At the University of Georgia, a team of researchers is developing a robotic system of all-terrain rovers and unmanned aerial drones that can more quickly and accurately gather and analyze data on the physical characteristics of crops, including their growth patterns, stress tolerance and general health. This information is vital for scientists who are working to increase agricultural production in a time of rapid population growth.
While scientists can gather data on plant characteristics now, the process is expensive and painstakingly slow, as researchers must manually record data one plant at a time. But the team of robots developed by Li and his collaborators will one day allow researchers to compile data on entire fields of crops throughout the growing season.
The project addresses a major bottleneck that's holding up plant genetics research, said Andrew Paterson, a co-principal investigator. Paterson, a world leader in the mapping and sequencing of flowering-plant genomes, is a Regents Professor in UGA's College of Agricultural and Environmental Sciences and Franklin College of Arts and Sciences.
"The robots offer us not only the means to more efficiently do what we already do, but also the means to gain information that is presently beyond our reach," he said. "For example, by measuring plant height at weekly intervals instead of just once at the end of the season, we can learn about how different genotypes respond to specific environmental parameters, such as rainfall." | READ MORE
The move to a single wheat check-off is part of AWC’s plan to assume the funding obligations of the WCD that will sunset on July 31, 2017. In this model, AWC will assume a greater role in funding new wheat varieties and will maintain current funding commitments for the Canadian International Grains Institute (Cigi), which contributes to market support, education and testing services to meet the needs of Canada’s key customers. AWC will also maintain its current portfolio of programming.
The WCD check-off is currently applied to all sales of wheat delivered to licensed grain buyers in Western Canada. AWC’s western Canadian counterparts, Saskatchewan Wheat Development Commission and the Manitoba Wheat and Barley Growers Association, will also transition to a single check-off. The three commissions recently signed a Memorandum of Understanding to absorb the responsibilities and funding obligations of the WCD.
Prior to the vote on the new check-off at its annual general meemting, AWC administered a survey of Alberta’s wheat farmers to garner producer perceptions on the new check-off value. Survey results indicated 75 percent either strongly or somewhat support the proposed $1.09 check-off. Following approval from the provincial government, AWC will work with grain companies to implement the new service charge amount.
Learn more at albertawheat.com
While lingering cool soil temperatures slowed development of the earliest planted corn, emergence was generally good for most fields. With the lack of rainfall in May, corn that had been planted when parts of fields were not quite fit or had not been fully planted into moisture may have struggled to emerge or emerged late. While generally minor overall, this resulted in variability in some fields. Some growers on heavier soils reported emergence issues following the cool weather and rainfall of May 14-15th. A small amount of replanting was reported to have occurred.
The annual OMAFRA Pre-Sidedress-Nitrate-Test (PSNT) survey was conducted at the V3-V4 stage on June 6-7th. With an overall average soil nitrate concentration of 11.2 ppm, levels were average to slightly higher than average. Given the lack of rainfall and low potential for soil saturation during May and June, nitrate losses from leaching or denitrification were unlikely. Below average precipitation in June maintained a wide window for weed control and sidedress nitrogen applications. With the exception of some moisture stress appearing on soils with poor water holding capacity in the drier parts of the province, the corn crop generally looked good and uniform through the end of June.
While some parts of the province received rain in July, many areas continued to be below normal, particularly the Bruce-Grey, Niagara and Central Ontario regions. Fields or parts of fields in these regions were beginning to show signs of moisture stress as corn leaves would wrap. There were some concerns as corn entered the moisture-sensitive tassel and pollination stages during the hot and dry conditions around the week of July 18. Some localized areas received thunderstorm related precipitation around this period.
During grain fill, there were reports of “tip-back” where several rows on the cob tips failed to pollinate and silks remained green. Warm temperatures continued to push crop development. As corn continued the grain filling process, significant rainfall events started to occur during August, with monthly precipitation totals ranging between 100-200 per cent of normal for large portions of the province. Despite this, leaf diseases, where present, typically remained at low levels. Between timely planting and above average heat unit accumulation, there were few concerns about crop maturity as August came to a close.
Silage harvest started in earnest in many areas during the week of September 12, with the exception of some early harvesting of moisture stressed crops. September remained generally dry, which resulted in good silage harvest conditions. Some reported whole plant moisture being drier than what had been anticipated at the start of harvest. Yields were reported to be below average in areas with little rainfall and on soils with poor water holding capacity, while yields in other areas were reported to be average. Lab analysis results suggested vomitoxin levels in silage were higher than normal.
The annual OMAFRA grain corn vomitoxin survey was conducted from September 23 to 30th. The survey indicated elevated vomitoxin levels with 26 per cent of samples testing above two ppm. Long-term averages for this category run between five and 10 per cent, suggesting some extra monitoring for grain management and feeding may have been required in 2016. Risks may have been elevated from the wet and humid conditions that persisted from August to early September. Poorer pollination of ear tips which resulted in silks remaining green and husk tips that tended to remain tight may have also contributed to this. Western bean cutworm feeding that opened husks for mould establishment was prevalent in many areas as well. The incidence of samples testing higher for vomitoxin decreased east of Toronto.
As the growing season came to a close, heat unit accumulation ranged from average to 100-200 Crop Heat Units (CHU) higher than normal. Coupled with dry weather, corn harvest started early with some combining beginning as early as the last week of September. Harvest started in earnest around October 15, and progressed quickly as dry conditions prevailed for most of the province, resulting in a wide harvest window. Most growers reported moisture levels lower than what was typical for the time of year, and excellent test weights. With the exception of some localized pockets where soybean harvest was delayed, harvest was wrapping up in most areas by the end of the first week of November. Many growers reported yields that were above expectations considering the hot, dry growing season, with the exception of those on soils with poor water holding capacity, or regions which received well below average precipitation. As of December 14, Agricorp corn yields have been reported on 78 per cent of insured acres with an average yield of 167 bu/ac. This compares well to the 10 year average yield of 167 bu/ac for those reported acres.
“This year’s harvest has been a long, drawn out affair, filled with frustration and disappointment,” said Harry Brook, crop specialist, AF, in a press release. “Many producers still have crop left to be harvested or are taking it off wet, with grain being binned or bagged or piled at unheard of moisture levels. These crops cannot be left out in the cold for extended periods of time unattended.”
Once the crop is harvested and in storage, the excess moisture must be dealt with as soon as possible. “If you don’t have ready access to a grain dryer or have aeration for your bins, you must closely monitor the grain or oilseed for signs of heating. If you see signs that there is heating, you will need to cool the grain by circulating the grain out of and back into the bin. Depending on bin or pile size, this may have to be done fairly frequently.”
Brook has a caution for producers who are using grain bags for short term storage. “Remember that very damp or wet grain in a bag will start to mould. Some moulds will grow at cold temperatures and losses can be high. If bags are used for wet grain storage it should only be short term until crop drying occurs and close monitoring can again begin.”
When drying grain, there are maximum temperatures that should be used on the various crops. “There are tables that outline the maximum temperatures to be used to dry grain. Don’t exceed those maximum drying temperatures to avoid quality losses. With a large amount of moisture to be removed or a big seed, multiple passes of drying and cooling will be needed. In large seed like fababeans, drying might take three or four cycles to bring it down to safe storage levels. The cooling is required to let the moisture content in the seed equalize.”
If there is aeration, some supplemental heat can be used to help dry down the crop. However, Brook said, in this case smaller bins will be more useful than large bins. “To make this work, the fan has to have sufficient air flow to provide at least 0.5 cfm/bushel before adding the supplemental heat. Success will depend on the cleanliness of the grain and, even then, a load or two will have to be circulated out of the bin and back in to help equalize moistures and prevent dry and wet channels in the grain.”
Brook recommends restricting the air temperature increase to 10 C or less as higher temperatures can reduce efficiency and increase the chances of over-drying. For every 10 C increase in air temperature, the relative humidity is halved.
“If you have crop that is damp or wet, monitor it closely for signs of heating and, if it occurs, take the appropriate measures to retain the value of the crop. It is too costly to do otherwise.”
Canola acres in Ontario were higher in 2016 than they were in 2015. The total number of insured canola acres in 2016 was just shy of 30,000 acres, compared to 25,000 acres in 2015.
With a drier than normal spring throughout much of the province, canola growers were able to plant early. In the southern half of Ontario a majority of the acres were planted in the last week of April and first half of May. Rain in mid-May meant that some canola was planted towards the end of the month. Spring conditions in northeastern Ontario were not much different than that further south, so planting was relatively early in Temiskaming and Nipissing as well. Further north, towards Cochrane, wet weather pushed planting back into June.
Early planted fields got off to a great start; they emerged within a week and moved quickly through early growth stages. There were pockets of frost in early May but it did not cause significant issues. Most herbicide was applied by the first week of June, and the majority of the crop was beyond 3 leaf stage by early June. Early planted fields began blooming in the second week of June. Dry weather and high day and night time temperatures during July and August caused some stress on canola plants, however, yield results and reports from farmers indicate the stress was not a significant issue.
Insects and diseases
There was a limited amount of spraying for flea beetle in 2016. Seed treatments were effective in protecting plants from feeding during early growth stages. The good planting conditions and warm spring allowed the crop to advance quickly through early growth stages, minimizing economic damage normally caused by flea beetles.
Fast, early growth is one of the best ways to avoid significant swede midge damage so the good spring conditions contributed to reduced swede midge damage. By the June 1, swede midge had been detected in Wellington, Renfrew and Grey counties and had reached threshold numbers in the New Liskeard area. Overall, fewer pheromone traps were set this year and data was not collected across the province, making it difficult to judge the actual state of swede midge populations. The need to spray across all counties was varied. Some had pressure that warranted spraying during vulnerable crop growth stages prior to bolting, and there were relatively high rates of success in controlling the pest. Much of the early planted crop was able to quickly grow past susceptible stages.
Spraying for swede midge did occur in northeastern Ontario but not to the extent of years past. A number of fields were planted in areas where there was no recent history of canola, reducing the risk of swede midge damage. In the majority of fields where there was significant swede midge pressure the crop did bolt but side branching was impacted. Swede midge continues to be monitored on fields in north eastern Ontario where there were high populations in years past. In early June, one field where canola had not been planted since 2013, approximately 500 male swede midges were captured in the first 24 hours after the trap was set. Growers recognize they have not entirely beaten the pest but have been able to manage it and keep damage levels low this season.
In the southern half of Ontario, much of the crop bolted before there was significant swede midge pressure, so major economic damage was avoided. There were reports of swede midge at threshold in the Renfrew area during early growth stages, and those fields were sprayed. Many growers saw increasing trap counts during and after bolting and had to make a decision as to the value of spraying. Many acres through Bruce County, particularly those planted later, were sprayed once for swede midge and the fields had very limited damage in the end.
Cabbage seedpod weevil (CSW) was identified at threshold levels in Bruce and Grey counties and some fields were sprayed. However, it is unclear as to whether the timing of the spray was at the appropriate crop growth stage. CSW will feed on flower buds to some extent, but the critical control period is when adults are present to lay eggs in newly forming pods (larvae feed inside the pods later on). Spraying primarily occurred prior to 10 to 20 per cent bloom, but likely could have been delayed until early pod formation and combined with foliar fungicides. Fortunately, a new population of CSW did not move in during later flowering stages and notable CSW damage was not found.
Because of the dry field conditions and lack of rain in the forecast, risk of white mould was very low during mid-bloom. Many farmers opted to skip the fungicide application, and white mould was not reported.
Quality and yield
Somewhat surprisingly, there were no reports of brown or heated seed in this dry, warm season. Quality was good overall, and green seed was not reported. Crushers have indicated that oil content was higher than last year, but is not as high as the western crop. The harvested seed did not need to be dried; in fact some was as low as six to seven per cent moisture.
Canola yields across Ontario were good for the most part. Many have stated the crop was better than expected and that yields were consistent and strong. However, average yields reported by Agricorp indicate that in general, yields in southern and eastern Ontario were lower than last year, and yields in northern and northeastern Ontario were higher than last year. The average yield for the province, based on acres under production insurance, is 2,095 lb/ac compared to 2,341 lb/ac in 2015.
In Cochrane, Rainy River and Thunder Bay regions combined (2,411 ac), the average canola yield was 2,256 lb/ac. In Manitoulin, Sudbury and Temiskaming regions combined (3,594 ac), yields averaged 2,006 lb/ac which is higher than last year (approximately 1,900 lb/ac). Yields in Nipissing were strong at an average of 2,719 lb/ac. Harvest generally wrapped up in these areas during the last week of September.
Average yields in Bruce (1,820 lb/ac), Grey (2,058 lb/ac) and Wellington (2,322 lb/ac) counties are lower than last year and canola acreage across these three counties was 8,572 ac compared to 7,775 ac in 2015. All other canola growing regions between Huron and York averaged around 2,200 lb/ac. The average yield across Kawartha Lakes, Northumberland, Peterborough and Prince Edward counties was just 1,289 lb/ac. From Lennox and Addington and Renfrew through to the easternmost counties, canola yields averaged 1,967 lb/ac. The majority of canola in the southern half of Ontario was harvested by the first week of September.
Initiated in 2014, preliminary results from the first two years of the project are showing similar trends, which researchers expect to be able to confirm at the end of the 2016 crop season. An economic analysis of the three-year project will also provide additional information to support decision-making.
The project includes three study locations – Indian Head, Swift Current and Humboldt – and uses the same protocols and headers at each location. Researchers have been able to refine their testing methods in the first two years, which will strengthen the information collected at the end of the project. The project also compared two types of canola varieties, a standard hybrid variety (InVigor L130) and two shatter resistant varieties (InVigor L140P and Dekalb 75-65 RR). Factors such as yield, header loss and loss location, environmental shatter loss and various quality components are measured.
“The results from the first two years of the project are showing very similar trends,” explains Nathan Gregg, project manager with the Prairie Agricultural Machinery Institute (PAMI). “Although all of the headers performed well, the Varifeed with the extendable cutter bar does show some marginal gains in loss retention. It seems to be able to retain more of the shatter loss that occurs with all of the headers.” Gregg adds that from the observations so far the extendable cutter bar allows it to go further forward, which in theory helps to retain losses from the reel. It also provides for smoother crop flow sideways to the centre of the header and then into the feeder house. This smoother crop flow means less violence and less shattering occurring in the conveyance process.
“The Varifeed was also a bit more operator friendly and is a little easier to run. The extendable cutter bar is a bit more forgiving and can just go ahead/back to match the crop canopy conditions with the push of a button in the cab. Although the Varifeed provides some advantages, it doesn’t mean the other headers don’t work well. The draper does a good job, but it does take more attention to detail as far as reel position and reel speed to match to the crop canopy. However, the draper header with its ground-following floatation system performed a bit better under lodged crop conditions.”
A key objective of the project is to try and identify the source and location of the header losses. In 2016, researchers increased the number of sample pans, which are placed in the crop across the width of the header and into the zone just beyond the header into the adjacent crop. “So far, the preliminary results show the higher proportion of losses are at the perimeter of the header, with another spike of losses at the centre of the feeder house,” says Gregg. “The pattern of losses is similar for all of the headers compared, although there are some differences in the degree of loss. These results are not surprising and are similar to research conducted elsewhere in Sweden and in other regions.”
With the higher shatter losses concentrated at the perimeter of the header, researchers also wanted to compare losses of different dividers. Powered side cutters, including a vertical knife and a rotary knife were compared with regular passive end point dividers. Overall, the rotary knife had the highest losses of any configuration. The losses were not only higher but also higher for a wider zone (more than one foot at the point). The losses with the vertical knife were lower, with the regular passive divider showing some of the least loss. Researchers are not sure if the results are universal, but under the harvest conditions in the locations tested, the results from the divider losses were fairly consistent.
“One caveat to the findings is the question of why power dividers are being used in the first place,” explains Gregg. “Generally, power dividers are used on swathers for example to allow forward progress without the crop balling up and catching on the crop divider. However, in a straight cut situation, if conditions are right and crop material is drier, power dividers may not be necessary for forward movement. Overall, the passive divider provided a smooth sleek transition and the potential for lower losses in the conditions we have seen so far. Therefore, a tip for growers who are straight cutting and trying to use the header they have, it may be worth some time investment to install cardboard and duct tape, or whatever, to help make the transition at the divider point and around the edge of the header smoother.”
The preliminary results of the variety trial comparisons were similar after the first two years of the project. Researchers will be able to provide better details after the 2016 growing season results are in and an economic analysis is completed. “In conventional hybrid canola, the standard control swath and combine treatment actually yielded the highest,” Gregg says. “The losses in the straight cut treatments were a bit higher and there were some additional losses to wind. However, the shatter resistant varieties performed well across all treatments, with the straight cut treatments yielding the highest. We need to complete the economics, however, the results so far indicate that investing in some sort of shatter resistant canola variety would be a very good consideration for growers who are planning to straight cut.”
“Although header choice plays a role in minimizing losses, other management decisions, choice of variety and harvest timing may hold more potential to impact yield than specific equipment,” adds Gregg. “As the practice of straight cutting canola gains traction, some growers will move to a specific header for the task, but in the meantime we are not seeing anything that suggests they need to rush out and do that immediately. There are several factors that come together at harvest and we are trying to look at some of those. We have another project underway looking at crop maturity and harvest timing and the potential of using desiccation for straight cutting, and the impact these may have on combine performance (settings, fuel use, productivity, etc). When straight cutting, growers need to be patient and wait for the crop to be ready. In the future desiccation may be one of the tools that becomes more important.”
The project is jointly funded by SaskCanola, Saskatchewan Ministry of Agriculture and the Canada-Saskatchewan Growing Forward II Bilateral Agreement and the Western Grains Research Foundation.
Forage production in 2016 was challenging as the cool spring delayed early growth and was followed by a hot, dry summer before rains returned in August. While hay inventories are below average, most of the hay harvested was high quality. This year has seen an increase use of cover crops for emergency forage and fall grazing. More corn has been harvested for silage than originally planned. Farms that can utilize straw or corn stover are doing so in order to extend stored feed.
Alfalfa winterkill and stand vigour
In 2016, there was very little winterkill observed across the province, mainly due to a very mild winter. The cool weather in March, April and into May reduced alfalfa growth and delayed first cut by approximately seven to 10 days. This fall saw a lot of fields cut during the critical fall rest period. Depending on when the killing frost comes, fields that were harvested up to six weeks prior are at an increased risk of winterkil. Other risk factors such as three-year-old (or older) stands, low potassium or pH, poor soil drainage, fields that had disease or insect issues, weather, ponding, and lack of snow cover, can increase the risk of winterkill and fields with multiple risk factors should be monitored in the spring.
Fertility levels on many fields continue to cause yield drag. Phosphorus levels less than 12ppm and potassium levels less than 120ppm can significantly lower yields. Sulphur has continued to show up in plant tissue tests as a yield limiting nutrient. If plant tissue tests were completed when the alfalfa was at normal mowing height and at the late bud stage, sulphur levels under 0.22 per cent, indicate a deficiency. A soil sampling program should be implemented to monitor soil fertility levels. Fall applications of fertilizer or manure can take place up until the ground freezes or there is snow cover, but are most beneficial if applied directly after the final cut of forage.
A dry spring provided the opportunity for new seedings to be planted into good soil conditions. However, lack of rainfall resulted in variable establishment, especially where packing for good seed-to-soil contact was insufficient. Summer seedings completed during optimum seeding dates in August appear to have been very successful as there was adequate moisture. Summer seedings do not have the yield drag associated with first year forages and will produce to their potential next year.
First-cut yields and quality
First-cut yields were fairly average across southern Ontario. Due to the cool dry weather in April and May, alfalfa maturity was delayed by seven to 10 days. First-cut quality was excellent. The dry weather provided the opportunity to cut at the proper maturity and the majority of the first cut was harvested without rain and at the correct moisture levels.
Second, third and fourth cuts
Across most of southern Ontario, second- and third-cut yields were extremely variable depending upon precipitation which varied widely across the province but were typically below average or non-existent. Quality of hay was excellent, as rainfall did not impact harvest timing and the hay was taken off at the correct moisture. When alfalfa was allowed to go to full bloom, quality declined and yield did not significantly increase from 10 per cent bloom. After the rains returned in August, there were a lot of fields harvested one more time, and many of these were harvested during the critical fall harvest period as the need for high quality forage outweighed the risk. This cut had excellent yields for the time of year and made high-quality forage.
This spring saw farmers having winter rye for grazing, and animals were out on those fields up to two weeks before their permanent pastures were ready for grazing. Pasture regrowth was slow this year due to the hot and dry weather and the benefits of rotational grazing were very visible as they managed to graze longer before the pastures dried out. Pastures where the growth left behind was still seven to 10 cm (three to four inches) when animals were moved after one to three days saw more regrowth over the course of the year and less hay fed. In order to accomplish this, the rest period during the summer was 45 days or more. Farms on permanent pastures were supplementing feed for up to 12 weeks while intensively managed rotationally grazed pasture were supplementing hay for two to three weeks. During July, there were reports of water holes drying up and cattle on pasture requiring additional water. Cover crops are being utilized to extend the grazing system into the fall and corn stalks are providing a forage source for a growing number of producers who prefer to graze. Grazing animals on corn stubble reduces feed costs, breaks down the stover and reduces the amount of hay required over the winter. Corn stalks can provide an excellent fibre source for non-lactating animals.
Corn silage production was very variable across the province, from very low to average yields. The grain content of the corn silage was also variable; with starch levels running from five per cent to 35 per cent (28 per cent is normal). Silage with low starch levels has low grain content and will require additional supplementation. Silage with high starch levels is typically associated with lower yields or a high grain:stover ratio and needs to be managed to avoid acidosis. In areas short of hay, additional acres of corn were harvested for silage rather than grain.
With the reduced forage yields, there has been an increased interest in the use of cover crops for emergency forage as haylage, balage and grazing. The most popular cover crops are small grains (generally oats, but also barley and triticale) or a small grain and pea mixture. Peas increase the protein and energy content of the feed. Italian ryegrass was also used as it produces a higher quality feed than small grains and can be harvested once in the fall and again in the spring. Turnips and brassicas were added to mixtures of cover cops that were destined to be grazed in the fall.
Fall rye and winter triticale are also seeing a boost in acres this fall as producers are looking for an early season forage. Fall rye and winter triticale can be planted following corn silage, grain corn or soybeans. They can be pastured in mid-to-late April if they are planted on dry ground, or cut for hay around mid-May.
Harvest began the previous week in parts of western and central Ontario. Yield reports have been variable ranging from single digit to upper 60 bushels per acre (bu/ac). Low yield reports, not surprisingly, appear to correspond closely with the precipitation received throughout the season. However, some producers have been pleasantly surprised with how well soybeans have yielded even with less than ideal amounts of precipitation. Seed size appears to be smaller than normal, although quality has been good to date. Although the presence of green stems is more prominent this year than others, it has not seemed to significantly reduce harvesting efficiency. It is estimated that between 40 and 45 per cent of the provincial acreage has been harvested.
An early soybean harvest for some has provided an opportunity to plant wheat into very nice conditions with emergence occurring in less than a week. A reminder that a proper planting depth of one inch is extremely important and planting too shallow is often the cause of stand issues the following spring as a result of frost heave and winterkill. Regardless of planting date, seed placed starter fertilizer provides an additional eight bu/ac of grain yield. Seedling Canada fleabane, which in many cases is glyphosate resistant, has already emerged, and there is an opportunity to apply Eragon pre-plant or pre-emergence to manage this problematic weed. Otherwise, a post-emergence herbicide application will be necessary to control Canada fleabane in winter wheat. If chess (aka cheat grass) or downy brome has been a problem in your cereal fields in the past, there are now two options to deal with these grassy weed species. The first is called Focus and must be applied pre-plant or pre-emergence to the wheat crop (and before weed emergence), while the second is called Simplicity and can be applied post-emergence to both crop and weed in the spring.
A very small amount of corn has been harvested although grain moisture is dryer than it is normally at this time of year, prompting some producers to start taking off high-moisture corn especially when rain has delayed soybean harvest. A significant number of producers and agronomists have noticed western bean cutworm (WBC) damage in mature cobs. When damage is significant, consider harvesting early to stop mould growth. Adjust your combine to discard lightweight mouldy kernels and dry mouldy corn as soon as possible. Normally hot, dry conditions are not good environmental conditions for ear mould fungi like Fusarium graminearum (Gibberella), and Fusarium verticillioides. However, rains or humid conditions along with hybrid susceptibility, incomplete pollination, and cob damage by WBC has resulted in pockets of infection in some areas of the province that could result in mycotoxins being produced, especially deoxynivalenol (DON or vomitoxin). Growers should be assessing fields for ear mould infection and harvest fields first with 10 per cent or more ear mould.
Harvest progress ranges anywhere from 50 to 80 per cent done. The least amount of harvest progress has been made with Adzuki beans since they mature later than other market classes, while significantly more progress has been made harvesting cranberry and white beans. As with many crops in 2016, dry conditions have impacted grain yield. Harvest yield reports have been variable with the larger seeded coloured beans yielding average to below average. While white bean yield reports have been average to below average. Overall bean quality has been good with seed size being somewhat smaller than normal.
As corn producers plan for harvest, they should be accessing their fields for stalk rot and ear moulds, reminds the OMAFRA Field Crop team. The distribution and prevalence of these diseases vary from year to year but they are present every year, especially when the crop is under stress (water stress, insect feeding, etc.). It goes without saying that this year was very stressful and in many cases, corn plants had to endure not one stress but multiple stresses and we are observing ear mould infections (Gibberella and Fusarium primarily) in many fields across the province. They range from light to significant levels therefore, in order to manage and minimize the effects of these ear rot diseases, it is critical to assess fields before harvest. Growers should assess fields each year, because these pre-harvest assessments can alert them to potential problems and provide time for livestock producers for example, to segregate, obtain alternative grain, or hold onto stored corn from the previous year.
Scouting practices are similar for all corn ear rots. Begin scouting fields at late dent stage to determine their presence and severity. When scouting, randomly select plants and pull back the husk to examine the entire ear. A quick method is to select 100 plants across the field (20 ears each from five different areas). For each ear, be sure to peel back the husks and examine the entire ear. Fields with 10 per cent of ears having significant mould growth should be harvested sooner than later.
Leaving diseased grain in the field allows the ear rot fungi to keep growing, which will increase the risk of mouldy grain and mycotoxin contamination. Most ear rot fungi continue to grow (and, if applicable, produce mycotoxins) until the grain has less than 15 per cent moisture. In severely infected fields, it may be worthwhile to harvest grain at higher moisture and then dry it to less than 15 per cent to minimize further mycotoxin accumulation.
Preventing ear rots and mould is difficult since weather conditions are critical to disease development. Although some tolerant hybrids are available, none have complete resistance. Crop rotation can reduce the incidence of Diplodia ear rot. Cultural practices have been shown to have limited success in preventing ear and kernel rots. Minimize these diseases through timely harvest and proper drying and storage.
When ear rot is present, the following storage and feeding precautions are advisable:
- Harvest as early as possible.
- If bird damage is evident, harvest outside damaged rows separately. Keep and handle the grain from these rows separately.
- Adjust harvest equipment to minimize damage to corn. Clean corn thoroughly to remove pieces of cob, small kernels and red dog.
- Cool the grain after drying.
- Clean bins before storing new grain.
- Check stored grain often for temperature, wet spots, insects and mould growth.
- Control storage insects.
- Exercise caution in feeding mouldy corn to livestock, especially to hogs. Pink or reddish moulds are particularly harmful. Suspect samples should be tested for toxins.
Gibberella ear rot: The most common and important ear mould in Ontario is Gibberella zeae which is the sexual reproductive stage of Fusarium graminearium. This fungus not only infects corn, but also small grains such as wheat, and can survive on soybean roots. In most cases, Gibberella begins at the ear tip and works its way down the ear. Also, the husks from infected ears are often tightly adhered to the ear. Although the fungus can produce a white-coloured mould, which makes it difficult to tell apart from Fusarium kernel rot, the two can be distinguished easily when Gibberella produces its characteristic red or pink colour mould. Infection begins through the silk channel and thus, in most cases starts at the ear tip and works its way down the ear. In severe cases, most of the ear may be covered with mould growth. Corn silks are most susceptible two to 10 days after initiation. Warm and wet weather during this period is ideal for infection.
Fusarium kernel rot: Unlike Gibberella, Fusarium infected kernels are often scattered around the cob amongst healthy looking kernels or on kernels that have been damaged by corn borer or bird feeding for example. Fusarium infection produces a white to pink or salmon-coloured mould. A "white streaking" or "star-bursting" can be seen on the infected kernel surface. Although many Fusarium species may be responsible for these symptoms, the primary species we are concerned about in Ontario is Fusarium verticillioides (formerly Fusarium moniliforme). Fusarium survives in corn debris. The significance of this fungus is that it produces a toxin called fumonisin that has been shown to cause cancer in humans. The environmental conditions that favour disease development are warm, wet weather, two to three weeks after silking.
Diplodia ear rot: The characteristic ear symptom of Stenocarpella maydis and S. macrospora infection is a white mould that begins at the base of the ear and will eventually cover and rot the entire ear. Mould growth can also occur on the outer husk which has small black bumps (pycnidia) embedded in the mould. These reproductive structures are where new spores are produced. Pycnidia (the small, black, spore-producing structures of the fungus) overwinter on corn residue and are the source of infection for the subsequent corn crop. Dry weather before silking, immediately followed by wet conditions, favour Diplodia infection.
Penicillium ear rot: Penicillium rot (Penicillium oxalicum) produces a light blue-green powdery mould which grows between the kernels and cob/husk surface. Infected kernels could become bleached or streaked. Penicillium ear rot can be a serious problem if corn is stored at high moisture levels (greater than 18 per cent).
Table 1. Common ear rots and moulds that occur in Ontario and the primary mycotoxins they produce.
||Signs and symptoms|
|Aspergillus||Aflatoxin||Hot, dry||Olive green spores on ear|
Moderate to warm temperatures during silking,
wet periods prior to harvest
|White to purple mold, scattered across ear;
Starburst pattern in kernels
|Gibberella||Deoxynivalenol (vomitoxin) and zearalenone||Cool, wet weather||Pink to white mycelial growth|
|Diplodia||None currently known in U.S. and Canada||Moderate temperatures and wet during silking||White mycelial growth on ear and husk; black pycnidia in cob|
|Penicillium||Ochratoxin (only some species)||Wet, humid conditions post grain-fill||Blue-gray fungal spores|
|Nigrospora||None||Damaged corn||Black spores, grey mycelia, shredding cob|
|Cladosporium||None||Wet weather near harvest||Dark-green to black kernels|
|Trichoderma||T-2 (only some species)||Damaged corn||Blue-green spores growing in and on kernels; may cause sprouting|
More information can be found in OMAFRA’s Field Crop Agronomy Guide – Publication 811, or Crop Protection Network Publication “Corn Management Disease Series – Ear Rots” at CropProtectionNetwork.org.
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