Options for Managing Drowned Out Spots

The following is from an article by Tom Peters, Extension Sugarbeet Agronomist with NDSU & U of MN, published in  North Dakota State University CROP & PEST REPORT July 10, 2014 Issue, with a Manitoba perspective by Pam de Rocquigny, Manitoba Agriculture Provincial Cereal Crops Specialist

If you take a drive across Manitoba, you’ll notice the impact of excessive moisture on crops.  Symptoms of excess moisture can include crop yellowing, hastened crop development such as premature bolting in canola, stunted growth, and in extreme cases crop death in drowned out areas.

What options do producers have to manage these drowned out spots?  Producers should continue to actively manage these areas of fields since they are a perfect environment for weeds to grow without crop competition and potentially will produce tremendous numbers of weed seeds. Left unattended, these spots could dramatically impact weed management strategies for future crops in future years.

So what options does a producer have? Some questions to consider are whether you can reach these spots with equipment such as a rotary mower or a sprayer and what will effectively control the weeds?

  • Mowing is a good option, but in all likelihood, affected areas in fields will need to be mowed on 10 to 14 day intervals to prevent weed seed production.
  • Spray the drowned-out areas of the fields as if you were managing a crop if you are still spraying the field for weeds (if the drowned out spots have dried enough for a sprayer pass of course). If you are spraying only the affected areas, be sure to consider the crop around the drowned out spots to prevent damage to the surviving crop.  And keep in mind any potential crop rotation restrictions to next year’s cropping plans with the product you are using.
  • A third possibility is to plant the drowned-out areas of the field to a cover crop such as a cereal, once again if the area is dry enough to allow a seeder to pass. Cover crops will use excess water in soils and will compete with weeds for light and thus may limit germination and emergence of weeds.
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What is Purslane Speedwell and How Do I Control It?

The following picture was received last week for identification. 

 photo

If you have seen this weed and not sure what it is, it is  purslane speedwell (Veronica peregrina L.).  It is a member of Figwort family (another weed from this family is yellow toadflax).

Purslane speedwell characteristics:

  • annual weed 
  • reproduces only by seed
  • Stems are erect and much branched at the base
  • stems have fleshy texture and fine sticky hairs
  • leaves also have fleshy texture
  • flowers are small 4 lobed and whitish in color
  • the plant flowers from mid-May to July 

 

Purslane speedwell has been found at some locations in Manitoba and more commonly in winter cereals. It is also found in gardens, lawns, roadsides and other non-agricultural areas.

 

Unfortunately there is not much information available to control this weed. The USDA Weed Control Compendium mentions poor control from the commonly used group 4 herbicides like 2,4-D, MCPA, Dicamba, etc. No information regarding the efficacy of glyphosate on this weed. The other tough to control weeds in the Figwort family include Dalmatian and yellow toadflax and common mullein.

 

Submitted by Nasir Shaikh, MAFRD Weed Specialist

Want to submit a picture – submit to [email protected]

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Warm Soil Means Fast Emergence….So Go Scout!

With most soil temperatures across Manitoba averaging over 10C, and the good soil moisture, crops planted are emerging quickly!

So, great news, but what this means is it is time to get out and start scouting!

Things to look for are:

  1. Emergence, plant stands, patterns in field – this can indicate if seeds planted evenly, but can also you could indicate early issues like cutworms, soil-borne disease and herbicide residue injury.
  2. Weeds species, numbers and size – if you crop is coming up this fast, so are the weeds!  Targetting the weeds when they are small and knowing the species so you can choose the right product and the right will really help with the control.  Make sure those little yield-robbbers don’t get to use the sun, moisture and fertilizer instead of your crop.
  3. Insects – cutworms were mentioned before, but more look more specifically for the damage on the plants if you can’t see the insect, as that can help with identification.  Are leaves clipped off leaves at or above the soil vs. chewed with ‘shot-gun’ hole marks in leaves.  Keep in mind the economic thresholds for control!
  4. Other funny stuff ?  Keep these in mind too when out scouting and mark down spots (or GPS tag) to monitor as the days go on to see how they progress, sometimes it takes a couple of days before things become obvious.  When in doubt give the Crops Knowledge Centre a call at 204-745-5663.

Submitted by: Anastasia Kubinec, Oilseed Crop Specialist, MAFRD Crops Knowledge Centre.

Resources:

MAFRD Guide to Crop Protection: http://www.gov.mb.ca/agriculture/crops/guides-and-publications/index.html#gfcp

Weed Identification: http://www.gov.mb.ca/agriculture/crops/weeds/

Insect Identification: http://www.gov.mb.ca/agriculture/crops/insects/index.html

 

 

 

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Late Seeded Canola – Yields are Still There, But Control Your Weeds!

Even though we are in the 4th week of May, there is still opportunity and good yield potential for seeding canola. MASC crop insurance deadline in June 15, except for Risk Area 16 which is June 10, so the final deadlines are still two weeks or more away.

Yes, our seeding date is later than what we would like, but remember seeding date is only one component of yield. After getting the seed into the ground or planning of getting the seed into the ground,  weed control is key to a giving canola an early advantage.  Canola is very vulnerable to the weed competition (meaning yield losses) before it reaches the rosette stage. Scouting is important and should start now to get the jump on those yield-robbing weeds!

If you haven’t seeded yet –  a pre-seed burn-down, if time allows, is a great way to get weeds under control before the crop emerges. Seeding can resume soon after – for annuals and winter annuals, glyphosate needs only 24 hours to get to the growing point. For perennial weeds, 3 days should be enough in sunny and warm conditions but 5 days is recommended if weather is cloudy or cool.

If you are fortunate enough to already have your canola seeded – go look for those emerging weeds, noting the weed species, numbers and staging. Then spray as soon as recommended for you canola type, usually targeting the 2 true leaf stage, as weeds will also be small and easier to kill than when they are 4-leaf stage or later and you remove that competition from stealing the water, light and of course fertilizer you put in the ground to feed your crop!

 Insects and disease can also impact yields, but those may be dependent on the weather throughout the spring/summer, weeds though seem to be a consistent concern in most fields and need to be controlled. Good Luck with finishing seeding.

 

MAFRD Guide to Field Crop Protection: http://gov.mb.ca/agriculture/crops/weeds/guide-to-crop-protection.html

MAFRD Weed Identification: http://www.gov.mb.ca/agriculture/crops/weeds/

 

Submittted by: Anastasia Kubinec, Oilseed Crop Specialist, MAFRD

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Glyphosate Resistant (GR) Kochia Confirmed in Manitoba

Manitoba Agriculture, Food and Rural Development (MAFRD) jointly conducted a kochia survey across Manitoba in the fall of 2013 in with Agriculture and Agri-Food Canada (Saskatoon Research Centre) and the University of Manitoba, funded by the Western Grains Research Foundation and BASF Canada.
 
Plants from 283 different kochia populations were harvested, thrashed and planted over the winter. The resulting seedlings were tested for glyphosate resistance.  Kochia plants from two of the 283 sites were found to be glyphosate resistant (GR).  Both sites were in the Red River Valley.  Finding GR kochia was not unexpected as previous surveys in Alberta and Saskatchewan, North Dakota, South Dakota and Minnesota, have all identified GR kochia.
 
Herbicide resistant weeds are not a new issue in Manitoba, as Group 2 resistant kochia and Group 3 resistant green foxtail populations were identified in 1988.  However, resistance to glyphosate is new and it remains an important herbicide in Manitoba crop production systems.
 
If GR kochia populations become more common in the province, it will result in added management skills and expense for Manitoba farmers.  In-crop control of GR kochia can be difficult in broadleaf crops like canola, soybean or pulses and pre-seed or pre-emergent treatments may be necessary for adequate control.
 
As GR kochia has been found in less than one per cent of the sites sampled, Manitoba farmers have an opportunity to minimize the spread of this weed. Farmers should consider reducing the number of glyphosate applications in a single season and incorporate non-glyphosate herbicides in weed management programs when growing glyphosate-tolerant crops.  Farmers will also need to incorporate non-herbicidal measures like crop rotation, tillage and manual weeding if necessary to control populations.
 
Moving forward, MAFRD staff will continue to monitor the two sites where GR kochia was found and work with the affected and neighbouring producers this spring to discuss possible containment procedures. The department will also develop an extension program on herbicide-tolerant weeds, using GR kochia as an example.  The program will be aimed at industry agronomists, grower associations and producers and is expected to be ready later this spring.
 
For more information about GR kochia and related agronomic advice, please contact Nasir Shaikh, provincial weed specialist, at 204 750-2715 or Nasir Shaikh.
 

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