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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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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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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Waterhemp Now a Manitoba Weed

Can you identify the plants in the two pots below?

waterhemp-and-redroot-pigweed

The plants on the right are redroot pigweed (Amaranthus retroflexus); the plants on the left are waterhemp (Amaranthus tuberculatus).

Unfortunately, the need to distinguish between these closely related weed species has become a reality for Manitoba producers and agronomists since waterhemp was found in the province in the fall of 2016. Suspect plant specimen collected from a soybean field in the RM of Taché was verified as waterhemp by staff with the Agriculture and Agri-Food Canada Collection of Vascular plants in Ottawa.  Waterhemp occurs in neighbouring states and provinces, including Minnesota, North Dakota and Ontario.

Both species thrive in agricultural fields where they compete with crops for nutrients, moisture and light. Waterhemp has no hairs on its stem or leaves, which can be used to distinguish it from redroot pigweed when plants are small.  The lack of hairs give waterhemp leaves a ‘glossy’ look unlike that of the ‘dull’ green leaves of redroot pigweed.  Also, waterhemp leaves are lanceolate in shape (longer than they are wide) compared to the more ovate leaves of redroot pigweed.  Colour is not a reliable identifying characteristic since both species can be green, red or variations of the two colours.

Mature waterhemp plants tend to be more branched than redroot pigweed. And unlike redroot pigweed, which has male and female flowers on the same plant, waterhemp has separate male and female plants.  Waterhemp inflorescence are long, slender and vary in colour compared with the compact, prickly inflorescence of redroot pigweed.  Like most pigweeds, waterhemp is a prolific seed producer with up to a million seeds per plant (under ideal conditions).

Waterhemp populations resistant to group 2, group 9 (glyphosate) and group 2+9 exist throughout the US, including Minnesota and North Dakota, and in Ontario. Seed from one of the plants found in Manitoba have been sent to Ontario for resistance testing.

Information on waterhemp will be added to Manitoba Agriculture’s weeds webpage shortly (http://www.gov.mb.ca/agriculture/crops/weeds/) and will be included at the Weed Seedling Identification Day (hosted by the Manitoba Weed Supervisors Association).  Manitoba Agriculture staff will conduct a waterhemp surveillance program in and around the RM of Taché in 2017.

Additional information on waterhemp is available at: http://www.extension.purdue.edu/extmedia/BP/gwc-13.pdf (excluding herbicide recommendations).

waterhemp-tone-ag-consulting

Photo: Waterhemp in Manitoba, Tone Ag Consulting

Submitted by: Jeanette Gaultier, Provincial Weed Specialist, Manitoba Agriculture

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Updated Cereal/Oilseed/Pulse Maps for Yield, Acreage and Seeding Date Now Available

Manitoba Agriculture’s Crop Industry Branch and MASC has updated and posted yield, acreage and seeding date maps for cereal, oilseed and pulse crops at https://www.masc.mb.ca/masc.nsf/mmpp_index.html

The maps can be found at the link above under the heading “Thematic Crop Maps“‎. Time frame in most cases is 2006 to 2015 (10 year), but 2011 to 2015 is also available for soybean, feed wheat and corn to reflect the acreage changes that occurred in the past 5 years.

Many thanks to Doug Wilcox‎ from MASC for the database, and Les Mitchell and Natalie Azure from the Crop Industry Branch who developed and created the maps for this project.

 

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SEED MANITOBA 2017 NOW AVAILABLE!

picture1SEED MANITOBA 2017, the Variety Selection and Growers Source Guide, is a collaborative effort between Manitoba Agriculture, the Manitoba Seed Growers’ Association and the Manitoba Cooperator.  SEED MANITOBA remains one of the best sources for unbiased variety performance information with yield and quality information collected at various sites across Manitoba.

SEED MANITOBA 2017 will be available:

  • Local seed growers
  • Subscribers of the Manitoba Cooperator
  • Local Manitoba Agriculture Offices

 

A digital edition of SEED MANITOBA 2017 will also be available at www.seedmb.ca

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Summary of Presentations from the International Congress of Entomology, September 25-30, 2016

Submitted & Summarized by: John Gavloski, Entomologist, Manitoba Agriculture

The following link provides highlights from some of the presentations most pertinent to agronomists and farmers in Manitoba. Please contact me for further information on these presentations or meetings. Due to there being concurrent sessions at these meetings, there were many more presentations than what is presented in this summary. These were selected because of their relevance or potential interest to those working in agriculture in Manitoba. I have categorized the presentation reported by commodity group or discipline.

The information presented is a combination of material from oral presentations, poster presentations and provided as abstracts for the various symposiums. Many presentations have multiple authors, however only the presenting author is reported in this summary.

http://www.gov.mb.ca/agriculture/crops/insects/pubs/int-congress-of-entomology-2016-summary.pdf

Visit the Insect Pages of our Manitoba Agriculture website at: http://www.gov.mb.ca/agriculture/crops/insects/index.html

 

 

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Summary of Insects on Crops in Manitoba in 2016

A “Summary of Insects on Crops in Manitoba in 2016” is posted on the Manitoba Agriculture insect page at the link http://www.gov.mb.ca/agriculture/crops/insects/pubs/2016-summary.pdf

This report is based partially on observation by myself and my summer assistant. A large part of this information, however, is based on observations and reports from agronomists, farmers, farm production extension specialists, extension coordinators, and others who contributed information over the season. This information was helpful in providing timely updates on where and when insects were of concern throughout the season, and it is a compilation of this data that makes up this summary. Thank you very much to those who contributed information over the growing season.

Note also that the information in the summary is what has been observed personally or reported, and may not be complete in many instances. Although we encourage the reporting of information on insect populations and control to make our weekly updates as complete and useful as possible, some areas of high insect populations and areas where control took place may not have been reported.

I hope this information is useful in your winter planning and preparations for next year

Submitted by: John Gavloski, Entomologist, Manitoba Agriculture

Visit the Insect Pages of our Manitoba Agriculture website at: http://www.gov.mb.ca/agriculture/crops/insects/index.html

Manitoba Agriculture on Twitter: @MBGovAg
Manitoba Agriculture on YouTube: www.youtube.com/ManitobaAgriculture
Manitoba Agriculture website: www.manitoba.ca/agriculture

 

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Testing Weeds for Herbicide-Resistance

Do you have weeds that survived this year’s herbicide application(s)? Since there are many factors that can contribute to weed escapes, consider:

  • The distribution of escaped weeds. Herbicide-resistant weeds tend to occur in patches as opposed to geometric patterns (e.g. spray miss) or throughout the field (e.g. tolerant weeds).
  • Possibility of reduced herbicide efficacy. 2016 was a challenging year for weed management due to untimely and excessive rainfall. In many cases, weeds escaped because of herbicide application timing with respect to weed growth stage, limited herbicide choices because of crop growth stage (when producers finally could get on their fields) and product rainfastness.
  • Weed species. Annual weed species, like wild oat, green foxtail, cleavers, kochia, hemp-nettle, smartweeds, ragweeds and wild mustard, may be more likely to develop resistance compared with other weed species. Because the development of herbicide-resistance is based on chance, resistant weed patches are typically a single species, as opposed to non-resistant weed escapes, which may affect multiple weed species.

Suspect weed escapes can be confirmed as resistant or susceptible by herbicide-resistance testing. For most weeds, dry, mature seed is required for the analysis.  Although more is better, many labs require at least 100 g of small weed seeds (e.g. cleavers) and 200-250 g of large weed seeds (e.g. wild oat).  Weed seed samples should be submitted by December 31st, 2016 to either:

For suspected glyphosate-resistant kochia, a genetic-based tissue test is also available from the Pest Surveillance Initiative: http://www.mbpestlab.ca/field-testing/. In this case, about 5 to 10 g of green plant tissue (e.g. leaves and stems from plant tips) is needed for the analysis. Samples should be placed on ice and shipped immediately after collection. The advantage of the genetic test (vs. seed analysis) for kochia is the ability to determine resistance in-season.

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Submitted by: Jeanette Gaultier, Provincial Weed Specialist, Manitoba Agriculture

For more information on resistant weeds and weed management, visit the Manitoba Agriculture website: http://www.gov.mb.ca/agriculture/crops/weeds/

 

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Are Herbicides Still Effective After a Fall Frost?

Fall is a great time to control perennials such as Canada thistle, perennial sow thistle and dandelion. As temperatures cool, nutrients move from the leaves down into the roots and if a herbicide can be taken up and translocated with those nutrients, it can equal better control. Glyphosate and/or the group 4s are examples of herbicides that provide effective fall control of perennials.

A frost event though, can kill some weeds or can damage leaf tissue which will reduce herbicide uptake and reduce the level of weed control. Within the next few days after the frost, you need to assess the target weeds in the areas that you want to obtain control – are the weeds still growing?  How much leaf tissue has been damaged?

Light frost: A light frost (0 to -3°C) can actually improve weed control by increasing herbicide translocation to the root.  However, duration of the frost also plays a role.  Check your weeds for frost damage if you plan on a herbicide application after a light frost.  Herbicides can only be taken up and translocated by weeds that are healthy and actively growing.

If you do spray – spray in the afternoon when temperatures are warm and sunny, as this will help with herbicide uptake.   You’re looking for daytime temperatures of ~8 to 10°C for at least 2 hours. Use rates appropriate to the stage and time of year – fall applications of glyphosate are recommended at a higher rate than when controlling weeds pre-harvest.

Hard frost: Depending on the damage, a hard frost (≤ -5°C) can put an end to (effective) post-harvest weed control. However, if the plant leaves are still shiny green with minimal leaf tissue damage (i.e. not blackened/brown or brittle) or if less than 40% of the plant has more serious leaf tissue damage (i.e. blackened/brown or brittle) there may still be a window to make a herbicide application. Wait at least 48 hours before assessing frost damage after a hard frost.

If you do spray – read the ‘If you spray’ paragraph above, it still applies.  You need those daytime temperatures to hit ~8 to 10°C for at least 2 hours. In addition, consider your coverage – higher water volumes may improve uptake in more heavily damaged weeds.

One last thing – look at the forecast for the next week following the application.  If daytime temperatures are below 8°C and/or if night-time temperatures are forecasted to continually be below freezing, it may be too late to make the application to get the economic control you are looking for.

Submitted by: Jeanette Gaultier, Provincial Weed Specialist, Manitoba Agriculture

Visit Manitoba Agriculture Crops webpage for more current topics: www.gov.mb.ca/agriculture/crops/seasonal-reports/current-crop-topics.html#agronomy; or the Manitoba Agriculture Weeds webpage for more information on fall control of dandelion and quackgrass: www.gov.mb.ca/agriculture/crops/weeds/.

 

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