on those in the growth chamber. Then we collected soil cores to see if there’s any effect on the seed bank.”

One concern was whether they might be seed scarification that encouraged or increased germination. However, in testing in the greenhouse with the material that moved through the harvester, they had upwards of 90 per cent control with some of the larger seeds.

“If we increase germination following harvest, that’s good for a potato field, where we’re getting a small drawdown on the seed bank because any of those emerging annuals will be winterkilled out,” McKenzie-Gopsill says. “A week after we harvested, I went out to look at what we had and could see a bunch of common chickweed seedlings had emerged just in our rows that we’d harvested with the vine crusher.”

They found an increase in emergence and compared that to rows where the vine crusher wasn’t used, which had little or no weed emergence. There were nearly 200 chickweed seedlings per square metre at high density, but they should be winterkilled. He adds that chickweed can overwinter, but that’s usually with well-established plants.

As effective and inexpensive (at $10,000) a design as the vine crusher is, it’s best-suited to horticulture crops like potatoes, not at the back of a combine for corn or soybeans.

Test in the West

Corn, soy and wheat growers in Ontario and Quebec must manage resistant Canada fleabane and waterhemp, and in the West, growers are grappling with resistant wild oat and kochia.

Breanne Tidemann has been working with harvest weed control systems since 2014 when she started on her PhD and worked with a tow-behind version of the Harrington Seed Destructor, now available as a fully integrated system for combines. She’s also worked with preliminary prototypes of the Redekop Seed Control Unit.

“I’ve seen greater than 95 per cent of weed seed control of any of the weeds that go into the unit,” says Tidemann, a researcher at AAFC in Lacombe, Alta. “Anything that’s in the chaff and goes through the mill, it will control greater than 95 per cent of those weeds. The trick is actually getting it into the mill.”

Wild oat is one of Western Canada’s main problem weeds, and drops a significant number of its seeds before harvest, so the numbers are less effective. But of the 25 to 30 per cent seed retained, she’s still seeing 95 per cent control. Much of the efficacy in damaging the seed depends on the weed biology and stature, the accompanying crop and the number of modes of action to which the weeds are resistant.

“Weeds that are short to the ground and thistles or dandelion that float through the air are harder to get through the combine,” Tidemann says. “I originally thought wild oat has to be a lot easier to control in the mill than kochia because it’s such a small seed. I did a study with the Seed Destructor stationary, and I had kochia, green foxtail, volunteer canola, wild oat and I even put through peas, just as a large seed. With every single one, I had greater than 95 per cent control.”

Generally, seed size doesn’t seem to have as large an impact as the weed biology and when it’s maturing compared to the crop. Tidemann also tested volunteer canola seed, sieved it and separated it into five different thousand-kernel weights from 2.2 grams per thousand seeds to 5.8, and found a negligible increase in control with larger compared to smaller seed.

Can the weeds adapt?

While helpful, crushing, cutting or physical damage will not prevent weeds from evolving.

“I would never say that weeds can’t respond to any kind of weed control,” Tidemann says. “It doesn’t matter what it is, they will find a way, because it’s a selection pressure — it’s what evolution does.”

Researchers expect weeds to respond to damage by shifting their biology to drop their seeds earlier so they’re down before harvest, or to select for more prostrate forms making it harder to get into the combine. In Australia, where they’ve been using these control methods for 10 to 15 years, they’ve started seeing wild radish and annual ryegrass adapt.

“It’s why I would encourage using one before it becomes a last resort to manage resistant weeds,” Tidemann says. “If you have two effective (chemical) modes of action, it’s harder to develop resistance to either of them. With herbicides plus harvest weed seed control, it’ll be harder for weeds to develop resistance to both and become problematic. You can use it strategically to manage where those weed problems are.”

Tidemann says harvest weed seed control systems should be part of an integrated approach, with a combination of chemical, physical and cultural means increasing the chances of success.

Tidemann adds that manufacturers have been listening to growers and adjusting the units according to their needs. Since rocks can be a problem, some are mounting rock traps on the unit or magnetic strips to pick up bits of metal in the field.

The current integrated systems can run upwards of $100,000, but Tidemann says it’s the cost per acre that’s important. A grower she knows runs a Seed Terminator on four of his combines and factors his interest, financing, fuel and repairs as part of the operating costs.

“He has it broken down based on his 4,000 (owned) acres and it costs him $6.50 per acre. It started higher but based on what he’s spent and how many years he’s used it and the repairs, it’s down from $10 when he was first using it.” 

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