For more than a decade, India has allowed Canada to treat pulse shipments for pests after shipping rather than before. But that may come to an end next month.
The fumigation of pulse pests requires the use of methyl bromide, a pesticide that Canada is trying to phase out because of concerns it depletes the ozone layer. It also doesn't work well in Canada's colder temperatures, leaving pulse producers with few options.
The stakes for the country's estimated 12,000 pulse farms are high. Canada shipped $1.5 billion worth of peas and lentils to India in 2015, accounting for about a third of all pulse exports.
"That's why we're very concerned," said Gordon Bacon, CEO of Pulse Canada.
Bacon said the federal government submitted documents to India in December pressing its case that the risks of Canadian pulse crops carrying pests is minimal because of the winter climate.
"India's message has become much more firm in terms of what their intention is at the end of March, which is why we're much more concerned now," he said.
Pulse producers are now eagerly waiting for a response, with an answer possibly coming in days. But shipments are already being disrupted, Bacon said, with at least one shipping firm refusing to take pulses this past Monday because of the uncertainty.
"It's hugely problematic for the industry when there's no clarity on what the policy will be," said Bacon.
The Indian government could not be reached for comment. But a notice issued by the India Pulses and Grains Association summarized a presentation that the Indian government made last month.
According to the notice, an Indian government official said methyl bromide is the only effective treatment against pulse pests, Indian exporters follow requirements of other countries and importers should do the same, and India shouldn't bear the risks to the ozone layer alone.
The association's notice said the government official also outlined potential alternatives, including the possibility of countries submitting data proving that other treatments are equally effective, a system-wide preventative approach assessed by Indian officials, or cargo pre-inspection. | READ MORE
By using a clever combination of two inexpensive additives to the spray, the researchers found they can drastically cut down on the amount of liquid that bounces off. The findings appear in the journal Nature Communications, in a paper by associate professor of mechanical engineering Kripa Varanasi, graduate student Maher Damak, research scientist Seyed Reza Mahmoudi, and former postdoc Md Nasim Hyder.
Previous attempts to reduce this droplet bounce rate have relied on additives such as surfactants, soaplike chemicals that reduce the surface tension of the droplets and cause them to spread more. But tests have shown that this provides only a small improvement; the speedy droplets bounce off while the surface tension is still changing, and the surfactants cause the spray to form smaller droplets that are more easily blown away. | READ MORE
Research leader Professor Neena Mitter said BioClay – an environmentally sustainable alternative to chemicals and pesticides – could be a game-changer for crop protection.
“Our disruptive research involves a spray of nano-sized degradable clay used to release double-stranded RNA, that protects plants from specific disease-causing pathogens,” she says.
The research, by scientists from the Queensland Alliance for Agriculture and Food Innovation (QAAFI) and UQ’s Australian Institute for Bioengineering and Nanotechnology (AIBN) is published in Nature Plants.
Professor Mitter said the technology reduced the use of pesticides without altering the genome of the plants.
Once BioClay is applied, the plant ‘thinks’ it is being attacked by a disease or pest insect and responds by protecting itself from the targeted pest or disease.
“A single spray of BioClay protects the plant and then degrades, reducing the risk to the environment or human health.”
She said BioClay met consumer demands for sustainable crop protection and residue-free produce.
FMC of Canada has announced a new expanded label for Authority 480 herbicide. The new label features more registered weeds and additional crops, according to a press release.
The weeds include eastern black nightshade, a particularly troublesome weed for identity preserved (IP) soybeans, and common waterhemp – the newest glyphosate-resistant weed in Eastern Canada. There are 13 weeds on the new expanded label, such as red root pigweed, lamb’s-quarters, wild buckwheat, eastern black nightshade, common waterhemp, yellow woodsorrel, common groundsel, cleavers (suppression), Powell pigweed and common purslane.
Authority offers a new group 14 weed control option for group 2 and glyphosate resistant weeds.
Several new specialty horticulture crops have also been added to the Authority herbicide label, including chickpeas, field pea, flax and sunflowers.
SDS is caused by Fusarium virguliforme. This fungal pathogen overwinters on crop residue and is occurring more frequently in fields across Ontario. Difficult to identify and often misdiagnosed, the disease results in average annual yield loss of about 20 per cent, but can cause losses of up to 60 per cent in a growing season, according to a press release from Bayer. To date, there have been no seed treatment solutions available for SDS in Canada.
ILeVO has activity on the Fusarium virguliforme fungus. The company says the effectiveness of the product has been demonstrated through field trials in the U.S. and Canada over the past five years, including third-party trials with OMAFRA and the University of Guelph.
A feature unique to ILeVO which signals a successful application is the “halo effect,” which is often visible on the edges of the cotyledons of a treated plant.
For more information regarding ILeVO, growers are encouraged to talk to their local seed companies and retailers or visit cropscience.bayer.ca/ILeVO.
DuPont and Monsanto will offer DuPont Lumivia insecticide seed treatment under the Acceleron brand in Eastern Canada for the 2017 sales season.
Lumivia insecticide seed treatment, part of the DuPont Lumigen seed sense portfolio, is the first insecticide seed treatment technology in Canada using chlorantraniliprole, a reduced-risk active ingredient that will give growers a tool to help control damage caused by a broad spectrum of pests.
Lumivia is a premium insecticide seed treatment that works systemically to translocate the active ingredient from the seed to the roots and developing stalk and leaves throughout seedling development. It delivers protection against key early season pests including wireworm, seed corn maggot (suppression only), black cutworms and armyworm that can cause devastating damage to a corn crop. According to DuPont, Lumivia insecticide seed treatment provides immediate and long-lasting protection of corn seeds and seedlings, which translates to uniform, healthy stands and increased yield potential through improved early season vigor.
Lumivia is available on DEKALB brand corn seed for the 2017 growing season as part of the Acceleron Seed Applied Solutions offerings in Eastern Canada.
"Healthy soil and crop nutrition are essential to crop production in Saskatchewan. The application of fertilizer using the 4R Nutrient Stewardship will help farmers continue to improve efficiency and grow more food," said Lyle Stewart, minister of agriculture, in a press release.
The alliance will strengthen existing environmental stewardship by helping farmers to adopt science-based fertilizer application practices using 4R Nutrient Stewardship. This partnership will create awareness programs, enable collaboration with farmers in the province and implement communication strategies on sustainable best management practices, 4R demonstration farms, and web-based training materials, according to the release.
Hormesis refers to an organism’s response to a stressor, where a low dose of the stressor causes a stimulating effect, like increased reproduction, and a high dose is very damaging or lethal. In the case of an insect, stressors could include things like insecticides, temperatures outside of the insect’s comfort range, insufficient food, and insufficient oxygen. But hormetic responses are not limited to insects. They have been observed in many, many organisms, ranging from microbes and plants to humans.
How hormesis actually works isn’t completely understood. “Probably the most commonly cited general theory is the idea of overcompensation. Systems that affect growth and reproduction [in insects and other organisms] are self-regulating and work on feedback mechanisms. So any sort of disturbance to those processes can result in the system trying to correct and overcompensate for it,” explains Chris Cutler, an associate professor with the department of environmental sciences in Dalhousie University’s faculty of agriculture.
For instance, let’s say an insect is exposed to a low dose of a poison that causes its reproductive system to go slightly out of whack. According to the overcompensation theory, its reproductive system will attempt to counteract the problem but will temporarily overshoot its response, leading to higher reproduction. “In a general sense, I think that is kind of how hormesis operates, but we still have a lot of the nuts and bolts to figure out,” Cutler says.
He explains that hormetic responses have evolved over millions of years as mechanisms for organisms to deal with low amounts of stress. So hormesis has always been around. However, it’s only recently that scientists have been identifying such responses as an actual phenomenon. “I think in the past, researchers would often look at [a hormetic] result and say ‘that’s weird’ or ‘that’s an outlier,’ and not really have a word to describe it. Those types of papers have gotten lost in the literature decades ago, but you can find them if you look hard enough,” he notes.
“We’ve documented incidents of hormesis in all sorts of insects, dozens of species across many different families and orders of insects, exposed to many different types of stress, whether it’s an insecticide stress, nutritional stress, temperature stress, radiation stress. So hormesis occurs widely and the concept is now pretty well accepted by researchers, and people are really starting to catch on to the idea.”
Cutler began his research on hormesis completely by accident. “I did my PhD research at the University of Guelph and was working with the Colorado potato beetle. In one of my experiments with an insect growth regulator, which is a more selective or more friendly type of insecticide, I was exposing eggs to the insecticide. I was expecting deleterious effects, like smaller eggs, eggs that wouldn’t hatch, and that type of thing. But in one experiment, I saw that at the low dose the survival and weight of the larvae were higher than in the control. At first I thought I’d got the concentrations mixed up or something. So I repeated the experiment a couple of times and got the same result. And I stumbled on this idea of hormesis, which at that time [about a decade ago] had not garnered much attention at all in insect circles.”
At present, the hormesis research at Cutler’s lab focuses mainly on insecticide-induced responses of various insects to various insecticides. “We’ve been using green peach aphid as a model. It is a widespread insect pest occurring all over the world, attacking lots of different crops, and insecticide resistance is a big problem in that insect,” he notes.
For example, he and his lab have been looking at how this aphid responds to imidacloprid, a commonly used neonicotinoid sold under various trade names, such as Admire. Their research shows that when the aphid is exposed to low doses of imidacloprid, the aphid’s reproductive output goes way up. Cutler says, “We’ve shown this in laboratory and greenhouse experiments where, after a few weeks, the population of the aphids on a plant can double due to exposure to the insecticide that is supposed to kill them.”
In a field situation, many different factors can lead to less-than-lethal doses of insecticide. “Insecticides break down over time. Sunlight will break them down. They are subject to microbial degradation. They are subject to wash-off by the rain. Also, drift can occur, so you may be trying to apply a high dose but the wind takes it so you get a low dose on the plant. And you have canopy effects when you spray so you don’t get as high a dose under the leaves or further down the plant,” Cutler explains.
“So inevitably you’re going to get insects that are exposed to these sublethal doses. And some of these low doses could be hormetic.”
Cutler sees many possible implications of hormesis for agriculture. One obvious one is that insecticide-induced hormesis could make a pest problem even worse by causing pest resurgences and secondary pest outbreaks. Pest resurgence is when the population of an insecticide-treated pest increases rapidly to even higher numbers than before the insecticide was applied. A secondary pest outbreak refers to a rapid population increase in a pest species that had been less important than the target species until the insecticide was applied.
Pest resurgences and outbreaks are often assumed to be due to the harmful effects of the insecticide on the pest’s natural enemies (the predators and parasitoids that attack it). But that assumption isn’t necessarily correct in all cases. Cutler explains, “There have been experiments that have excluded that possibility and shown the outbreak in the field – whether it’s due to aphids or thrips or leafhoppers – is directly due to stimulation from the insecticide.”
The degree to which insecticide-induced hormesis is contributing to pest resurgences and outbreaks in agricultural fields is not yet known. However, it has been documented in many field situations.
Insecticide-induced pest resurgences and outbreaks could clearly have serious impacts on susceptible crops, and could prompt farmers to apply more insecticides, raising their input costs and increasing the risks of insecticide resistance and negative impacts on the environment.
On the other hand, hormesis has positive implications for businesses that rear insects. “Insect rearing is a billion-dollar industry. Insects are reared for a lot of different purposes – for use in research, food for pets, food for people. Honeybees are reared for honey and pollination,” Cutler notes. “I think we can probably harness some of these hormetic principles for rearing these beneficial insects. It has been shown, for instance, that when you are rearing insects like Caribbean fruit flies for sterile insect release (SIR) programs, if you deprive them of oxygen for an hour, that mild stress can prime them to become better at finding mates, become better at emerging, have lower mortality and longer life spans. So this type of preconditioning hormesis can improve the performance of those insects later in life.”
In his current research, Cutler is delving into a number of different aspects of insecticide-induced hormesis, with the help of funding from the Natural Sciences and Engineering Research Council of Canada.
“One of the things we’re doing is looking at this idea of priming, so can mild exposure to one stress condition the insect to deal [more effectively] with subsequent stresses later in life or in subsequent generations? We’re looking at that in aphids.”
Cutler and his lab are also examining the possibility that hormesis may be contributing to insecticide resistance. “We’re looking at a couple of different angles there. We want to see if exposures to low doses of insecticide that may cause hormesis also induce the insect to produce more detoxification enzymes. When you and I or insects are exposed to poisons, we have enzymes that break down those poisons. So, if the insect is exposed to mild doses of insecticide, do we see more of those enzymes?” he says.
“[Another insecticide resistance angle] we’re looking at is whether exposure to mild doses of insecticide can increase mutations in insects. One of the main causes for mutations in organisms is stress. So we want to see if, for instance, hormetic stress that can cause increases in reproduction can also cause increases in mutations in insects such as aphids, and can some of these mutations be for insecticide resistance?”
Cutler is also investigating insecticide-induced hormesis in bees. He does a lot of research on bees and pesticides, so he’s well aware that pesticides are an important risk factor for bees. But he wondered whether insecticide-induced hormesis might occur in bees since it has been found in so many other insects. He recently published a paper identifying evidence in the literature that low doses of insecticide stimulate longevity, learning and memory of bees. Now he’ll be pursuing that idea in his own experiments.
What you can do
Although there is still much to learn about hormesis, especially under field conditions, Cutler offers a few suggestions for practices that could help reduce the risk of insecticide-induced hormesis on your farm.
One practice is to keep an eye on the pest population after pesticide applications. “I suspect that rapidly reproducing pests like aphids, leafhoppers and mites are more prone to outbreaks and resurgences from hormesis, although this has yet to be tested. This might be particularly true for insecticides that degrade to sublethal concentrations more quickly or for systemic insecticides (seed treatments) that work against early season pests but will be at sublethal amounts for most insects after a few weeks.”
Second, minimize drift and ensure good plant coverage when spraying insecticides. “This will minimize exposure of the pests to sublethal concentrations that might induce hormetic responses to stimulate their population growth.”
And third, avoid cutting insecticide rates below those recommended on the label. “As many growers will know, cutting rates is usually problematic because it can ‘encourage’ development of insecticide resistance while increasing the chances of suboptimal pest control. At the same time, exposure to these lower sublethal concentrations could stimulate reproduction of certain pests, possibly creating a double-whammy for the grower.”
The technology is incredibly, and increasingly, valuable to Eastern Canadian growers, where 2,035,000 of the total 2,295,000 acres of corn were planted to Bt hybrids in 2015. But the ever-present risk of the development of insect resistance to the technology is keeping the industry on its toes.
While resistance hasn’t yet developed in European corn borer (ECB) populations in North America, reduced susceptibility has been noted in some populations of corn rootworm, according to Jocelyn Smith, a research associate in field crop pest management at the University of Guelph’s Ridgetown Campus.
But resistance can be delayed with proper management. In Canada, stewardship of Bt technology takes the form of insect resistance management (IRM) plans, which chiefly involve maintaining refuges to delay the development of resistant insect populations.
Stewardship also entails rotation of traits in the field, as well as the use of stacked traits.
“The most important thing we can do with this issue is educate growers more about the risks they’re taking if they continuously use traits for rootworm,” Smith says. “Their sheer numbers and biology give them advantage.”
This is a message familiar to Eastern Canadian corn producers, and they’ve taken it to heart. The Canadian Corn Pest Coalition (CCPC) – made up of academics (such as University of Guelph researchers), the Canadian Food Inspection Agency (CFIA), the provincial ministries of agriculture, and industry representatives – has been conducting surveys on insect resistance management compliance since the late 1990s.
Until 2012, those surveys were conducted in alternating years with CFIA IRM compliance surveys, but that year, stewardship compliance rates were so high CFIA discontinued them unless “in future, industry practice shifts from using blended refuge.”
But the CCPC’s bi-annual survey continues. “The increase in compliance with refuge area requirements from 2013 to 2015 occurred in all three provinces and now stands at 91 per cent in Ontario, 90 per cent in Quebec and 91 per cent in Manitoba,” the 2015 report concluded.
According to the same report, compliance tended to be higher in the 35 to 44 age category, but lower among producers who believed stewardship requirements to be “only somewhat important.” In addition, the report indicates awareness of stewardship requirements has declined since 2013, particularly in Ontario; compliance was also lower among those who believed they did not understand requirements.
More education needed
Cindy Pearson, national manager of the CFIA’s Plant Biosafety Office, says the onus is on companies marketing Bt products to educate producers regarding the need for delaying resistance and how refuges work.
“IRM plans are the responsibility of the company to whom the Bt corn product has been authorized, and CFIA receives specific reports from companies that
detail their various activities on that front,” Pearson says.
The survey notes refuge-in-a-bag (RIB) hybrids, which contain the required percentage of refuge seed, resulted in significantly higher compliance rates after their market introduction several years ago. The market has also changed with the introduction of stacked hybrids with multiple Bt traits or modes of action against the insect pests.
“There are currently three traits available for corn rootworm control,” she says. “Where we have growers with long-term use of two of those traits on their own (not in a stacked product), we’ve started to
notice some shifts in susceptibility when we test those populations in the lab.”
This doesn’t necessarily mean producers can see resistance developing in the field, but it’s still a red flag.
“We need to focus on informing continuous corn growers that the three-year limit is important,” Smith says. “We may have had a situation where a grower has used a single trait for years and it’s compromised, so then when they use the stack there’s only one viable trait remaining against the pest.”
Smith also emphasizes monitoring as a key aspect of stewardship. “If you are growing corn on corn, scout your corn late in the season and if there’s less than one beetle per plant you might be able to get away without using transgenics,” she says. “You might be able to hold off on using some of the technology in the following year.”
Smith also recommends rotating management options — in other words, soil insecticides and Bt traits.
“And again in season, keep an eye on the pest situation in the crop. For ECB and rootworm, you need to monitor whether they are being controlled by the Bt hybrids or not. If they are not, you need to notify the CCPC and the trait provider,” she says.
As long as they use Bt technology, producers are on notice to use it well. Resistance is in nobody’s interest except the insects.
In the past six decades since these discoveries, weed scientists have documented more than 250 weed species with some form of herbicide resistance. These span 23 of the known 26 herbicide modes of action and impact 86 different crops across 66 different countries. As a result, the cost of weed control across the nation’s crop fields has tripled in recent years as growers are being forced to employ more herbicides per season, increase application frequency, and spend more on fuel costs to achieve some measure of control. | READ MORE
Bayer says it is paying Monsanto shareholders $128 per share, which represents a 44 per cent premium over Monsanto's closing price on May 9, the day before a proposed deal was announced.
The deal is subject to approval by Monsanto shareholders and anti-trust regulators. Bayer expects the deal to close by the end of 2017. | READ MORE
Unfortunately weather conditions around the time of application can be quite variable and can influence a herbicide's effectiveness. Let's go through "top tips" to make the most of this application window.
- Choose the most effective products, rate and tank-mixes for the perennial weed that you are targeting. Table 1 outlines what public researchers in Ontario have found to be most effective at controlling perennial plants in the fall.
- Apply when air temperatures are above 8 C for a minimum of two hours after application. This is best accomplished by applying during late morning or mid-day so that the targeted plant is taking up glyphosate during the heat of the day.
- After a frost event, wait two to three days before evaluating weed growth and if the target plants look fine and air temperatures are above 8 C then resume applications. For example, milkweed is very sensitive to frost. Figure 2 shows a milkweed plant three days after an evening where the air temperature reached a low of -3 C. It would not make sense to apply glyphosate on a weed species in that state since its leaves are unlikely to absorb any herbicide. Alternatively, dandelion and wild carrot were not affected by the same frost event (Figure 3 and 4) and one could resume fall applications to those species based on the condition of their leaves.
- Wait a minimum of 72 hours after application to perennial weeds if you want to till the soil. The longer that you can wait after application before making a tillage pass, the more the herbicide will translocate within the plant and do a more effective job controlling the species.
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National Invasive Species ForumTue Feb 28, 2017
AgExpoWed Mar 01, 2017
Central Ontario Agriculture Conference Fri Mar 03, 2017
National Farmers Union - Ontario ConventionFri Mar 03, 2017
Re-Tooling the Diagnostic Toolbox Soils and Crops 2017Mon Mar 06, 2017