A seed treatment is a vital and effective product, so long as it stays on the seeds where it can do its work. When it is released into the surrounding environment, however, it can cause significant political and environmental concern.
With proposed limitations and even all-out bans on the horizon, we could say the future of seed treatments has never been so uncertain. Although changes are coming down the pipeline (like the new mitigation measures for the neonicotinoids clothiandin and thiamethoxam), what won’t change is the fact that seed treatments are a very important tool in the grower toolbox.
The federal government has proposed tighter restrictions around the two insecticides: clothianidin and thiamethoxam.Under proposed changes, the product will be banned from some uses such as orchard trees or strawberry patches, and restrictions are on the way for other uses such as on berries and legumes. New measures will also require new labelling for seed treatments."Scientific evidence shows that with the proposed restrictions applied, the use of clothianidin and thiamethoxam does not present an unacceptable risk to bees," says Margherita Conti, an official with Health Canada's pest management regulatory agency. | READ MORE
With the 2017 growing season upon us, here’s a look at the latest seed treatments, foliar fungicides and label updates. Product information is provided to Top Crop Manager by the manufacturers.
Guelph, ON – Bayer has announced the launch of Trilex EverGol SHIELD fungicide and insecticide seed treatment, in a convenient package that offers complete disease and insect protection against the expanding presence of pea leaf weevil and wireworms for pulse growers in Western Canada. Trilex EverGol SHIELD is ideal for on-farm treating or for smaller batches towards the end of the treating season, and combines penflufen (Group 7), trifloxystrobin (Group 11) and metalaxyl (Group 4) with Stress Shield insecticide seed treatment (Group 4) that together provide exceptional seed- and soilborne disease protection against Rhizoctonia, Ascochyta, Pythium, Fusarium and Botrytis. Trilex EverGol SHIELD offers exceptional germination when compared to untreated seed, helping to promote a high-performing root system that supports optimal access to water and nutrients in the development phase. The concentrated formulation allows growers the flexibility to decrease water volume when adding Stress Shield, micronutrients and/or inoculants. This extra control allows for an optimized application volume and uniform coverage, which helps prevent product overload, allows for low seed moisture content and makes for easier flow through equipment. For more information visit cropscience.bayer.ca/TrilexEverGolSHIELD.
Guelph, ON – Bayer has announced that their ILeVO seed treatment is now approved for use in soybeans with the additional label claim of nematode suppression. Originally released as the first seed treatment available for soybean growers to protect against sudden death syndrome (SDS), the expansion provides growers with another valuable tool in suppressing soybean cyst nematodes (SCN) and root lesion nematodes. SCN in particular is difficult to see and diagnose, and can reduce soybean yields up to 30 per cent even without visual symptoms. Populations of SCN are on the rise, and even resistant varieties of soybeans are becoming more susceptible. In Ontario, where SCN is more widespread, estimated losses due to SCN range from $10-30 million annually. In 2015 and 2016, Ontario field trials demonstrated that ILeVO offered an average yield benefit of 3.6 bu/acre in nematode pressure areas. This is further supported by 338 variety locations run by universities from 2011-2016 in the United States and Canada, which showed a yield benefit of 4.7 bu/acre over non ILeVO treatments. For more information visit cropscience.bayer.ca/ILeVO.
All plants need nitrogen. While healthy bacteria can occur naturally in the soil, especially in fields that have grown nitrogen-fixing crops like soybeans in the past, sometimes nature requires a little help for increased production.
March 3, 2016 – There are some clear advantages to seeding canola early, including high yield and mitigating pest issues. This spring ensure that your planting equipment is ready to go early in the season and get your canola crop off to a quick start. Ideal planting dates in Ontario are typically in late April and early May. Germination can occur at soil temperatures as low as 1 C or 2 C, but emergence will be more rapid at higher temperatures. Data posted by Canola Council of Canada suggests that if temperatures stay at 3 C it may take up to 14 days before full germination is achieved. At 6 C it will take only eight days. However, beginning seeding at 3 C or 4 C soil temperature is a reasonable target if soil conditions are fit for planting and temperatures are expected to rise. Even though soil conditions may be cool, early seeding will typically result in higher yields as long as adequate plant stands are established. Soil conditions are, of course, of primary importance. Good soil moisture in the seed zone and adequate seed-to-soil contact are important for emergence. Residue should be evenly distributed and a firm seed bed will improve seed placement. With late seeding there may not be adequate moisture to seed at the recommended half-inch to one-inch depth, and deeper seeding will reduce emergence rates. Spring frost can be an issue because the growing point is above ground and exposed between the cotyledons (seed leaves). However, a light frost may be tolerated, particularly if canola has reached the three or four leaf stage. If plants have “hardened” over several days of cold weather, they may be more tolerant of frost than rapidly growing plants. On the other hand, seeding late in May can lead to flowering during hot weather in late June and July and this temperature stress can have a huge impact on yield. Good stand establishment and rapid, early growth is ideal for mitigating issues caused by insect pests. Flea beetle emergence from overwintering sites will peak at soil temperatures of 15 C, and it may take up to three weeks for all adults to emerge. Insecticide seed treatments control flea beetle for about three to four weeks, but slow early growth can mean that protection is lost before canola has passed out of the susceptible growth stage. At the three to four leaf stage, canola should be better able to outgrow the feeding damage. Rapid, early growth is also ideal where swede midge is a concern. Swede midge adults emerge from the soil in mid-May to early June and larvae feed on the growing point at the center of the plant. A crop that bolts early may escape significant damage, and risk of damage is not a concern after flowering is initiated on secondary branches. Canola planted in late May or early June in areas with a history of swede midge faces high risk of damage. Consider what the ideal seeding rate is for the given conditions. In an average year somewhere between 40 and 60 per cent of the planted seeds will emerge. The ideal plant population is seven to 13 plants per square foot, or 4.5 to six plants per foot of row on 7.5-inch rows. There are benefits to having a dense stand, including increased light capture, mitigating losses to insect pests, and less branching leading to earlier and more even maturity. Your seeding rate should factor in the seed size, compensate for low emergence rates, and provide a final stand well within the ideal population for the best final yield results. Note that at a seed size of 4.75 g and seeding rate of five pounds per acre, a typical 60 per cent emergence rate will result in around just four plants per foot of row. For very early or very late plantings the seeding rate could be bumped up by five to 10 per cent. A uniform stand will likely yield more than a non-uniform stand, even at the same plant population. In uneven stands the plants will compete for soil and light resources, and will branch more in thin areas causing delayed and uneven maturity. After the crop emerges, determine the plant population and percent emergence, and note the uniformity of the crop. If there is a regular pattern across the field, uniformity may be affected by issues with your planting equipment. Take notes so you can make further improvements next year.
There’s another root rot pathogen in the neighbourhood. It’s called Aphanomyces euteiches. It loves peas, lentils and waterlogged soils. And it’s tough to deal with because its resting spores can survive in the soil for many years. Although Aphanomyces has been present in Manitoba since the late 1970s, researchers only recently identified it in Saskatchewan and Alberta. Now they are at work on some new strategies for managing it. Aphanomyces euteiches is an oomycete, or water mould, which is a fungus-like organism. It produces one generation in a season. “The oospores are the primary inoculum left behind in the soil or decaying host tissue. They are thick-walled, very resistant resting structures. Reports in the literature indicate they can survive in the soil from five to upwards of 20 years, depending on weather conditions,” explains Syama Chatterton, a plant pathologist with Agriculture and Agri-Food Canada (AAFC) in Lethbridge, Alta. “A susceptible host plant releases root exudates and signals into the soil. Oospores respond to those signals and germinate. Through a complicated germination process, they eventually produce zoospores, which are single cells with two flagella that help them swim.” They swim in soil water films to the host root and attach themselves to it. “Then they produce hyphae, the fungal strands that penetrate into the root, and very rapidly begin colonizing it.” They break down the root tissues, feeding on the nutrients. Once they have used up all the nutrients in the root, they form oospores. The whole life cycle can be completed in about three weeks if temperature and moisture conditions are ideal. Infection can occur at any stage of the host’s development, with the timing depending on the environmental conditions. Soggy, warm conditions are ideal for infection. “Aphanomyces often occurs in a complex with other root rot pathogens, like Fusarium, Pythium and Rhizoctonia. They all like moist conditions, but the oomycetes – Pythium and Aphanomyces – do even better with excess moisture,” says Faye Bouchard, provincial plant disease specialist with the Saskatchewan Ministry of Agriculture. On the Prairies, optimal soil temperatures for Aphanomyces infection (22 to 27 C) are typically reached by about July (see Table 1). Chatterton has done Aphanomyces host range work with Sabine Banniza at the University of Saskatchewan. They have found that peas and lentils are both highly susceptible, whereas dry beans, fababeans, chickpeas and soybeans all have pretty good resistance. Alfalfa is somewhat susceptible, but some alfalfa cultivars are resistant. In 2015, Chatterton surveyed alfalfa crops grown on fields that have had peas in the rotation and found that the alfalfa roots were very healthy, suggesting that Aphanomyces is probably not a big concern for alfalfa. Why now?“Aphanomyces has been around in Canada since the 1930s. But we just found it in Saskatchewan in 2012 in peas,” Bouchard notes. “Then we started doing more surveys for it, and Alberta started looking for it [and found it in 2013].” These surveys show the pathogen is fairly widespread in both provinces. So why has Aphanomyces root rot suddenly become an issue? “My hypothesis comes down to three reasons that have all come together in a perfect storm,” Chatterton says. “The first reason is that we’re reaching the point where most places in Alberta and Saskatchewan have had a good 25-year cropping history of either peas or lentils. So, if producers are using good rotational practices with a pea or lentil crop once in every four to five years, then some fields would have had a pea or lentil crop six to seven times, or more often if they have tighter rotations. If a field started with a low inoculum level…the amount of inoculum would gradually build up every time a susceptible host crop was planted because the oospores can survive for a long time. It would take about six to seven cropping cycles to reach a threshold level of inoculum where it is more widespread throughout the field and can cause visible damage,” she explains. “The second reason is that we had several really wet springs in a row, and Aphanomyces is dependent on having saturated soils in order to infect. So you get increased infections because the environmental conditions are right, and the inoculum load in the soil increases quite quickly.” And the third reason is a detection issue. “In previous root rot surveys, they were taking pieces of roots and plating them out on agar to determine the causal agent. But usually Fusarium over-grows Aphanomyces on the culture, so it can be really hard to confirm Aphanomyces. I think it was Sabina Banniza who decided in 2012 to do a PCR test [which uses DNA markers specific to Aphanomyces euteiches]. That was the first time we were able to confirm Aphanomyces in [a Saskatchewan sample]. For our Alberta surveys in 2013 and onwards, we’ve expanded to using that PCR test. It has definitely improved detection of Aphanomyces.” In Chatterton’s root rot surveys for 2013, 2014 and 2015, root rot was found in about 70 per cent of the surveyed fields each year, but disease severity varied greatly from year to year. The highest root rot levels occurred in 2014 because it was a particularly wet year. Chatterton says, “In 2014, we found that root rot was common and widespread throughout Alberta. The results from the PCR tests showed Aphanomyces was present in about 44 per cent of all fields in Alberta and in 60 per cent of fields that had root rot symptoms.” The PCR analysis of the 2015 Alberta samples is not yet complete, but the field surveys showed root rot severity was definitely lower than in 2014, due to the very dry conditions in 2015. The Alberta surveys also show that “Aphanomyces-positive fields are more common in the Black and Gray soil zones that are more typical of central Alberta. I think that is because they have had a pretty long history of pea production there, and those areas tend to be wetter than southern Alberta,” Chatterton notes. “In southern Alberta’s Brown soil zone in 2014, only about 18 per cent of the fields were positive.” Although Saskatchewan didn’t do a formal root rot survey in 2015, the dry conditions in the spring and early summer likely reduced the amount of disease. Bouchard didn’t see as much root rot in the field, she didn’t get as many inquiries about it from growers, and fewer samples were submitted to the ministry’s Crop Protection Lab. Difficult to diagnose in the fieldTrying to figure out which root rot pathogens you have in your field isn’t easy. Aboveground, they share the same symptoms, like poor emergence, wilting, yellowing and stunting. The belowground symptoms are usually a confusing mix caused by a complex of pathogens. In the lab, if you infect plants with only Aphanomyces, the symptoms are distinctive. “The whole root system will have a honey-caramel discoloration. And the classical symptomology is that the epicotyl, which is the portion between the point of seed attachment and the green stem, becomes very tightly constricted and has that same honey-brown colour, which stops abruptly right at the green stem,” Chatterton explains. “Also, because the disease causes decay of the entire root cortex but not the vascular system, oftentimes if you pull up the plant from the soil, only the white vascular bundle is left and the rest of the roots are gone.” In the field, Fusarium species tend to colonize tissue that Aphanomyces has already started to infect, producing mixed symptoms. “The roots will look black and will be pruned away; Fusarium causes pruning of the roots. So you get an ugly mess of a black taproot and brown decaying lateral roots,” Chatterton says. “A good way to check for Fusarium is that it causes red colouring in the vascular system.” When a root rot infection is advanced, it is especially difficult to figure out the original cause. “Not only are the roots rotting and the plant dying, but there could be multiple root rot pathogens as well as saprophytes, which are fungal organisms that live on the decaying and dead plant material,” Bouchard says. She adds, “The other difficulty is that it is hard to separate out the damage that excess moisture causes to the crop, even without any pathogens present. Lentils and especially peas don’t like wet feet, when the plant is sitting in too much water. Those conditions alone will mean that the roots won’t develop as well and probably won’t form nodules as nicely, and the above-ground plant parts will probably be yellowing, stunting and wilting. But those wet conditions stress the plant, so if a pathogen is present, it will probably cause even more damage because of the stress.” The best way to tell which root rot pathogens are present is to send samples to a diagnostic lab, such as Saskatchewan’s Crop Protection Lab, Discovery Seed Labs or BioVision Seed Labs. Seeking more management optionsResearchers in Alberta and Saskatchewan are tackling Aphanomyces from several angles. For example, at the University of Saskatchewan, they are working on developing resistant lines of peas and lentils. To assess various Aphanomyces management practices in field peas, Chatterton initiated a large study in 2015. The study is taking place at Drumheller, Brooks, Taber, Lethbridge, Saskatoon, and two sites in the Red Deer-Lacombe area. Collaborating with Chatterton are Mike Harding and Robyne Bowness at Alberta Agriculture and Forestry, and Bruce Gossen at AAFC in Saskatoon. The Alberta Crop Industry Development Fund, Alberta Pulse Growers and AAFC, through the Growing Forward 2 Pulse Cluster, are funding the study. At each site, the study is evaluating seed treatments, cultivar resistance and soil amendments. All sites are in producers’ fields. Six of the seven sites were selected because the fields had a high risk for Aphanomyces root rot; the Lethbridge site only had Fusarium root rot. The seed treatment trials include different combinations of various products with activity against Fusarium, Pythium, Rhizoctonia and Aphanomyces. The seed treatment for Aphanomyces is ethaboxam (Intego Solo) – a new option that was given emergency use registration on field peas in Alberta, Saskatchewan and Manitoba in 2015. The cultivar trials involve 20 pea cultivars, including some currently popular cultivars as well as some that are just about to be released. The soil amendment trials are comparing three possibilities. “We searched the literature for any instance of something that might have some effect against Aphanomyces,” Chatterton explains. One treatment uses calcium, involving spent lime from the sugar beet industry; calcium has reduced zoospore production in greenhouse tests. Another treatment is Phostrol, a phosphite-based product, which has activity against oomycetes and provided some suppression of Aphanomyces in peas in the Pacific Northwest. The third treatment is the herbicide Edge (ethalfluralin), which showed Aphanomyces suppression in some preliminary work a few decades ago. In the study’s first year, all the cultivars were susceptible to Aphanomyces root rot, as expected from previous greenhouse testing at the University of Saskatchewan. “The seed treatments and soil amendments gave some promising results early in the season. By about five to six weeks, we could see some nice visual differences in root rot severity between some of the treatments,” Chatterton says. “But by the end of the growing season, the root rots were pretty similar across the board. Some treatments definitely yielded better than others, but we didn’t find any statistically significant differences between treatments.” With only one year of data in an unusually dry year, it’s too soon to draw any conclusions. Also, Chatterton points to a key challenge with trying to do these types of field trials. “Because the distribution [of Aphanomyces] can be very patchy in fields, we had to choose sites with very high levels of Aphanomyces root rots. I think the inoculum load at some of these sites is too high, and at that level, disease management strategies often aren’t going to work. We could try to find sites that have a lower level of Aphanomyces, but then we won’t be certain that the inoculum has spread throughout the soil [so some plots might have different levels of inoculum].” The researchers will be repeating the trials in 2016. Then, Chatterton hopes to get continued funding for several more years to determine how low the inoculum levels need to be for the practices to be effective. In a project funded by the Saskatchewan Pulse Growers, Chatterton and Banniza are determining how much Aphanomyces inoculum is needed to cause different levels of the disease. “Right now, you can submit samples to a lab to find out if Aphanomyces is present or absent, but the lab can’t determine if you have a low or high risk of getting Aphanomyces root rot,” Chatterton says. “So we want to determine the amount of inoculum needed in the Brown, Dark Brown and Black soil zones to get low, medium or high disease levels. The idea is that interested testing labs could then offer a DNA quantification service for Aphanomyces and be able to use the DNA levels to determine if a field has a low, moderate or high level of Aphanomyces. That should help inform decisions on the length of time peas or lentils might need to be out of the rotation, or whether the grower could look at seed treatments or maybe a soil amendment treatment.” Advice for growersAt present, the best strategy is to submit plant or soil samples to a diagnostic lab to determine which root rots are causing problems in your fields, and if Aphanomyces is an issue, then use that information in your management decisions. For fields that are highly infested with Aphanomyces, Bouchard and Chatterton advise waiting at least six years before planting peas or lentils again. Bouchard says, “Hopefully growers won’t have to do that on a permanent basis because there should be more options available as more research is done. One seed treatment, called Intego Solo, is available now, and there are potentially other treatment options coming down the pipeline. And hopefully we’ll get some resistant varieties.” In the meantime, Chatterton suggests, “If you want to grow a pulse crop [on a field that is heavily infested with Aphanomyces], then fababeans are a really good option because they are really resistant to Aphanomyces.“ For fields with low to moderate Aphanomyces infestations, Chatterton recommends extending pea or lentil rotations from three or four years to perhaps five or six years. She adds, “Those are good fields for possibly using a seed treatment with activity against all the pathogens in the root rot complex, and that should help to boost your crop and keep it healthier.”
Nov. 24, 2015, Mississauga, Ont. – BASF’s HiStick brand inoculants will change its name to Nodulator. Only the name will change, and growers and retailers will see a transition over the next two years. In 2016, HiStick PRO will transition to Nodulator PRO. In 2017, HiStick N/T liquid and self-adhering peat will transition to Nodulator N/T liquid and self-adhering peat. In addition, Nodulator PRO 225 will launch with seed partners in 2016. For more information about the Nodulator brands visit www.agsolutions.ca.
July 23, 2015 - Reports of aphid infestations have been common during the past couple of weeks with areas affected throughout Saskatchewan. Many of the reports have been from southwest Saskatchewan in lentil crops. Both pea and lentil appear to be the most affected. Timing and necessity of insecticide applications should be treated on a case by case basis. Early application of insecticide likely won't provide a yield response but will affect beneficial predators (e.g. lady beetle larvae and adults) and wasp parasites. Late application would have no beneficial result and will be an unnecessary expense as the aphids cannot damage crops that have completed seed filling. READ MORE.
Thiamethoxam, a broad-spectrum neonicotinoid insecticide contributes to better seedling vigour compared (as compared to no treatment) says Clarence Swanton at the University of Guelph. Do certain seed treatments go beyond protecting young plants from insect pests? That’s an important question, especially if the seed treatment is a neonicotinoid insecticide. Neonics are currently under intense scrutiny by government agencies in many countries and their use is being restricted in some jurisdictions. It’s clear that at least one neonic seed treatment seems to provide more than insect pest protection in corn, but just what protection it provides and how it does so hasn’t been completely clear. “Thiamethoxam is a broad-spectrum neonicotinoid insecticide that, in seed treatment form, contributes to better seedling vigour compared to no treatment,” Clarence Swanton, a professor in the department of plant agriculture at the University of Guelph (U of G), says. Thiamethoxam controls a wide variety of commercially important crop pests, and is used as a foliar spray or soil treatment (Actara), or as a seed treatment (contained within Cruiser). “When thiamethoxam is applied to seed, we see increased germination rates, faster root growth, greater seedling heights and more biomass accumulation, but the physiological mechanisms by which these enhancements occur is not well known,” Swanton explains. “Other researchers have measured the ability of thiamethoxam to do things such as increase the antioxidant capacity of a certain molecule found in corn seedlings, called salicylic acid, which is an antioxidant that plays an important role in the defence against plant pathogens. It is also able to improve plant response to abiotic and biotic stresses, including those caused by the presence of weeds.” However, thiamethoxam seed treatment may be helping seedlings perform better because it reduces the amount of hydrogen peroxide (H202), a free radical that can accumulate in a seedling due to the stress of having weeds nearby. (Free radicals cause damage in plant and animal cells through a process called oxidation.) “Thiamethoxam may be elevating the expression of genes involved in natural scavenging and destroying of H202, in addition to genes involved in other metabolic pathways. This is what we wanted to find out more about,” Swanton says. Swanton and his colleagues have investigated how much better corn seedlings perform with weed pressure, with and without thiamethoxam as a seed treatment. They conducted measurement and analysis at the plant (macro) level, as well as at the molecular level. In addition to Swanton, the team included Maha Afifi, Elizabeth Lee and Lewis Lukens, a research team at the department of plant agriculture at the U of G. In a laboratory environment, thiamethoxam-treated seeds were planted, with some of the resulting seedlings growing up in the presence of neighbouring weeds (a perennial ryegrass). The researchers harvested seedlings at the fourth-leaf-tip stage, washed the roots, and counted and measured crown roots. Shoots and the entire root system were then bagged separately and dried to determine total shoot and root biomass. Other seedlings were harvested for physiological and molecular analysis. “At the macro level, we found the treated corn seedlings showed enhanced root development and seedling vigour, with none of the shade avoidance characteristics that typically develop when there are neighbouring weeds present,” Swanton explains. “We believe this was a result of morphological, physiological and molecular processes. This is the first report to identify the mode of action of thiamethoxam within the physiological mechanisms of early crop and weed competition. “In short, our results suggest thiamethoxam enables corn seedlings to maintain their antioxidant protective system to avoid damage caused by oxidative stress from neighbouring weeds,” Swanton says. Swanton, Afifi, Lee and Lukens found thiamethoxam reduced H202 accumulation, as well as the subsequent damage caused to cells by its accumulation. “It seems to accomplish this through boosting the capacity of genes involved in scavenging this free radical,” Swanton says. “Preventing the accumulation of H202 and enhancing the entire antioxidant system means the plant experiences less cellular damage caused by abiotic and biotic stresses, such as lower light levels caused by neighbouring weeds. The plants from treated seed don’t have to expend as much energy for cellular repair and the energy can therefore be used for growth and maintenance of plant tissues. So, these results suggest plants from thiamethoxam-treated seeds may be better adapted for survival under harsh environmental conditions.” Swanton believes these results have several other implications for the role of seed treatments in agriculture. “Normally, seed treatments are thought of only in terms of insect and disease control, but the results of this study suggest it may be very worthwhile to explore entirely new chemistries and new modes of action in novel seed treatments to enhance free radical scavenging and activate genes involved in the antioxidant defence system,” he says. “It’s clear from our study and the work of other researchers that some seed treatments have this capacity, and that may be critical in the development of crop hybrids and cultivars that are more stress tolerant to weed competition.” The researchers are now investigating whether soybean seedlings grown from thiamethoxam-treated seed will demonstrate the same responses to weed pressure as those of corn seedlings.
Presented by Franck Dayan, professor, department of bioagricultural sciences and pest management, Colorado State University, at the Herbicide Resistance Summit, Saskatoon, Feb 27-28, 2018.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 actionWhen 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. Chart: Use of PPO inhibitors 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. Management strategiesI’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.
Weed resistance to herbicides is not a new issue. Canada has reported resistance issues in weeds to at least six different herbicide groups. As an increasing number of weeds no longer respond to herbicide, it is important to know more about the issue and how to detect it.
The big story in 2017 was that canola surpassed wheat as the number one crop, and the most common rotation in Western Canada is canola-wheat, which certainly has implications for resistance management.
The first resistant population identified in Europe was a pigweed resistant to atrazine in Austria in 1973. Later on through the 1980s and 1990s, many weed species developed resistant to PSII inhibitors (Group 5), mostly to atrazine. More recently, there has been a dramatic increase in resistance to ACCase (Group 1) and ALS (Group 2) inhibitors in grasses since 1990.
Gowan Canada's Edge herbicide has been granted a minor use label extension for industrial hemp.
With the introduction of Monsanto’s glyphosate- and dicamba-resistant soybean into the Canadian market in 2017, producers may be wondering if there is any benefit to tank-mixing the two herbicides for weed control.
The Pest Management Regulatory Agency (PMRA) in Canada has granted approval for the registration of Lumisena fungicide seed treatment.Lumisena, from Corteva (the agriculture division of DowDuPont), provides protection against Phytophthora root rot, the leading soybean disease in North America. Lumisena moves within the plant to protect against multiple stages of the Phytophthora pathogen's life cycle through preventative, curative, eradicative and antisporulant activity. In multiyear, on-farm trials, Lumisena was shown to significantly improve soybean stands and plant health under Phytophthora pressure, according to a press release. Growers can expect Lumisena to be commercially available at 2019 planting timing.
Foliar diseases in barley can be a challenge for growers; increasingly so as the trend to shorter rotations continues. Fungicides are just one of many disease-management tools. Protecting the upper leaves in the barley canopy are important for grain filling and yield, with flag leaf to head emergence in barley as the recommended fungicide application timing.
Is there an interaction between seeding rate of pea and lentil, disease incidence, and fungicide effectiveness? This question was the driving force behind an Agricultural Demonstration of Practices and Technologies (ADOPT) Program project.
Syngenta Canada Inc. has announced the launch of Aprovia Top fungicide, offering Canadian potato growers a new tool for foliar early blight control and brown spot suppression. Early blight, caused by the Alternaria solani fungus, is found in most potato growing regions. Foliar symptoms include small, brown, irregular or circular-shaped lesions that form on the potato plant’s lower leaves later in the season. The disease prefers warm, dry conditions to develop, and can be more severe in plants that are stressed and weakened. Brown spot, caused by the Alternaria alternata fungus, is closely related to early blight and is found wherever potatoes are grown. Unlike early blight, brown spot can occur at any point during the growing season, producing small, dark brown lesions on the leaf surface. Aprovia Top fungicide combines two modes of action with preventative and early curative activity on these two key diseases. Difenoconazole (Group 3) is absorbed rapidly by the leaf and moves from one side of the leaf to the other to protect both surfaces against disease. Solatenol (Group 7 SDHI) binds tightly to the leaf’s waxy layer and is gradually absorbed into the leaf tissue to provide long-lasting, residual protection. Aprovia Top is available now for use in 2017 production. In potatoes, one case will treat up to 40 acres.
Syngenta Canada has announced the new Trivapro fungicide to barley growers across Western Canada, providing broad-spectrum leaf disease control. Trivapro is the first foliar fungicide on the market to combine three powerful active ingredients and three modes-of-action. The product contains propiconazole (Group 3), a curative fungicide that acts on already-present disease to halt further infection, azoxystrobin (Group 11), a preventative fungicide that provides disease protection by moving into new growth, and Solatenol, a powerful Group 7 succinate deyhydrogenase inhibitor (SDHI) fungicide. The unique chemistry in Solatenol allows it to bind to the waxy layer of the entire leaf, where it is absorbed slowly over time to provide long-lasting residual protection. Syngenta research trials show Trivapro to be highly effective on key cereal diseases, including barley scald, tan spot and net and spot blotch, while providing improvement in yield potential. Trivapro also demonstrates superior performance on major rusts, including leaf rust (Puccinia hordei), stem rust (P. graminis) and stripe rust (P. striiformis). The Trivapro co-pack should be applied once at early flag leaf timing. Growers should consult the Trivapro product label for additional information. In addition to being registered on barley, wheat and oats, Trivapro is also registered for use in corn and soybeans to protect against several foliar diseases, including Northern corn leaf blight and grey leaf spot in corn, and Septoria brown spot and frogeye leaf spot in soybeans. Trivapro fungicide will be available in spring 2017 as a 40-acre co-pack or 400-acre bulk co-pack.Visit syngenta.ca to learn more.
Growers in Western Canada now have new options for controlling the most damaging diseases with the registration of Hornet fungicide and label updates for INTEGO Solo seed treatment from Nufarm Agriculture Inc.
Canadian growers may find it challenging to remain globally competitive due to an accelerating reduction in access to pest management tools. Two ongoing issues have reduced the competitiveness of Canadian farmers for decades: The continuing loss of or lack of access to pest management products due to regulatory issues, and regulatory impediments to the registration of new crop protection products.
Corn growers across Ontario and Quebec now have the option of applying Delegate insecticide by air for control of Western bean cutworm (WBC) and European corn borer.
Two of the most commonly used insecticides around the world are imidacloprid (neonicotinoid) and chlorpyrifos (organophosphate). In a new paper, published in the journal Scientific Reports, they have been found to be toxic to seed-eating songbirds, even affecting their migration. University of Saskatchewan biology professor Christy Morrissey stated in a press release, “Studies on the risks of neonicotinoids have often focused on bees that have been experiencing population declines. However, it is not just bees that are being affected by these insecticides.” | READ MORE
A group of international scientists is meeting in the national capital to try to convince parliamentarians there is no longer any doubt that common agricultural pesticides are proving toxic to ordinary honey bees. Jean-Marc Bonmatin of the French National Centre for Scientific Research, represents a task force on pesticides within the International Union for Conservation of Nature, which in 2015 released a comprehensive review of more than 1,100 peer-reviewed research studies on neonicotinoids. READ MORE
Bumblebees are less able to start colonies when exposed to a common neonicotinoid pesticide, according to a new University of Guelph study.
With positive 2016 field results, the Environmental Protection Agency has approved registration for a new product for turf, as well as other possible applications. The abamectin-based nematicide product, code-named “VCP-11” is approved for use on turfgrass including greens, tees and fairways. VCP-11 uses Vive’s proprietary delivery system (Allosperse) to help the nematicide penetrate the thatch and control parasitic nematodes below the soil surface. In field trials conducted in Florida, Louisiana, and Australia, VCP-11 increased turf quality over leading competitors. VCP-11 will be available for turf application this year, and is being tested in crops that are also susceptible to nematodes such as soybeans and potatoes in 2017. Field results The field results from 2016 show Vive’s products are delivering on their promises. “Corn yields in 2015 and 2016 saw an average increase of over six bushels per acre. About 80 percent of the 24 fields in the program had a yield bump with in-furrow AZteroid FC application,” says Darren Anderson, co-founder of Vive Crop Protection. Several growers were also able to skip expensive applications at tassel due to reduced disease pressure and increased plant health. “The Allosperse delivery system in AZteroid FC is the key; it allows the fungicide to be compatible with salty liquid fertilizers. Most in-furrow pesticides are not compatible with starter fertilizers and can separate in the tank or plug the application equipment. Allosperse has solved this problem,” says Anderson. The tank mix has a one-pass application, it survives delays due to weather and doesn’t require special equipment. The first two products developed by Vive using the Allosperse technology are the fungicide AZteroid FC and the insecticide Bifender FC. Both mix uniformly with liquid fertilizers to be applied at planting. Both are approved for key crops in the U.S. Midwest including corn, soybeans and potatoes. AZteroid FC is also approved for use on sugar beet, cotton and peanut crops. “For sugar beets, control of Rhizoctonia is a key issue. The best solution is azoxystrobin in-furrow with a starter fertilizer – which is what we offer with AZteroid FC. In a sugar beet trial conducted at North Dakota State University, when AZteroid FC was applied with starter fertilizer, crops out-yielded fungicide seed treatment by 1.5 tons per acre. AZteroid FC in-furrow, on top of seed treatment with an early-season banded application, out-yielded seed treatment alone by 4.5 tons per acre,” says Anderson. AZteroid FC in seven potato trials saw increases of 24 cwt/acre on average.
In Western Canada, more phosphorus (P) continues to be removed in cropping systems than is being replaced. On average only about 75 per cent of P is being replaced every year, and although the gap is closing, it is probably not quick enough.
The government of Saskatchewan and Fertilizer Canada have signed a three-year extension to their 2016 Memorandum of Cooperation (MOC) in support of 4R Nutrient Stewardship (Right Source @ Right Rate, Right Time, Right Place).
BrettYoung Seeds Limited has launched Recover PO4 phosphate solubilizing inoculant for Canada.
All soils are not equal. Rich loams support the world's most productive agricultural regions, including swaths of the American Midwest. But in some parts of the Midwest, including areas in Missouri and Illinois, claypan soils dominate. And where claypans reign, problems for producers abound. New research from the University of Missouri could help claypan farmers improve yields while saving costs. | READ MORE
There are both environmental and agronomic concerns surrounding the management of livestock manure. The major environmental concerns are: potential risk of nutrient accumulation in soil – particularly nitrogen (N) and phosphorus (P) – and risk of nutrient movement into surface or groundwater. Poor manure management can also cause accumulation of salts in soil, surface water or groundwater and pathogenic micro-organisms in surface water.
Industrial fertilizers help feed billions of people every year, but they remain beyond the reach of many of the world’s poorest farmers. Now, researchers have engineered microbes that, when added to soil, make fertilizer on demand, producing plants that grow 1.5 times larger than crops not exposed to the bugs or other synthetic fertilizers. | READ MORE
A dose of microbes can let plants better withstand drought conditions by growing more leaves and roots and using less water, research shows.
March 31, 2016, Canada – WinField has expanded its Canadian product portfolio with the recent registration of Ascend SL plant growth regulator by the Canadian Food Inspection Agency. Ascend SL is a soluble liquid plant growth regulator that contains a combination of cytokinin, gibberellic acid and indolebutyric acid that can fuel early plant germination and emergence. Research shows that Ascend SL plant growth regulator can increase yield potential when applied in-furrow for corn at planting, according to a company press release. Three years of field trial data from almost 200 locations showed that when combined with zinc 10% and a starter fertilizer (10-34-0), Ascend SL generated an average corn yield response of 4.8 bushels per acre more than in starter fertilizer applications without Ascend SL in trials across the United States. In addition, Ascend SL plant growth regulator can be applied in combination with other seed treatments to help wheat crops with early season vigor, so they can withstand yield-limiting stresses throughout the growing season.
Crops require a number of nutrients in very small amounts called micronutrients. The most common micronutrients include boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn). There are at least five other elements that are needed by specific crops (that we won’t discuss in this article). The term micronutrient refers to the relatively small quantity of a nutrient that is required for plant growth. It does not mean that these nutrients are less important to plants than other nutrients. Table 1 below shows the total amounts of micronutrients taken up from the soil by high yielding wheat, barley and canola. Plant growth and development may be retarded if any one of these elements is lacking in the soil. Fortunately, we do not have widespread micronutrient deficiencies in Western Canada. Sources of micronutrients in soilsInorganic forms of micronutrients occur naturally in soil minerals. As minerals break down over time, micronutrients are gradually released in forms available to plants. Two sources of readily available micronutrients are nutrients that are adsorbed onto soil colloids (very small soil particles) and nutrients that are in the form of salts dissolved in the soil solution. Organic matter is often an important source of most of the micronutrients. As soil organic matter decomposes, plant available micronutrients are slowly released into soil. Soil sampling and testingSoil testing can be helpful as an initial screening to determine if any of your fields are potentially low or marginal in a micronutrient. Have representative 0 to 6 and 6 to 12 inch depth soil samples analyzed for micronutrients. Most soil testing labs in Western Canada determine metal micronutrients Cu, Fe, Mn and Zn, using the diethylene triamine pentaacetic acid (DTPA) method. Boron is extracted using hot water and chloride is determined using water. The general range levels used for determining when to add micronutrients to improve crop production are shown in Table 2, below. When a soil sample tests low in a micronutrient, a potential micronutrient deficiency may occur. A crop grown in field with a low micronutrient level in the 0 to 6 inch depth may not respond to a micronutrient fertilizer if adequate levels of the micronutrient occur in the 6 to 12 inch depth. It is important for farmers and agronomists to recognize soil testing for micronutrients is not an exact science. The DTPA method for determining metal micronutrients works reasonably well for copper and zinc. The challenge is having reliable field research to determine the critical levels at which crops will economically respond to micronutrient fertilizers in the various soil and agro-ecological regions of Western Canada. Good research information is available for copper, limited information for zinc and very limited information is available for iron and manganese. Up to now, crop response to micronutrients across the Prairies has been minimal, making it difficult to accurately determine the critical soil test levels at which micronutrient responses may occur. There isn’t a suitable soil test for molybdenum. The present soil tests used for boron and chloride are not very effective to predict crop response to these nutrients. For example, in a study in southern Alberta, about one-third of soils tested < 0.5 ppm for boron, which is often considered deficient. However, research trials conducted with winter wheat, spring wheat, barley, canola, pea, bean and corn at a number of sites over four years showed no positive responses to boron. From this and other work it is very clear the boron test and the critical levels used to recommend boron are not very reliable. Soil factors affect micronutrient availabilityPhysical and chemical characteristics of soil can influence the availability and uptake of micronutrients: Soils with < 2 per cent organic matter may have lower micronutrient availability; for example Gray soils. Medium and fine textured loam, clay loam and clay soils are less likely to be low in plant available micronutrients. Coarse textured sandy soils are more likely to be low in micronutrients. Soils that have very high levels of organic matter > 30 per cent to a depth of 30 cm often have low micronutrient availability, particularly copper. Soil temperature and moisture affect micronutrient availability. Cool, wet soils reduce the availability, rate and amount of micronutrients that may be taken up by crops. Cool soil temperatures can induce micronutrient deficiencies. As soil pH increases up to 8.0 or higher, the availability of metal micronutrients may decrease. BoronBoron deficiencies have been suspected in canola and alfalfa grown on sandy-textured Gray soils. Research to specifically document crop response to added boron is limited. Normally, I would not recommend boron on an entire field based only on a low B soil test, due to the limitations of the test. If soil test B is < 0.5 ppm, I would suggest trying carefully laid out field scale test strips with sensitive crops like canola or alfalfa to determine if a soil B deficiency actually exists. Application of borate or borax fertilizers can be broadcast for alfalfa, and either broadcast and incorporated or banded for canola. Boron containing fertilizers should not come into contact with the seed at planting. Soil application rates should not exceed 1.5 lb/ac on soils with a pH less than 6.5 to avoid boron toxicity problems. Foliar applications should not exceed 0.3 lb/ac to avoid toxicity problems. For all types of applications, extreme care must be taken to avoid toxicity problems. ChlorineThe soil test for chlorine is very unreliable. Therefore, I normally would not recommend chloride on an entire field based only on a low Cl soil test. Generally, crop requirements for chlorine are satisfied by the chlorine in the soil and received in rainfall. Rainwater on the Prairies typically contains 0.5 to 1 mg/l of Cl, which is more than sufficient to meet crop requirements. Chloride is also added to soil in potash fertilizer (KCl). North Dakota research has shown that chloride added at rates higher than required to meet nutritional needs is associated with suppression of root and leaf diseases in some cereal crops. However, western Canadian research is very limited to demonstrate this benefit in Western Canada. CopperResearch has clearly shown cereal crops will respond to added copper when soils tests are low. Wheat and barley grown on Black or Gray soils may benefit with copper application when the soil test for Cu is < 0.5 ppm. Wheat and barley response to copper on Brown and Dark Brown soils is uncommon and copper should only be applied to these soils when soil test Cu is < 0.3 ppm. Cereal crops grown on soils with greater than 30 per cent organic matter to a depth of 30 cm often respond to copper fertilization, when soil test levels are < 2.5 ppm. Generally, copper deficient mineral soils tend to be either sandy or light loam soils with levels of organic matter in the range of six to 10 per cent. Copper deficient soils are sometimes associated with soils with high levels of soil phosphorus or which have received heavy applications of manure. Broadcast and incorporated rates of 3 to 8 lb/ac of copper in the form of copper sulphate or copper oxide are recommended for deficient mineral soils. On organic soils, broadcast and incorporated rates of 10 to 15 lb/ac are necessary. Soil application rates should be effective for five to 10 years. Chelated forms of copper are also effective in the year of application but the residual effects in Prairie soils is not well known. The benefit of copper foliar application to cereal crops grown on mineral or organic soils is not as consistent but can be used when deficiency symptoms appear. Foliar applications are required annually and are most effective at the late tillering stage. If the deficiency is severe, two applications at mid-tillering and boot stage may be necessary. Foliar application rates of between 0.2 to 0.3 lb/ac are recommended. IronIron deficiencies have rarely been observed in field crops in Western Canada. Soybean is a relatively new crop to the Prairies and is particularly sensitive to low soil iron levels. An iron soil test below 3.0 ppm is considered very low and at 3.0 to 5.0 ppm is considered low. These critical levels need western Canadian field research to be verified. Deficiency symptoms with soybean most commonly occur in cool, wet spring conditions. However, research in the U.S. has found the DTPA test is not well correlated to iron fertilizer response. U.S. research generally has found a foliar application of 0.15 lb/ac is recommended versus a soil application for soybean. Note that in the spring as the season warms up, soil iron tends to become more available to the crop and may grow out of the deficiency. ManganeseManganese deficiencies may occur on organic soils and high pH mineral soils. Deficiencies are rare but can potentially occur during cool, wet conditions in spring. Oats are more susceptible to a manganese deficiency than other cereal crops. Organic soils with a high pH are more likely to respond to manganese fertilizer. Only limited information is available on manganese fertilization. As a rule, broadcast applications are less effective. For cereals, a seed placed treatment of manganese sulphate may be more effective. Foliar application can also be used if deficiency symptoms develop during the growing season. ZincZinc deficiencies tend to occur on soils that are calcareous, have a high pH, are sandy in texture and/or have relatively high soil phosphorus levels. Deficiencies tend to occur in spring when conditions are cool and wet. In southern Alberta, irrigated field beans have responded to applications of zinc particularly on sandy soils. Zinc deficiencies have been suspected in some irrigated cornfields in southern Alberta, but research trials have not confirmed this. Response to added zinc may occur on eroded or machine leveled soils or soils that have had large amounts of added phosphate fertilizer. For soils that test low in zinc where a sensitive crop such as beans, corn or wheat is grown, a band application of 2 to 5 lb/ac of zinc sulphate or 0.5 to 1.0 lb/ac of a chelated zinc is suggested. When zinc deficiencies are suspected early in the growing season, a foliar application of 0.5 lb/ac of zinc sulphate can be used. On eroded soils, a 5 lb/ac broadcast incorporated application of zinc sulphate can be tried. It is important to keep the need for micronutrient fertilizers in perspective. Many farmers have applied micronutrients in the hope of increasing crop yields even though there is little evidence to suggest a deficiency exists. Farmers with fields testing very low or low in a micronutrient are encouraged to apply the nutrients in carefully laid out, replicated test strips. These strip treatments must be carefully marked out for comparison to adjacent control strips. Visual comparisons and yield measurements should be made to confirm if a yield benefit actually occurred. There is no doubt soil micronutrient levels will gradually decline as cropping continues. As soils continue to be cropped, micronutrient deficiencies may become more common as available levels of some elements are depleted. Fortunately, most Prairie soils are currently well supplied with micronutrients. Soils and crops in Western Canada that require micronutrient fertilizers are the exception, not the rule. Care must be taken to keep the need for micronutrient fertilizers in perspective and not to promote them beyond their true significance.
With a wide variety of products for crop nutrition, seed and protection, farmers have more supplement and micronutrient choices than ever. Photo by John Dietz. Cautious optimism is likely a good way to approach the new products section for any local ag retail outlet, according to veteran agronomist Norm Flore. Flore has been involved with agriculture, fertilizers and research in Western Canada for 35 years. Currently, he provides agronomic services in retail outlets for Crop Production Services (CPS) in southern Alberta. CPS has a wide range of products for crop nutrition, seed and protection. The shelves are more packed than ever. “There is a barrage of products that farmers are faced with right now, and they have a wide range of claims associated with them,” Flore says. “Our customers, often in conjunction with an agronomic advisor, have to sort through that, especially new products. There’s always been a lot of products out there, but the rate for new introductions seems to be increasing or spiking.” He’s right. Before April 26, 2013, the federal Fertilizers Act Regulations contained quality and efficacy requirements for fertilizer and supplement products. The Canadian Food Inspection Agency (CFIA) enforced these regulations by conducting pre-market efficacy assessments, verification of performance or benefit claims and monitored for product quality in the market. It also required regionally based efficacy data. It reviewed all labels being planned – and took up to three years doing it – to protect customers. If a label claimed a product could improve yield, the agronomist and all customers knew the label claim had hard scientific data. Those CFIA practices were discontinued as of April 26, 2013. The CFIA process for registration takes the same amount of time today, but the scope is narrower. In principle, according to the CFIA, this new flexibility supports innovation, reduces burden and expedites delivery to market for safe fertilizers and supplements. Theresa White, a Monsanto Canada regulatory officer in Ottawa, offers this insight: “The registration-approved stamp means that the product has been assessed by CFIA for safety for human health and the environment and is safe when used according to the approved label information. “The CFIA also reviews product labels to verify that requisite information, such as guaranteed analysis, directions for use, company/manufacturer contact information, appropriate units of measurement, and mandatory cautionary statements, correctly appear and are clearly legible on the label.” Each product registration is valid for three years, after which is must be re-registered. The categories and registration numbers on the CFIA website (www.inspection.gc.ca) can be summarized into four categories: farm fertilizer (50), fertilizer-pesticide (30), micronutrient (335) or supplement (392). Recently, the number of registered supplements has been increasing: in April 2013 the number sat at 291; in September 2015 it increased to 366 with another jump to 392 in October 2015. Registered micronutrients change, too. Twelve micronutrient registrations were issued in the first 10 months of 2015. The companies with most total registrations, as of October 2015, included: Nutri Ag Ltd. (31), Terralink Horticulture (31), Cameron Chemicals (21) and Winfield Solutions (19). The big registration activity recently has been on the other side – registrations for supplements, that is. As of October 2015, the posted list shows 216 active supplement registrations predating 2014 and going back many years. However, 53 new registrations were issued in 2014. Another 74 were issued in the first 10 months of this year. Buyer bewareFor Flore, the issue comes down to data. If a new product has lots of local data, he probably will try it and encourage customers to try it. If it doesn’t have that, it’s time to be cautious. “To go through the registration process now, you don’t have to show product efficacy at all. In a lot of cases, it’s simply claims being made for a product. There’s a lack of good hard scientific research to demonstrate the effectiveness of some products,” the senior agronomist says. For new products, he tries to keep an open mind. He looks for the science behind the label claim, but allows for customer influence. If a grower is interested in something new, Flore eagerly coaches the grower to test the product in the local environment. He believes newcomers to the market should have a fair trial. “Yes, I tend to be skeptical on many of the products that are introduced especially if there are no claims on the label or a lack of performance results in the local area,” he says. “Still, I encourage customers to give it a try. I like being in the field with growers. I say, let’s try it in this environment where it has the best chance of working. I’ll monitor it. I’ll even do some crop yield and quality assessments to get a handle on whether a product is working.” Product introduction time is a good time to ask if some product is available at no cost – select suppliers offer some product at no cost in exchange for some data on its performance. A fair trial, Flore suggests, can be in proportion to a farmer’s confidence in the likely benefit from a new product. For example, he suggests, if there’s a 20 per cent chance of a benefit, try it on up to 20 per cent of a field or a crop. “Talk to the reputable local agronomist and the input supplier to learn what they’ve seen and what they’ve heard, in the area, about the product or the type of product. We don’t have all the answers, so I encourage quality on-farm testing,” he says. Or, after consulting a bit, perhaps buy the smallest jug or package available. In most cases, one container is enough to get a feel for the product performance. “Work with an agronomist to help you select the right product, right field, the right crop, the right timing, the right application method to do things as well as possible. Then, use GPS technology and do 20 or 40 acres. You know exactly where it’s at and you can assess the yield,” he says. “We can’t wait now for third-party research to cover off all these different products, it’s just not happening. There’s very little independent third-party research left out there, so it goes back to growers to do their own testing.” BioAg Alliance activity growingNovozymes and Monsanto lead the registrant activity for micronutrients and inoculants. They account for 108 of the nearly 400 registered products in the CFIA list of supplements as of October 2015. The two companies formed BioAg Alliance in February 2014 with a mandate to provide sustainable bioagricultural solutions. Many of the “me-too” new registrations for Monsanto reflect its new access to Novozymes technology. The companies say the BioAg Alliance is meant to bring the capabilities of Novozymes in microbial discovery, development and production together with Monsanto capabilities in microbial discovery, advanced biology, field-testing and commercialization. The stated goal of the alliance is to help farmers meet the challenge of producing more with less in a sustainable way. Monsanto BioAg is the commercial division of the BioAg Alliance. This year, Novozymes BioAg gained 13 registrations for QuickRoots in either wettable powder or a dry formulation, for soybeans, small grains, corn, canola, alfalfa or pulse crops. Meanwhile, Monsanto BioAg broadened its product portfolio by registering 11 of the 13 QuickRoots products with Monsanto labels. “To fully understand what this means, they are primarily Monsanto asking for the registration based on existing Novozymes BioAg product registration,” says Jon Treloar, a technical agronomist with Monsanto BioAg. Treloar says the BioAg alliance is data-driven. Monsanto BioAg is responsible for field-testing in Canada. It proves the efficacy of each claim by doing costly, time-consuming testing. “This year, we had 150 small plot trials at 150 locations across Canada, and we had close to 200 field scale trials through the BioAdvantage Trials program.” However, he adds, supplying the data to prove a label claim is voluntary. The CFIA efficacy requirement has been removed for nearly three years.
When we think of applying fertilizer, the nutrients that come to mind initially are the major nutrients nitrogen (N), phosphorus (P), potassium (K) and sulphur (S). However, there are 10 other mineral elements or nutrients needed by plants – most are micronutrients. In most agricultural soils, widespread shortages of micronutrients are uncommon, but when one or two of them are in short supply, crop growth can be severely restricted and crop yields depressed. In the Northern Great Plains (NGP), it was only a couple of decades ago that micronutrient deficiency began to be considered a significant occurrence. Now, most areas readily accept that micronutrient deficiencies can occur. There are a number of reasons why this has happened. First, farm soils have been cropped longer, with most fields having a crop production history of over 100 years. Secondly, as higher yielding varieties and hybrids have been developed, crop yields and nutrient removal through harvest have continued to increase. Third, agronomic science has continued to improve soil and plant analysis techniques to better detect low availability of micronutrients. Lastly, education of field agronomists and crop advisers has increased the awareness and ability to look for, and diagnose, possible micronutrient deficiencies. A micronutrient deficiency will not occur over a whole field, but will be present in irregularly shaped areas within a field. Patches are often severely affected, and these graduate into moderately affected areas, and finally transition into areas that do not exhibit or have any micronutrient deficiency. This is the result of natural spatial variability in soil characteristics that affect micronutrient availability. These characteristics include soil pH, texture, organic matter, cation exchange capacity, electrical conductivity and soil drainage. Just because there are some areas of micronutrient deficiency doesn’t necessarily mean a whole field should receive a micronutrient application. For example, while field scouting with a farmer for the presence and severity of an insect pest so he could make a decision whether to apply an insecticide or not, he asked me to look at an area of canola that had poor growth. I was able to recognize boron (B) deficiency symptoms and took both soil and plant samples from the poor growth area, as well as from an adjacent area with better crop growth. The analyses confirmed my visual diagnosis of B deficiency, but I’ll admit his response at first was a bit disappointing. He said “I realize you did a great job, but it’s only five acres and there is no sense getting too excited for such a small portion of the field.” His response made sense after some thought, as the benefit of correcting the deficiency on such a small area didn’t justify the time and cost. The patchiness of micronutrient deficient areas in a field and the difficulty of assessing the true extent of a micronutrient deficiency are challenging. I suggest we approach the challenge in much the same way crop advisers approach pest infestation assessments. First, confirm the suspected problem and assess the extent of the field that is affected. Next, make an estimate of what the economic cost will be if nothing is done to correct the problem. Lastly, compare the cost of treating the problem with the value of the expected yield increase if treated with an in-crop foliar micronutrient. If there is sufficient net return from applying a micronutrient to the crop, go ahead with the application. One last word of advice: even if an in-crop micronutrient application isn’t justified using this assessment procedure, it is useful to conduct further soil sampling on the field after harvest to more accurately assess the extent of a micronutrient deficiency. Further investigation may show more of the field may be moderately deficient, and a blanket application of a soil-applied micronutrient containing fertilizer may be a useful decision for longer-term crop production on the field. Dr. Thomas L. Jensen is Director, Northern Great Plains International Plant Nutrition Institute (IPNI). Reprinted with permission from IPNI Plant Nutrition Today, Fall 2014, No. 2.
A response to applied zinc rarely happens on Prairie soils. Zinc (Zn) deficiencies tend to occur on calcareous, high pH soils that have been machine leveled, are sandy in texture or have relatively high soil phosphorus (P) levels. In Saskatchewan and Alberta, some of the earliest fields developed for irrigation were land levelled for flood irrigation, creating the potential for Zn deficiencies. While rare, Zn deficiency has been observed in irrigated alfalfa fields during stand establishment near Outlook, Sask. “I thought Zn response would be a piece of cake on those land-levelled fields but I haven’t been able to prove that you can get a Zn response on those fields, except for a couple cases on newly established alfalfa stands,” says Gary Kruger, provincial irrigation agrologist with Saskatchewan Agriculture at Outlook, Sask. Fields that were land levelled redistributed topsoil so that water could uniformly flow over the field. Kruger says this alteration could result in the soil being unable to supply sufficient zinc for crop growth. Crops such as beans, corn, flax, soybeans, alfalfa, barley, potatoes and wheat are more sensitive to a low supply of zinc from the soil and, as such, may benefit from zinc application. Deficiency symptoms usually show up first in dry bean and lentil, and these crops may be responsive to added Zn. Very high rates of P may also induce Zn deficiency in flax. Kruger first noticed a zinc response at a Miry Creek Irrigation District demonstration site at Cabri, Sask. in 2011, which was established to evaluate the nutrient requirements of a new alfalfa field to provide improved yield, stand longevity and competition with weeds (dandelion). The field had a poor history of production since it was developed in the 1970s. The clay soil had been in annual cereals for several years, and the field was divided into six strips testing the following fertilizer treatments: P alone, potassium (K) alone, P-K-Zn together, P-K together and control treatments. The project was sponsored by the Irrigation Crop Diversification Corporation (ICDC). The field was seeded to Stealth alfalfa on June 12, 2011, with a cover crop of Morgan oats sown at 35 lb/ac. The Stealth alfalfa was sown by splitting the seed in half and double seeding the field at 45 degrees to the direction the cover crop was sown. The alfalfa had excellent emergence and establishment in 2011. A 0- to 6-inch soil sample was analyzed prior to fall fertilization 2010. A critical level of 3.0 ppm in coarse soils and 1.5 ppm in medium to fine soils has been established for dry bean production under irrigation in southern Alberta. This field tested at 1 ppm, rated as low by Midwest Laboratories. Fertilizer recommendations based on a target yield of 3 ton alfalfa/ac from this analysis was 40 lb P205, 9 lb sulphur (S), 1.8 lb Zn, 2.3 lb manganese (Mn) and 20 lb elemental S/ac. Phosphorus was applied to the field at about double the recommended rate suggested by the November 2010 soil analysis. (See Table 1.) Kruger notes that phosphorus fertilization reduces Zn uptake in the alfalfa. Tissue testing at the early bud stage during the year of establishment showed that the Zn levels in the P alone and P-K treatments were lowered to marginal levels in the alfalfa tissue. He observed that during the year of establishment, the alfalfa treatment that had the P-K-Zn fertilizer had a darker green colour. In addition, this treatment had a higher yield in the first cut compared to the other treatments, but that advantage disappeared in the second cut and the second year of harvests. “The difference at the first cut may have been that the alfalfa roots weren’t exploring enough of the soil to obtain enough zinc for growth, but after it grew more later in the year and in the next year, the larger root system increased the plants’ ability to find zinc in the soil, so we didn’t see an advantage after the first cut,” says Kruger. (See Table 2.) Kruger also observed a Zn deficiency in a research project initiated in 2013 and led by Sarah Sommerfeld, regional forage specialist with Saskatchewan Agriculture at Outlook. The project was set up to look at P, K and S fertilizer needs of a new alfalfa stand. During the year of establishment in 2013, a Zn deficiency was noticed. “When they went to put down the fertilizer treatments in October 2013, they found symptoms consistent with Zn deficiencies, and a plant tissue analysis confirmed the deficiency,” says Kruger. With the detection of the deficiency, a Zn treatment was added to the study. This project will carry on in 2014 with yield and forage quality analysis. While these two examples provide an indication of the potential for Zn deficiencies, Kruger cautions that more research is needed to confirm if Zn deficiencies are more widespread than thought. “One of the issues I see with southwest irrigation projects is the longevity and productivity of the alfalfa stands. My gut feeling is zinc may help alfalfa stands remain productive longer. I have also seen that protein content in alfalfa isn’t always up to snuff, and maybe zinc could help deal with that as well,” says Kruger. Another factor that may be at play is that the land-levelled fields can have K deficiencies. Kruger says he has seen very good responses to K fertilizer on alfalfa. Because K stimulates root growth and root exploration of the soil, K fertilizer can help a plant overcome other nutrient deficiencies in fields with irregular fertility due to land leveling. Until more is known about fertilizing alfalfa, Kruger recommends farmers balance their fertility program based on soil test recommendations. He says that if a field was land levelled, a Zn deficiency is likely for sensitive crops and may benefit from a Zn fertilizer application. Zn is easily blended or impregnated on fertilizer, which can be broadcast or banded. “Zinc applied to soils attaches to soil particles and is agronomically effective for many years. I speculate that a three lb/ac application is enough to correct the problem perhaps for a farming career,” says Kruger.
Most lentil producers in Western Canada use pre-harvest desiccants in lentil for two reasons: to speed up crop dry down, which helps with ease and efficiency of harvest, and to achieve perennial weed control going into the next growing season.
May 27, 2016, Ontario – Corn planting is nearly complete in Ontario, and soybean planting isn't far behind, according to the latest field crop report from OMAFRA. CornPlanted acreage across the province is at about 90 per cent complete, with exception of some of the heavier soils in Essex and Lambton counties yet to be planted. Most of the corn acreage has emerged and is at the spike to first-leaf over stage with the most advanced corn at the two-leaf over stage. Corn has recovered from the frost injury of 10 days ago. Some pre-side-dress nitrogen testing (PSNT) will begin next week (see Table 1, Nitrogen Recommendations Based on Nitrate-Nitrogen on http://fieldcropnews.com). Early soil nitrate testing has shown higher than expected soil nitrate levels considering the cool, dry weather thus far this spring. CerealsWinter wheat is at the Zadok 37 to 55 (flag-leaf half emerged to head half emerged) stage, looking good in most areas of the province. Stripe rust infection spread last week from the southwest (Windsor to London) to Huron (Exeter) and Bruce County (Walkerton). Fields with strip rust tolerant varieties or were sprayed early at the T1 stage, have less pressure. Higher nighttime temperatures should slow the development and spread of strip rust (optimum 10 C to 20 C). Growers should continue to scout their fields and if stripe rust is a problem, growers should spray immediately but be aware of wheat stage. Once the wheat reaches boot stage (Zadoks 45), the application of products containing a strobilurin fungicide may increase the amount of mycotoxins in the grain. As we approach the flowering stage (Zadok’s 59), the use of a T3 fungicide to control Fusarium head blight will also control many leaf diseases, such as stripe rust. Weather forecast and DONcast may assist to best co-ordinate need for FHB fungicide application at flowering.Spring Cereals are now in the tillering stage (Zadok 26 to 30). Many annual weeds have emerged and growers should consider spraying.SoybeansSoybean planting about 80 per cent complete across the province, with the exception of only about 50 per cent planted in Essex and Lambton counties. Some emergence concerns in the drier areas on the lighter soils, particularly east of the 400 where soybeans were planted into dry soil.ForagesWinter cereal rye is head half emerged stage. Forage quality drops rapidly as the crop matures past this stage. Orchard grass is headed now and alfalfa is at the early bud stage. A few growers have begun harvest planning to take four cuts this season. Stands with a higher percentage of orchardgrass in the forage mix should be cut soon as quality drops rapidly as the orchardgrass matures. CanolaMost of the planting is now complete. Conditions for emergence have been good. Flea beetle damage has been reported. Fields should be scouted now. This is also the time to set up monitoring traps for swede midge. The adult emergence peak is end of May to mid June. See infosheet for more information. Edible beansThe planting of Azuki Beans started this past weekend. Edible bean growers will be planting this week. Remember to plant to moisture under the dry soil conditions.Weed controlManagement of weeds will become the next priority in corn and soybeans if no pre-emergence herbicides have been applied. In soybeans, scout for weeds at around 10-14 days after planting because many annual weeds will be starting to emerge. Be mindful of environmental conditions at the time of applying post emergent herbicides that would increase the risk of off-target spray drift. In general off-target drift can be reduced when an applicator: • sprays when wind speeds are light to moderate and moving away from the any nearby sensitive crop • uses nozzles having the coarsest effective droplet size that will still achieve effective pest control • reduces the distance between nozzle and target Go to www.sprayers101.com/spray-drift for more specific details about sprayer modification to reduce the risk of off-target drift to sensitive high value crops.
Field surveys across Western Canada are showing an increase in the presence of cleavers. Generally, the vast majority of populations have been identified in Saskatchewan; however in the 2010 weed survey in Alberta, cleavers ranked as the number three weed in canola and number one weed in pulses. Cleavers are difficult to control in many crops and can cause downgrading and reduced crop quality. With funding from the Saskatchewan Canola Development Commission, Western Grains Research Foundation, Government of Saskatchewan Ag Development Fund, and multiple industry partners, researchers at the University of Saskatchewan (U of S) have just concluded a two-year study to help growers in managing cleavers in canola. They characterized the emergence and genetic characteristics of cleavers populations in Western Canada, which were believed to be two species: Galium aparine and G. spurium. Researchers also assessed the response of cleavers to potential new herbicides (in canola) such as quinclorac and clomazone, as well as their response to common canola herbicides such as glufosinate-ammonium and glyphosate to determine whether differences among populations existed. In 2012 and 2013, field experiments were conducted at different locations in Saskatchewan, including Scott, Saskatoon and Rosthern (2014 only). Eight herbicide treatments were used in this experiment, including the herbicide standard for each canola system used alone and with the addition of quinclorac (tank-mix) and/or clomazone (preseed). At all sites, canola varieties (L130, 73-75 and 45H73), resistant to their respective herbicide system, were seeded into cereal stubble. Greenhouse dose-response experiments were also conducted to assess whether variability existed between populations in their response to herbicides. “One of the most important findings from our research for management of cleavers in canola is that a portion of cleavers are emerging in both spring and fall, and that emergence timing of each of these fall and spring cohorts varied between years,” explains Christian Willenborg, assistant professor, department of plant sciences at the University of Saskatchewan. “Historically, cleavers were considered an obligate winter annual and generally emerged in the fall. However, our research confirms what growers and agronomists have been seeing: cleavers have largely responded to our cropping systems and, along with a shifting climate, are now emerging in both fall and spring. These differences suggest growers will need to pay close attention to emergence timing of this weed to ensure the small window for control is not missed.” Another important outcome was that researchers successfully developed a molecular marker that could differentiate and characterize the cleavers species in the field. It has long been believed cleavers populations in fields across Western Canada are a mixture of both species. However, molecular analyses showed all sampled populations were in fact identified as G. spurium, or false cleavers. Although no G. aparine was found in the collected samples, it does not mean there is none present in fields across the Prairies. Willenborg adds that for growers, knowing populations are primarily one species, G. spurium, which is also the species that possesses resistance to Group 2 herbicides, is important because resistance will spread more quickly if all plants within the population are the same species. One of the key recommendations resulting from the study is that growers will have to have a well-planned strategy for managing cleavers at different times in the rotation. “We found that in canola, spring emerging cleavers seem to emerge right after the crop is planted, and are often too large for some in-crop herbicide products, particularly those with a narrower application window such as the two-whorl or two- to four-whorl stage,” Willenborg says. “In some cases, such as the last couple of years, growers were unable to make a fall application because of either inclement weather or the timing of harvest. This can cause problems the following spring, as cleavers plants may be very large at this point and therefore difficult to control with pre-emergence herbicide applications. As well, some in-crop application timings have not been ideal because of the higher than usual moisture conditions.” On the positive side, the results of the field study conducted over two years and at three sites showed that clomazone and quinclorac significantly reduced cleavers biomass and seed contamination and improved cleavers control in canola crops. The results consistently showed that applying clomazone prior to seeding (pre-plant) canola followed by an in-crop application of a herbicide standard provided acceptable control, usually greater than 85 to 90 per cent. The results also showed the tankmix of quinclorac with a herbicide standard applied in-crop brought control to at least 85 or 90 per cent, without a preseed clomozone application. In fields where cleavers populations are a big problem, all three products could be used: preseed clomozone, and the in-crop tankmix of quinclorac and herbicide standard. “In the study, using all three products provided the best results, often with an additional five per cent increase over the other combinations,” Willenborg explains. “However, growers have to assess whether or not the use of all three herbicides will pay for itself.” The results of the greenhouse dose-response experiments appeared to suggest cleavers populations responded similarly to glufosinate-ammonium, imazapyr+imazamox, and quinclorac, despite being from different locations in Western Canada. However, further testing and statistical analysis is needed to confirm this. Both herbicides, although new to Western Canada for cleavers control, are older technologies. Clomozone, which is not yet registered in Western Canada as of December 2015, is a Group 13 product that has been registered in Eastern Canada under the product name Command for several years. Quinclorac, a Group 4 product, is now registered, but growers are cautioned they cannot use quinclorac in canola until the industry addresses MRL (maximum residue limits) considerations in some markets. Registration and acceptance of these herbicides will significantly improve cleavers control in Western Canada. To manage cleavers in canola, growers should start controlling cleavers in the year before growing canola in rotation, such as in cereals where good control options are available. There are some existing Group 4 products, along with two new products registered in 2015, Pixxaro and Paradigm. The active ingredient in these products, halauxifen-methyl branded as Arylex, also has activity on kochia and can be tank-mixed with a range of other products for control of broadleaf and grassy weeds. “The most important recommendation is in addition to in-crop herbicide control strategies, the addition of a fall application is key to managing cleavers over the long-term,” Willenborg says. “Growers need to plan to control cleavers that emerge in the fall prior to growing canola. Glyphosate can be used for control, but growers need to recognize the higher risk of developing herbicide resistance in cleavers, and therefore tank-mixes and well-planned herbicide rotations are key. Avoiding tillage is also recommended as tillage can create situations that encourage germination and recruitment of cleavers seedlings.” Although the addition of these new herbicide options will provide good options for canola growers when available, over the long term they are not a silver bullet. These herbicides, like all herbicide tools, will need to be carefully managed to reduce the risk of herbicide resistance. Cleavers resistance to Group 2 herbicides has already developed across Alberta and Saskatchewan, and cleavers rank second among weeds likely to develop glyphosate resistance in the Black soil zone. “Our study showed that spring applied clomazone reduced the size and stage of cleavers found in-crop, and it is known that lower population numbers reduce the risk of developing herbicide resistance,” Willenborg adds. “Both clomazone and quinclorac, which can be tank-mixed with any of the in-crop herbicides, also provide alternative modes of action for control and by tank-mixing with herbicide standards, should delay the evolution of resistance to glyphosate and glufosinate. “However, in the mid 1990s, some cleavers populations in Alberta were identified as resistant to quinclorac, which is Group 4, as well as some Group 2 products, so there are some multiple resistant populations that already exist in Western Canada. Although these resistant populations haven’t spread very much, the scale that quinclorac could be used in canola in the future could mean an increased selection pressure for this herbicide and this could result in the spread of these populations.” Willenborg is building on this work with some new projects to address some other questions that impact management related to emergence timing and base temperatures. “A better understanding of both emergence timing of spring and fall cleavers, along with corresponding base temperatures, will help us to develop better models to more accurately predict emergence timing for growers,” he says. “Another area we are looking at is as more growers move to straight cutting and the use of desiccants and harvest aids in harvesting canola, we need to have a better understanding of fall emergence timing of cleavers. Growers need to know what effect a pre-harvest application of desiccants or harvest aids might have on cleavers control and for reducing seed production. Moreover, a significant proportion of cleavers populations emerge in the fall and, therefore, management in the fall is key to the sustainable long-term management of cleavers in Western Canada.”
Apr. 14, 2016 - Lentil acres continue to expand across fields throughout Western Canada thanks to increased prices and demand from export markets. In fact, according to Dr. Bert Vandenberg from the University of Saskatchewan Department of Plant Sciences, Crop Development Centre, "growers in Western Canada now supply half of the world's lentils." For growers, one of the largest obstacles in meeting this growing demand for the crop is weeds. "Lentils are poor competitors when it comes to weeds," said Danielle Eastman, Brand Manager, Western Herbicides and Clearfield at BASF Canada. "That is why BASF designed Solo ADV, with reliable control of tough grasses and targeted broadleaf weeds. The new formulation also provides growers with exceptional re-cropping flexibility among the Clearfield system herbicides, particularly for Clearfield lentils. As lentils are sensitive to many herbicides, Eastman says Solo ADV herbicide provides growers with a safe choice for lentils, with the added benefits of exceptional rotational flexibility in a convenient liquid formulation for easy handling and reduced fill-up times, resulting in time saving and peace of mind. "We have had good action with our Solo ADV and in a field of small green lentils," said lentil grower Calvin Watson of Avonlea, Saskatchewan. "It was effective on our mustards and other volunteer weeds like canola that we have treated in the past with Solo, but the ease of use was way better. With Solo ADV we are not having to wait for granulars to dissolve and mixing. Just get in the tank and go. The built-in adjuvant eliminates the need to buy, store and add your own at a later time. For us, the benefits of Solo ADV mean less handling of jugs, less chance to spill, along with more time saved." As lentil acres continue to expand, Eastman encourages growers to maximize the success of their crop with support of the unique benefits of Solo ADV herbicide.
March 14, 2016, Ontario – Mike Cowbrough, OMAFRA weed specilaist, discusses the strengths and weaknessness of two "new" herbicides for 2016 in his podcast. | READ MORE
Reducing potential yield losses at harvest, particularly from pre-harvest shattering and pod drop losses, is a priority when harvesting canola. Whether straight combining or swathing, timing of harvest is proving to be one of the most important factors in reducing the risk and magnitude of yield losses. Researchers at the Indian Head Agricultural Research Foundation (IHARF) in Saskatchewan have wrapped up a four-year study initiated in 2011 to evaluate the relative resistance to pod shatter and pod drop of high-yielding Brassica napus hybrids. The project was conducted at four sites including Indian Head, Melfort, Scott and Swift Current. Researchers evaluated the potential for pod shattering and pod drop of several modern B. napus hybrids across all herbicide systems, including some of the new shatter tolerant varieties. “With the increasing interest in straight combining, we wanted to evaluate a range of cultivars, including some of the newer shatter tolerant varieties, and identify some that may be particularly well suited for straight-combining,” explains Chris Holzapfel, IHARF research manager. “We compared two harvest dates – one at optimal harvest timing and the final harvest completed three to four weeks later – to see what would happen when harvest was delayed due to weather or other factors. We also wanted to quantify the environmental seed loss contributions from pod drop versus pod shattering under a wide range of environmental conditions.” All canola in the study was straight-combined; however catch trays were used to measure and account for any seed losses that occurred prior to the first harvest date. “The major finding was that overall timing of harvest was more important than variety,” says Holzapfel. “Regardless of the variety, environmental and crop conditions was the major determinant of yield losses. As well, pod drop versus pod shatter was an important contributor to yield loss.” The biggest losses on average were from the later harvest date, with pod drop responsible for 43 per cent of the total environmental seed losses with delayed harvest across all hybrids and sites. Losses at delayed harvest ranged from less than five per cent at some sites to more than 50 per cent in one extreme case. At early harvest timing, yield losses from pod drop were typically negligible, averaging 2.5 per cent across all hybrids and sites. Although the evaluation of various cultivars did show some differences, they were not always consistent from site to site. In an effort to summarize the large data set, all of the hybrids evaluated at any given site were ranked for significant differences compared to the top ranking hybrids for each site (i.e. those with the lowest losses). “The best varieties were ranked a 1, with those showing significantly higher losses ranked a 2 and those with the highest losses receiving a ranking of 3,” Holzapfel explains. “Generally the performance of most of the hybrids was similar under favourable conditions; however substantial losses in all cultivars occurred when severe conditions were encountered. For example, in years where conditions were challenging, such as the severe wind events in 2012 and higher than usual sclerotinia incidence, all of the cultivars were impacted and there were severe losses in all treatments, in some cases more than 50 per cent losses. Hybrids specifically bred for improved shatter tolerance (i.e. L140P and 45H32) were introduced to the study in 2013 and, while overall losses were lower in the latter two years of the study, these hybrids did perform consistently well and can be expected to reduce the risk of yield loss with delayed harvest or severe weather.” Timing of harvest is important to minimize losses, so in situations where there is quite a bit of variability in the field, growers may want to consider a pre-harvest treatment, although it’s not always necessary. “One of the lessons learned over the years is to be patient, don’t go in too early,” Holzapfel says. “That said, once the canola is ready, harvesting it as soon as possible needs to be a priority to prevent losses. And there is no way around getting into the field and assessing the colour change throughout, not just from the edge of the field. There can also be differences in colour change and varieties from year to year – sometimes the pods will turn but the seeds can still be green; in others there will be seed colour change, but relatively green pods.” The timing for glyphosate application in Liberty Link canola for straight cutting or swathing is at 50 to 60 per cent colour change. In all systems, the timing of application for desiccant products is at 80 to 90 per cent colour change. Holzapfel adds when there is quite a variation in canola staging, like we are seeing in 2015, assessing harvest timing gets more difficult and can be tricky. “Thin stands may be well suited to straight cutting, and although there may be some losses, there will also be losses from swathing, so there is no easy solution.” Both systems, whether swathing or straight-combining, have risks, with timing of harvest the most important management factor. Recent research at the University of Saskatchewan on commercial farms showed that total seed losses (environmental + header + threshing) for swathed and straight-combined canola were equal and ~10 per cent on average. “Swathing too early results in significant yield loss due to smaller seeds and can lead to higher green seed counts,” Holzapfel explains. “Swathing too late results in yield loss due to pod shatter. Similar to straight-combining, the risk of environmental and header losses increase over time as canola swaths remain in the field, but for straight-cutting, harvest timing is usually more critical than with swathing. Therefore, growers should limit straight-cut acres to what is easily manageable to gain experience and confidence in the practice.” Overall, the project results indicate all hybrids evaluated could be straight-combined successfully provided that harvest was completed in a reasonably timely manner. Other factors such as overall yield potential, days to maturity, standability and herbicide system are still the most important factors to consider when choosing a canola hybrid with the intention of straight-combining. Hybrids with improved pod shatter tolerance lengthen the window for straight-combining and reduce the overall risk of yield loss. There are new shatter tolerant varieties coming on the market for 2016, and Holzapfel expects that more varieties will continue to be released in the future. “We know that most existing equipment will work adequately, including draper, rigid and flex headers,” Holzapfel says. “Header extensions significantly reduce header losses and are a good option for straight-combining large acres of canola, and headers with variable knife position should provide similar benefits. We are collaborating on another three-year project led by Nathan Gregg of PAMI that started in 2014 to evaluate the performance of commercial straight-cut headers for canola using full-scale machinery and large plots at Swift Current, Indian Head and Watrous. Harvest treatments will be evaluated on two varieties, a standard canola variety InVigor L130 and a shatter resistant variety InVigor L140P.” The final report and results will be available in 2016.
'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