Seed Placed Fertilizer – Safe Rates

A reminder that if seedbeds turn dry, the safety margin shrinks when applying seed placed fertilizer.  Seedburn can result from ammonia toxicity and/or salt content of fertilizers.

For nitrogen, our Soil Fertility Guide provided safe guidelines for seed placed urea on cereals and canola across a range of soil types and seed-fertilizer configurations.  With the increased popularity of narrow seed and fertilizer spreads with disk drills, the safe rates are reduced.  For example, safe urea rates for cereals vary from 10 to 25 lb N/ac going from sand to clay soil using disk openers on 6” row spacing.  These guidelines are for moist soil and should be reduced by 50% if seedbed moisture is lower when weather is hot and windy.

The safe rates of seed placed phosphorus depends on the crop, with cereals being quite tolerant compared to soybeans, dry beans and canola.  With a disk drill as described above, cereals can tolerate 50 to 60 lb P2O5/ac as mono ammonium phosphate while rates would be 20 lbs/ac for canola and less for beans.   If there greater seedbed utilization (i.e. narrower rows or a wider seedrow with less fertilizer concentration) rates could be more liberal.

More on these safe rates of fertilizer is posted on Manitoba Agriculture’s website at: http://www.gov.mb.ca/agriculture/crops/soil-fertility/print,safe-rates-of-seed-placed-phosphorus-for-manitoba–narrow-row-and-row-crops.html

 

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When Should I Start Planting Corn in 2017?

Is it better to plant into cold soils realizing the seed is going to sit there until the soil warms up? Or should corn be planted when soil temperatures are warmer and approaching 10°C?

Planting into cold soils.  Early planting is a component of successful corn production in Manitoba, to maximize yield, obtain high quality and low percent kernel moisture at harvest (which will decrease drying costs), and to ensure the crop is mature before fall frosts.

Cooler soil temperatures can delay the crop’s emergence. Wet conditions added to cold soil temperatures can favor soil pathogen development, increasing seedling disease risks in both germinating seeds and young seedlings. When planting early in the season or when the soil is cold, a planting rate 10% higher than the desired final stand should be considered to compensate for possible increased seedling mortality. As well, when planting into cool soils, other seeding management becomes important, such as good seedbed condition (good soil to seed contact) and planting operations (including planting depth).

For more complete information, visit Manitoba Corn Growers website at http://manitobacorn.ca/plant-corn-wait-warmer-soils/

 

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Spring Options for Applying Nitrogen Fertilizer in 2017

With the wet conditions and delayed harvest experienced in parts of Manitoba in fall 2016, very few farmers were able to complete their fall fertilization program.  Since early seeding is important for optimizing crop yield, producers will be looking for ways to apply their N requirements efficiently without delaying the seeding operation.  In addition, soil reserves of N are variable and margins between crop revenue and input costs are modest; therefore, optimizing nitrogen fertilizer use efficiency is important.  To achieve these objectives for a spring fertilization program will require use of a 4R nutrient stewardship strategy:  applying the right rate of the right fertilizer source, with the right placement and at the right time to minimize losses of fertilizer N to the environment and optimize the crop’s access to the fertilizer.

For more detailed information, see the on-line factsheet at http://www.gov.mb.ca/agriculture/crops/seasonal-reports/pubs/spring-n-options-17.pdf

Submitted by John Heard, Crop Nutrition Specialist, MB Ag

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Will I be able to improve the grade of my grain by using gravity tables and colour sorters?

Gravity tables and colour sorters have been shown to be an effective way of sorting out fusarium-damaged kernels (FDK) if the grower has the time and money to spend on the method. Gravity tables remove kernels based on density and are effective at removing heavily infected seeds, but can also result in the loss of healthy seed. Optical sorters remove kernels based on visual differences, but the process can be time-consuming and is more suited to hard wheat than soft wheat. Additionally, fusarium-damaged barley and oat do not show significant shrivelling and are not likely to be removed by equipment sorting by density, weight or colour.

It is important to remember that removing FDK (i.e. visibly infected kernels) from a grain sample does not mean that the grain is free of DON, the toxin produced by Fusarium graminearum. The relationship between FDK and DON varies and in years where infection occurs late in anthesis (or even after anthesis), visual symptoms are not always apparent whereas DON levels can still be elevated. While the Canadian Grain Commission grades wheat based on percent FDK, some markets are interested in DON levels. It is important to discuss with grain buyers and/or elevators their guidelines regarding FDK and DON. It is also recommended that growers test their grain for DON to best determine how to market it.

There is newer technology available that sorts grain based on chemical composition using near infrared transmission (NIR). This method is more effective at reducing DON levels because it is not only dependent on visual symptoms on the kernel. The machinery required to sort grain using NIR can be quite expensive to purchase, but is relatively inexpensive to run. For more information on this technology please refer to http://bomill.com/products/.

 

Submitted by

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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Economics & Agronomics – Crop Management Decisions Need Both!

It’s an obvious statement to say successful farm management decisions need both agronomic and economic considerations. Farmers weigh out input cost versus the benefit to yield and quality of grain before making the decisions to buy and use new or additional products.

 Agronomy and economic crop management goes much beyond inputs. Consideration of crop rotation, Cost of Production, seeding date and weather indicators for disease all need to be considered. Within agronomic decisions there can be tools to estimate the economic impacts of different decisions. The ‘My Farm’, ‘Cost of Production’, ‘Canola Reseed Calculator’ and ‘Sclerotinia Treatment Decision Tool’ are all based on yield trends and agronomy to help make economic decisions easier.

See slideshow at http://www.gov.mb.ca/agriculture/business-and-economics/financial-management/pubs/presentation-mac-agronomicseconomics.pdf

Submitted by Roy Arnott – Farm Business Management, Killarney and Anastasia Kubinec – Crops Branch, Carman.

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If I plan to sow Fusarium-infected seed, when should I use a seed treatment?

Using good quality seed, with high germinability and vigour, and low disease incidence, is always recommended. Cleaning of grain to remove fusarium damaged kernels can improve grade and seed germination. In addition, seed should be planted into warm, well-drained, fertile soil at the appropriate depth. Applying fungicidal seed treatments to cereal seed is also a beneficial management practice that helps reduce risks associated with seedling mortality and reductions in stand establishment due to seed-borne, seed-transmitted and soil-borne fungal pathogens especially when planting conditions are not optimal. Fusarium species are examples of fungi that can cause disease on germinating seeds and seedlings and reduce plant populations. The level of Fusarium infection in a seed lot should be determined by laboratory testing, not just by counting fusarium damaged kernels. In cases where Fusarium infections reduce germination, a germination test should be used to adjust the seeding rate so that emergence and yield are not compromised. Research has shown that when seeding rates are adjusted based on germination rates, seed with low levels of infection (5-10%) have no significant improvement in emergence or yield due to a seed treatment (May et al., 2010). However, it is important to keep in mind that other soil-borne, residue-borne or seed-borne microorganisms (i.e. pests other than Fusarium spp.) can also cause diseases on germinating seeds and seedlings, so even if Fusarium is not detected on seed, a seed treatment should still be considered as a beneficial risk management tool to protect against additional threats such as Pythium spp., Rhizoctonia spp., and others.

Seed treatment recommendations for each province are as follows:

Alberta

Threshold – 0%

Actions/Recommendations – Always use healthy seed with no detectable levels of F. graminearum

Always use a registered fungicidal seed treatment that includes Fusarium on the label

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex5210

Saskatchewan

Threshold – 2-3%

Actions/Recommendations – Use a seed treatment for F. graminearum infection in areas where F. graminearum is not established

Threshold – 5%

Actions/Recommendations -Do not use seed when F. graminearum infection levels exceed this threshold in areas where F. graminearum is not established

Threshold – 10%

Actions/Recommendations -Use a seed treatment when total Fusarium spp. infection levels exceed this threshold in areas where F. graminearum is established or when F. graminearum levels are less than 5% in areas where F. graminearum is not established

https://www.saskatchewan.ca/business/agriculture-natural-resources-and-industry/agribusiness-farmers-and-ranchers/crops-and-irrigation/crop-protection/disease/fusarium-head-blight

Manitoba

Threshold – none

Actions/Recommendations – Use clean seed with good germination, seed treatments may improve germination

http://www.gov.mb.ca/agriculture/crops/plant-diseases/print,dealing-with-fusarium-head-blight.html#field

REFERENCES

May, W. E., Fernandez, M. R. and Lafond, G. P. 2010. Effect of fungicidal seed treatments on the emergence, development, and grain yield of Fusarium graminearum-infected wheat and barley seed under field conditions. Can. J. Plant Sci. 90: 89 3_904.

Submitted by

Holly Derksen, Field Crop Pathologist

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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If I have grain or seed infected with Fusarium graminearum can I plant it?

In Alberta, any grain with detectable levels of F. graminearum cannot be used for seed because F. graminearum is a declared pest under Alberta’s Agricultural Pests Act. Section 22c of the Agricultural Pests Act states: “No person shall for propagation purposes acquire, sell, distribute or use any seed, root, tuber or other vegetable material containing a pest.”

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex5210

In Saskatchewan, F. graminearum is not a regulated pest. However, to reduce the spread of F. graminearum into areas where it is currently not established, seed containing more than 5% F. graminearum is not recommended to be used.

https://www.saskatchewan.ca/business/agriculture-natural-resources-and-industry/agribusiness-farmers-and-ranchers/crops-and-irrigation/crop-protection/disease/fusarium-head-blight

 In Manitoba, there are no restrictions or thresholds for planting F. graminearum-infected seed. However, grain should be tested for germination and Fusarium infection before determining its suitability for seed.

http://www.gov.mb.ca/agriculture/crops/plant-diseases/print,dealing-with-fusarium-head-blight.html#field

Submitted by

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture and Forestry

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Will storage of infected grain for over 1 year reduce Fusarium spp. infection and DON levels?

The viability of various Fusarium spp. during storage is dependent on the storage conditions, with temperature playing a key role. Scientific studies have demonstrated that Fusarium infection levels will be reduced when infected grain is stored for at least 6-9 months at a constant temperature of 25 °C and where either relative humidity is >62% or seed moisture content is at least 10-14%. One study demonstrated elimination of Fusarium graminearum when corn seed was stored in sealed containers at 30°C and a seed moisture content of 14%. However, the same is not true for infected grain stored at cooler temperatures (less than 15°C) which are more consistent with the recommendations for grain storage on the Canadian Prairies. At temperatures below 15C the viability of the pathogen (Fusarium spp.) is unchanged, unchanged, especially under drier conditions, making long term storage of infected grain a poor strategy for reducing Fusarium infection levels. Also, if the grain is to be used for seed, prolonged storage of infected grain at higher temperatures and moisture levels may result in reduced vigour and germination rates.

The mycotoxin deoxynivalenol (DON) in Fusarium infected grain is also unaffected by long-term storage, regardless of the temperature. Under safe storage conditions changes in DON levels would be unlikely.

Submitted by

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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If my grain has high levels of DON can I still use it for seed?

Deoxynivalenol (DON) is a mycotoxin produced by the fungus that causes fusarium head blight (FHB). The importance of determining DON levels in your harvested grain relates to the use of that product for human/animal consumption. DON is poisonous to humans so it is carefully monitored in grain used for food. Additionally, it is poisonous to livestock and can cause feed refusal and poor weight gain in livestock if present above recommended levels.

The relationships between fusarium-damaged kernels (FDK), seed infection by Fusarium spp., and DON levels are not consistent. Just because FHB was observed in the field and/or FDK were observed in a harvested sample it does not necessarily mean that DON is present. Conversely, the lack of these symptoms does not necessarily mean that DON is not present. The latter situation is often the case in years where conditions are conducive for Fusarium infection after anthesis. These DON levels are not accounted for when grading grain is based solely on the percentage of FDK.

While DON levels may affect the suitability of harvested grain as food or feed, seedling health and seed germination is affected by the extent of infection of seed by hyphae of Fusarium graminearum.  Thus, the level of infection by Fusarium spp., including F. graminearum, is a better measure of whether or not the grain should be used for seed in a subsequent season.

Recommendations:

For purposes of replanting, growers should have seed tested by an accredited lab for germination, vigour, and Fusarium infection levels. Based on this information growers can determine whether or not a grain sample is appropriate for planting (with or without a seed treatment) and whether the seeding rate would need to be adjusted. (See future questions in this series that will address whether or not to plant Fusarium-infected seed.)

For purposes of marketing and livestock feeding, growers should have grain tested for DON levels by an accredited lab. Grain companies and buyers are increasingly requesting information on DON levels as opposed to just FDK.

Submitted by:

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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Is Manitoba’s Winter Wheat Crop Set Up to Survive Winter?

The most common question I receive over the winter months related to winter wheat production is “How is the cold weather/warm weather/lack of snow impacting my winter wheat?” Unfortunately, there are no easy answers over the winter months as we typically have to wait until spring when winter wheat breaks dormancy and stand establishment is known.

However, there can be a few key factors during fall establishment and weather conditions over the winter months that can provide guidance in terms of assessing weather and its impact to Manitoba’s winter wheat prior to the crop actively resuming growth next spring.

First step: record crop condition prior to winter. The crop stage and health/vigour of the crop as it heads into winter will provide an indication if the crop has a high chance of surviving the winter with minimal winterkill or winter injury. Ideally plants should be at the 3 leaf to 1 tiller stage and have well-developed crown tissue (and of course established into adequate standing stubble to ensure snow catch). And remember, the stage of crop development in the fall influences not only winter survival, but also yield potential, crop competitiveness, maturity and the risk of infection with diseases such as rust and fusarium head blight.

Second step: note the weather after seeding and prior to winter. Cool conditions in the fall where plants grow for 4 to 5 weeks, followed by 4 to 8 weeks (October to November) of growth that allow plant to acclimate and vernalize, is the ideal situation (relates back to an optimum seeding date of the first couple weeks of September). Read more about cold acclimation and vernalization here: http://cropchatter.com/winter-wheat-survival-impacted-by-fall-management-decisions-the-weather/. Another key weather factor is open field conditions with little or no snow cover until freeze-up as this allows soil temperatures to gradually decline to freezing levels.

If your winter wheat crop and the fall weather met the above conditions, your crop is likely well-positioned to survive Manitoba’s winter.

Third step: record any weather stresses over the winter months. In the fall, winter wheat producers can take all the necessary steps to set their crop up to survive winter with minimal winterkill or injury. However, it is often the winter/early spring weather in Manitoba that can impact winter survival.  Producers should take notes of cold snaps (how long they lasted, when did they occur) and the snow cover during those events to gauge potential impact to their winter wheat crop.

Regardless of the amount of cold acclimation, we typically need to receive good snow cover to protect the crop from the sustained cold temperatures normally seen in January and February in Manitoba. The ideal situation would be a minimum of 4 inches of trapped snow cover through December to early March to buffer soil temperature changes and provide protection to the crown tissue.

To assist with recording any soil temperature stresses, there is real-time monitoring of soil temperatures in the four winter wheat fields across Manitoba (see http://cropchatter.com/monitoring-real-time-soil-temperatures-in-manitoba-winter-wheat-fields/). The data will also be made available in the near future to the Winter Cereal Survival Model website at https://www.wheatworkers.ca/wcsm.php which can provide additional information on potential injury due to cold soil temperatures.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

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