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The Cropwalker - Volume 3 Issue 16

Always read and follow label directions.

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Crop Conditions

Winter wheat continues. Earliest is at first node. Most has some nitrogen on. Exception is heavy soils in Haldimand areas. Growers who split will be putting the second split on in 10 days. Some Septoria showing up. This is Septoria that started last fall. Too cold to get it going yet. Spring grain planting has started across the province with some growers done. Corn planting has started across the province. Some growers in Huron-Perth are well on their way. Lambton Middlesex areas are planting on lighter soils. Some on heavier soils waiting for rain to go through. General comment is that ground is working up nice. This is to be expected since we did not get a lot of pounding rains to destroy soil structure.


Temperatures for Weed Control in Winter Wheat – I do not like to spray if the temperature is going to drop below 5C the night after spraying. Weeds must be actively growing to be killed. With low temperatures they are not growing as actively. Similarly, wheat must be actively growing to break down the herbicide. Sunlight and daytime temperature also enter the equation. On bright sunny, warm days it takes fewer hours to kill weeds and fewer hours for wheat to break down an herbicide. If spraying early in the season when weeds are small you can get as good of kill with lower rates of hormone herbicides than needed once weeds get bigger.

What Temperatures Seriously Affect Winter Wheat? – Wheat that is dormant can withstand very cold temperatures. Once it starts to grow it can be damaged easier than when it is just breaking dormancy. Once wheat starts to joint (stem elongation), it can be injured by temperatures below -7C. At this stage the developing head is above ground. Once it starts to joint, temperatures below -3C can damage wheat. These temperatures need some clarification. If it dips to these temperatures for a short time the damage is less than if it is at these temperatures for hours. Also, if soil is wet these air temperatures will be moderated by heat given off of the soil.

Question: How do I control Bluegrass (Poa) in the Spring in my Forage Stand

Answer:  Unless you have a pure-stand of RR alfalfa, there are no products registered to spray in the spring to control bluegrass in an alfalfa stand, that will be harvested this year for forage. The solution is to live with it or kill off the alfalfa and plant other acres to alfalfa. The real issue is why do you have bluegrass? Blue grass will start to grow in an alfalfa field if the alfalfa dies out. I have seen research on controlling dandelions in established forages. Once they were controlled the dandelions, the yield in the plots was lower than in the check plots. The same will occur if you control bluegrass. The alfalfa will not thicken up. Generally, two reasons for bluegrass growing in an alfalfa stand. 1) The stand is old (more than 3 years) and is thinning out. 2) Alfalfa is on heavy clay and is dying out to root diseases that thrive in heavy soils for various reasons. Generally, the bluegrass is Canada bluegrass, which is native to Canada. A lot of old forage fields have a good supply of un-germinated Canada blue grass seed. The solution on these fields is to make sure the forage stand is well fertilized to crowd out the bluegrass. Alternative solution is to plant Xtend alfalfa. Then when the alfalfa thins out, you can kill off the blue grass and seed another more acceptable grass species. Generally, fields with extra nitrogen such as fields with a history of manure are more prone to bluegrass becoming a weed.

Question How long do I really have to wait between spraying glyphosate and working the ground?

Answer It is really species dependent. Perennials, and biennials will take longer to kill than annuals. Weeds with a bigger root system like Canada thistle, bindweed take longer. Individual species can be very sensitive to glyphosate. Winter wheat is very sensitive to glyphosate. If it is sprayed on a warm day there will probably be enough glyphosate translocated in the first couple of hours to kill winter wheat. The other thing is that the longer you wait the better the kill. So, in the case of perennials you need the full 48 hours or so for maximum kill. But even if you wait a few hours you will get some kill. The objective is to wait as long as possible for best kill. If you feel you will not get planting done before the next rain better to accept less than 100% efficacy and get the seed in the ground. Another factor is weed size. Weeds like big dandelions will not be killed in the spring no matter how long you wait. Experience has also shown that weeds like the lamb’s quarters sort of lookalike spreading Atriplex are hard to kill once they get over 2-3”.

Question Can I spray Eragon for fleabane control before seeding alfalfa peas and oats?

Answer No. The peas and oats are safe but not the new alfalfa seeding. BASF trials showed too many times there is a risk of damage. They are trying to figure out what if anything can be done. Same with Elevore, too much damage. Liberty is not an option since weather is too cool. Options now are 1) mould board plough. Secondary tillage with a cultivator or disc will just move them around. 2) Spray Eragon and Merge and glyphosate now. Plant the peas and oats now, and seed alfalfa in August after peas and oats are harvested.

Rules of Thumb for N on Spring Cereals

An increase in spring grain acres again this year. For best yields you need to plant early, make sure you have enough nitrogen and apply fungicides twice. The further north your location, the higher the N rate you should consider. Consider a credit off of these values for manure and alfalfa.

Figure 1 - Nitrogen Rates on Spring Cereals

Question How do I control red clover in a field going to corn?

Answer; The best way is with dicamba. But you do not want to spray dicamba and then work the ground to plant corn. Better option is to spray glyphosate before you work the ground. This will give some control. After corn and red clover has emerged use dicamba in one of the various ways, e.g. with glyphosate or with atrazine (Marksman), or consider using Lontrel (can be mixed with glyphosate). Do not tank mix glyphosate and Distinct.

Cereal Fungicide 101

Here is a basic understanding of fungicides. If you think of fungicides as herbicides you might understand better. First there are 2 main groups. Alphabetically they are strobilurins (strobis) and triazoles. The first alphabetical group (strobi) think of them as stopping germination. They prevent spores from germinating. The second group think of them as stopping the spores that germinated from growing more. They prevent mycelium growth. (Apologies to all pathologists). Since fungi go through a very fast life cycle it is impossible to stop all the spores from germinating or stop all the germinated spores from growing. And since spore formation is a function of the weather and the disease it is not very possible to say one product is a lot better than another. Many products are good against many diseases, but certain products are BELIEVED to be better against some diseases such as white mould. There are differences as to how fungicides move in the plant and how long they stay active. Sunshine and rain can break them down.  However, the strategy is to not depend on one group or the other. In fact, many of the better fungicide products are a combination of the two groups. The new product Miravis Ace from Syngenta has another group. Miravis Ace has 3 modes of action.

Figure 2 - Fungicide Timing and Yield Response in Winter Wheat

This chart gives a relative importance of fungicide timing. T1 is at growth stage 30-31 - stem elongation or herbicide time. T2 is at flag leaf and T3 is fusarium head blight timing. There are other research trials that show different yield increases. Part of it is the variety used. Some varieties have better resistance to certain diseases. So, depending on the variety and the year you could get different results. Bottom line, you need two fungicide passes to maximum wheat yields.

This week’s Mystery Weed

Just a picture for this week.

Picture 1 - This week's Mystery Weed

Last week’s Mystery Weed – White Cockle

Picture 2 - Last week's Mystery Weed - White Cockle

White Cockle is native to Europe and was first found in Ontario in 1875. It reproduces from seed and can become a deep-rooted biennial or short-lived perennial. A common source of infestation is through contaminated alfalfa or clover seed, as the seed size is similar. It tends to be an issue on hay fields, and cropping practices that promote reduced or no-tillage. When in hay or forage crops, the problem continues to spread due to seed distribution in the baled forage.

White Cockle can be a very heavy seed producer, so it is best to keep this weed in check to prevent it from taking over a field. Cultivation is likely to spread an infestation, due to stem and root pieces sprouting to form new plants. Frequent mowing will reduce seed production. Crop protection wise; 2,4-DB, Barricade M, Mecoprop, Refine SG (in cereals) or Express SG (burndown in cereals/soybeans) are suitable products to take out seedling versions of this plant. While not listed on the label, I would expect glyphosate to have some activity.

For more information visit;

Alberta Extension - White Cockle

White cockle - WeedInfo.ca

Mixing Liquid Micros with Liquid Fertilizer Products

Have had a few questions over the past week or so on what products can mix with various liquid fertilizers. The best summary I have found is the chart below, compiled by Dale Leikam of the Fluid Fertilizer Foundation. Want to use a product with the least amount of issues? Use an EDTA based product micronutrient. Still unsure? Check with the supplier or do a jar test.

Figure 3 - Mixability of Various Liquid Micornutrients

Number of customers using 10-34-0 for the first time, a few pointers on keeping product in condition.

APP Storage and Housekeeping Suggestions – Dale Leikam

·        Do not store longer than necessary

o  Avoid storage in summer months

o  Shelf Life is About 6-12 Months at 75 F or cooler

§ Longer with Cooler Temperatures, Much Shorter With Warmer Temperatures

o  Product Converted to NPK/Micro Grades Shorter Yet

o  Completely empty and clean tanks regularly

o  Know the quality of remaining product before adding additional product to tanks

o  Problems likely below 60% polyphosphate

o  Don’t contaminate Good Product

·       Do not contaminate with products/impurities that may affect storage properties

·       Never, ever contaminate storage, mix plant or lines with any calcium or magnesium

·       Make sure that farmers and dealers’ lines, tanks and equipment are completely cleaned after use

·       Paint Storage Tanks White to Aid in Keeping Product Cooler

How long does it take for phosphorous to convert from Polyphosphate to Orthophosphate?

Figure 4 - Temperature Impact on Conversation from Poly to Ortho Phosphate

Winter Wheat Staging Guide

With great graphics and the use of both methods of cereal staging (Feekes and Zadok’s – Zadok’s the standard in Ontario, Feekes in the US, for field crop recommendations), this is a great guide to keep handy when working with cereals. One item of note is the use of the term “jointing”, which in Ontario is typically called stem elongation.

U of WI - Wheat Growth Stage Guide

Nitrogen Cycle – Relative Size of Additions and Removals

Last week I was asked if we should be changing our N recs with the amount of nitrogen coming from atmospheric fixation. Short answer, No. For perspective, the amount of N mineralized from year to year from soil organic matter will differ more than the total amount provided through atmospheric fixation

Nitrogen Cycle Source: IPNI

Figure 5 - The Nitrogen Cycle

Row cleaners – Proper Setup

Row cleaners are to be used to move crop residue (and stones) aside so that the seeding or planting implement can perform soil engagement. To do this, the row cleaner should gently move the trash aside, without engaging the soil (they are not designed to be a tillage implement). See video below for example.

Row cleaners used in Strip-Till

One of our readers was recently filmed by Ian McDonald – OMAFRA Crops Innovations Specialist, on their use of row cleaners to reduce the tillage requirement prior to planting corn. This will be the next strip for those currently doing strip-till and want to reduce the amount of tillage used in their operation (will need to figure out another method for nutrient placement). See video below for example.

"I don’t think people purposely go down the wrong path. I just think that they’re unaware. Blind spots mean that they’re blind spots. You have no idea. You’re totally surprised when all a sudden you see something that you never saw before. And one of the greatest things we could do for others is to come alongside them and help them with those areas."

- John Maxwell