12 min read

The Cropwalker - Volume 4 Issue 36

Always read and follow label directions.

To become a member and receive all issues, sign up at: https://www.getrevue.co/profile/Cropwalker/members

After becoming a member, you can view past members only issues at newsletter.fieldwalker.ca, plus any future issues will be emailed directly to your inbox. Issues with a blue star indicate that they are member's only, just enter your email address on the issue, and it will be sent to your inbox.

Spam Filters

Please ensure  the Cropwalker newsletter is added to your safe sender list or add cropwalker@getrevue.co to your email contacts. There are a few email providers blocking the newsletter. If you missed getting a past issue, you can send it yourself at newsletter.fieldwalker.ca.

Crop Conditions

Weather – we have had a lot of wind, hail, rain and just nasty weather. But through it all crops are doing amazingly well, except for fields or parts of fields that are severely damaged. Corn harvest has started. Early yields are in at 180-200 bu/ac. This bodes well as later fields should yield better. Moisture is in the low 20’s, test weight is fine and early vomitoxin test are low. Corn silage harvest has been ongoing for about 2 weeks. Yields are good. Moisture is dropping quickly. For grain corn expect moisture to drop about 0.5 points per day, give or take a bit. Factors involved include heat, sunlight, wind, and husk tightness. The biggest issue is Tar Spot. There are numerous other diseases in corn fields, including anthracnose, grey leaf spot, northern corn leaf blight, and rust, as well as other minor diseases. This is a good time to check your fields and see what disease you have. There is significant concern about stalk quality. Corn is black layering ahead of normal based on CHUs. A lot of fields of top die back which is a combination of stalk diseases and corn plants drive to fill the ear. The nutrients normally come from the stalk and lower leaves, but if those sources do not supply enough nutrients to fill the ear it will start drawing from the top of the plant. In spite of all the problems in the corn fields we are looking at a record yield. Soybean harvest has started. Moistures are at moisture of commerce. One reader in Clinton area has about 200 acres off averaging about 70 bu/ac. Moisture was 12-15%. If you harvest below moisture of commerce, you lose yield. You lose approximately 1% yield for every point below moisture of commerce. If you harvest say 2 points below moisture of commerce you lose 2% yield. So, if you are averaging 50 bu/ac you would lose 1 bu/ac. There is incentive to start combining above moisture of commerce to minimize the number of acres that will be below moisture of commerce. Winter wheat planting has started. Due to early harvest of edibles and soybeans. Edible bean yields have been very good.  Forages what a year. Best provincial yields maybe ever. If you can store some for next year suggest you do it. We could have dry weather next year. We have passed the last day for seeding grasses. If you have a thin alfalfa field, you want to take a first cut next year you could no till cereal rye into it. This is a good fall to fertilize forage fields. I would rather do it now than count on field conditions being ok next spring. You will have to spread sulphur (S) next spring but you can use a low product rate to get enough S on.


Things to do this week

1.     If you make corn silage, make sure all family members, and hired help are aware of the dangers of silo gas.

2.     Check you corn fields for prevalent diseases. Do a stalk push test to check for standability.

3.     If planting winter wheat check planting depth across full width of drill.

4.     If you have any old corn rootworm insecticide boxes, get them out, clean them up and advertise for sale. We will need them for corn-on-corn growers

5.     Safety thought. Keep 3 points of contact when climbing any ladders even into tractor.

Tar spot Has been in Ontario since 2020. This year it was first noticed in early July. Since then, it has been detected in all counties west of 400. I imagine it will be across Ontario certainly by next year if not this year. Weather is a big factor. The fungicides are fairly effective in controlling it. You get 14-21 days protection from a fungicide. We wrote in an earlier issue that some fungicides give longer protection. There does appear to be differences among hybrids. The Ontario Corn Committee is considering rating hybrids in their trial for tolerance to Tar Spot. In the meantime, check any plots in your area. A strategy for next year is pick the most tolerant hybrid and then be ready to spray. Since the disease spreads quickly you should be able to count on OMFRA’s alert to know when to spray. If the disease comes as early as this year you may have to spray twice. I am not as concerned about Tar Spot as I am about fusarium. Here are some links to read more about tar spot.



Crop Protection Network at www.cropprotectionnetwork.org/

Corn IPM Pipe – tar spot tracking and reporting at https://corn.ipmpipe.org/tarspot/

My buddy Darel who is a CCA in Indiana has commented in his crop report that virtually every corn field in his area has died mainly due to Tar Spot but also has anthracnose northern corn leaf blight and physoderma (a new diseases that is just starting to show in Ontario) He is expecting a good 15 bu/ac advantage by spraying a fungicide at silking. He has one field that received two fungicide application. It looks quite green.

Comment from growers over the years “If these soybeans ever get back to 16%, I am taking them off.” So why not start by taking soybeans at 16% now and gain the many benefits of an early harvest. By starting at 16% you may avoid harvesting soybeans that are too dry. The table below shows the penalty of delivering soybeans below moisture of commerce.

Figure 1 - $ Lost per Bushel on Overly Dry Soybeans at Various Prices

Glyphosate on Alfalfa/Forages Pre-Harvest

Q What can I spray to burndown alfalfa pre-harvest and how long do I have to wait until cutting it?

Ans You can spray up to 2 RELs of glyphosate (1.33 L/ac Roundup Transorb/Weathermax) pre-harvest. This is the ONLY product you can use and feed to livestock. Cutting interval suggests 3-7 days. 3 days is likely adequate when you have excellent growing conditions for translocation. Right now, 3 days is probably all you need. I would use 7 days for less-than-ideal growing conditions (such as when it looks like alfalfa was stuck in a fridge).

If you are using a non-Roundup brand glyphosate, read the label.

I want to terminate an Alfalfa stand, when should I cut or do tillage?

If you have quack grass or thistles (anything with rhizomes), and/or are not ploughing, glyphosate required.

  1. Planning on cutting at this time of year? Spray pre-harvest
  2. Not cutting? Spray with a minimum of 100-150 GDD left in the season for translocation to ensure a good kill. Sooner than later is likely a good idea.

If you have no perennial weeds, and are ploughing, no glyphosate required.

What can I add to my liquid wheat starter and be crop safe?

According to the South Dakota State University salt index calculator, you can add one of the following across all soil types and be crop safe if applying starter in-furrow. Note the crop safety of ATS, for adding 3 to 6 lbs. of S per acre in the fall, it is NOT worth the risk of trying to blend a bit in. This was confirmed with past conversations I have had with The Anderson Group.

Figure 2 - Safe Liquid Starter Rates for Wheat

Cold Sensitive and Cold Tolerant Weeds – Purdue researchers suggest that weeds are either cold sensitive or cold tolerant. Cold sensitive weeds do not readily take up herbicides after a light frost. Weeds in this group include dogbane (looks a bit like milkweed), milkweed and bindweed. Spray these before a frost. Cold tolerant weeds take up more herbicide after a good frost. The frost triggers the plant to store more nutrients. Thus, herbicides are translocated more/better than before a frost. Weeds in this group include dandelion, wild carrot, and quack grass. Spray these weeds three to four days after a heavy frost. Consensus is that perennial sow thistle is neither cold sensitive, nor cold tolerant. From my experience perennial sow thistle can be controlled any time now if you have actively growing rosettes. All of this must be practical. You cannot wait forever to get all the spraying done. If you spray and work the ground generally kill is improved.

Note from Paul Sullivan, CCA in eastern Ontario commenting on scouting with SWAT maps.

Morning folks-

To get to the true cause of corn growth, one must look to the root. Get to the rooooot (American twang) of the problem!

We walked the corn at the Ottawa Smart Farm on Friday. Quite variable soils from sand to strong silt loam. The corn had a tough start kind of jammed in. Was strip tilled (actually Fertile strip tilled as done by GPS Ontario).

The sands are shut down SWAT Zones 1 particularly. Forced black layer. The sweet soils SWAT 4 to 6 very solid 16 round by 35 long at a cob population of about 30-31. The picture below is from SWAT 10 zone where the roots have been locked up by a soil density layer that was in this part of the field previous management and not removed before going into a vertical tillage program.

It didn’t affect the corn until we got dry in August. That is what the cobs are telling us and the 5 to 8 end kernels that pollinated have flexed back reducing yield by 20 to 40 Bu/acre.

Its sure cool to be able to go through a field this time of year with the SWAT Record app and find this productivity potential zone’s and read to plant. It tells us a lot.

Have a good Monday all. Paul

Picture 1 - Zone 10 Corn Roots and Cobs

Accuracy vs Precision when it comes precision ag, what’s missing? Execution!

Many readers of this newsletter are likely familiar with the old adage of making a recommendation that is both accurate and precise. Precise being how close you can get to hitting the bull’s eye, with accuracy being how often you hit it. But when this conversation came up, the key piece was what should the size of the bull’s eye be? And can we even hit it if we are trying to be precise. I do feel that this part seems to be missing when it comes to putting together precision ag recommendations and the scripts that come out of the programs.

How do we fix this? First, you need to understand the margins of error with the data you are working with and what would make a difference in the script being applied. Secondly, you need to understand what the equipment is capable of applying. Once all of this is determined, it is still imperative to determine if the cost of doing all of this work is worthwhile.

Adjusting values of fertilizer at low rates over the field may not add much in the way of environmental or agronomic benefit other than increasing costs to the grower. That means that there are four key pieces to this puzzle; Determine how much variation there is, how accurate and precise it can be applied while being economical, and what the equipment can execute.

Figure 3 - Accuracy and Precision vs. Execution

TKW is the Main Factor Affecting Corn Yield Variation

The first factor affecting corn yield variation of the field is the weight of the kernels (thousand kernel weight) on the cob. Ever count cobs and get 18x30 on the knoll but the kernels are tiny, and 18x30 on the best part of the field but the kernels are much larger? Me too. But they didn’t yield the same. The second factor affecting corn yield variation is the number of cobs. The third and fourth factors are the number of rows and the length of the rows. Take this data for what it’s worth, it’s anecdotal observations from walking fields.

Group 14/15s – Use Pattern in Winter Wheat

These products are registered for pre-plant or pre-emerge application and can help when you are battling winter annuals weeds and struggle with timely spring herbicide applications, or when would prefer to delay your spring herbicide application, so that you can make better use of your 1st fungicide pass.

If you have been battling tough grassy weeds such as bluegrass, downy brome, and wild oats, then look to using group 15 products that contain Pyroxasulfone. Examples include Focus, Fierce and Zidua.

If you have been struggling to get ahead of winter annuals such as chickweed, bird’s eye speedwell, and weeds that seem to germinate all the time like dandelions and Canada fleabane consider a group 14.

Eragon LQ (grp 14)– personal and industry experience supports using the high rate for suppression activity on winter annuals, especially those in the brassica family.

Valtera (grp 14) – is an option for those not using Eragon LQ pre or post harvest, and do not have to control emerged glyphosate resistant fleabane. Please read label directions prior to use (must seed at least 1” deep).

Finally, if you’re looking for an option that has both group 14 and 15 in one product, that would be Fierce (pyroxasulfone and flumioxazin), again read the label directions around time of application and seeding depth.

Future of Agriculture Podcast Interview – Jonathan

I was recently interviewed by Tim Hammerich for the Future of Agriculture podcast on the technology I have adopted to help service my customers. Here’s a snip it from the podcast webpage;

In today’s episode, Jonathan and I discuss the evolution of precision agriculture adoption in his area of Ontario. How he is building his agronomy business using SWAT Maps as part of his foundation. His agronomy tech stack, what tool he still would like to see created, and why tech will never fully replace the agronomist. Oh, and why he prefers the term “optimal rate” over the term “variable rate”.

Future of Agriculture: FoA 274: [Tech-Enabled Advisor Series] Precision Ag with Jonathan Zettler of Fieldwalker Agronomy

Future of Agriculture: FoA 274: [Tech-Enabled Advisor Series] Precision Ag with Jonathan Zettler of Fieldwalker Agronomy

Learn more about SWAT Maps:  Fieldwalker Agronomy:   Jonathan on Twitter:   Today’s episode is all about precision agriculture, so if you’re into agronomy and variable rate technology, or what our guest would prefer to call optimal rate technology, you’re in for a real treat. If these terms are new to you, at a basic level we are talking about technology that is being used to understand the variability of a field so that the precise (hence the name precision) amounts of a given seed, fertilizer, or other input can be applied in a way that maximizes the crop response, and of course, overall profitability. Plants don’t grow by the acre, they grow on an individual basis and may respond differently based on site-specific factors. For more on precision ag, find these previous FoA episodes: 256, 244, 243, 218, 211, 200, 196, 179, 175, 108, 25.  Today’s episode is part of a series I’m doing called the Tech-Enabled Advisor. These are episodes I’m releasing once per month with the intention of better understanding agtech through the lense of the buyers and users rather than just the entrepreneurs or investors. We’ve done four of these so far: 255, 259, 264, and 269, and from what I’ve been hearing the reception has been excellent.  Joining me on today’s episode to talk about precision ag is Jonathan Zettler, who is an agronomist and the founder of Fieldwalker Agronomy Limited, a private crop consultancy in Minto, Ontario. After 17 seasons in ag retail, Jonathan launched the company to provide “profitable, actionable advice” to farmer customers.  To make sure we hear from different types of guests on this Tech-Enabled Advisor series, I’ve asked various agtech companies to partner with me on these episodes. For today’s episode, I’m fortunate to be partnering with Croptmistic Technology, the creators of SWAT Maps. Some of you may remember Croptimistic from my interview with company president Cory Willness last year in episode 211, or the separate podcast I do in partnership with them called SWAT Agronomy. Jonathan at FieldWalker was the first provider to test and start offering SWAT Maps in Eastern Canada.   For a brief refresher on SWAT Maps, SWAT stands for soil, water, and topography. These maps are high resolution soil foundation maps used to execute variable rate fertilizer, seed, soil amendment, herbicide, and precision water management. Instead of just using imagery of vegetation, also known as NDVI imagery, SWAT Maps takes an integrated soil-based approach that starts with RTK or LIDAR elevation, soil color sensors, and electrical conductivity. Then they use that data to build more useful layers: topography models, water flow paths, normalized EC layers, and soil organic matter. With a patented process and proprietary software tools, layers are modeled into a single encompassing map that depicts soil properties, water influences, and topography of the field. Croptimistic Technology is the company that created SWAT Maps and they partner with companies like Jonathan’s to implement the technology and combine it with local agronomic advice. Learn more about them at SWATMaps.com.  In today’s episode, Jonathan and I discuss the evolution of precision agriculture adoption in his area of Ontario. How he is building his agronomy business using SWAT Maps as part of his foundation. His agronomy tech stack, what tool he still would like to see created, and why tech will never fully replace the agronomist. Oh, and why he prefers the term “optimal rate” over the term “variable rate”.

“The way I run this thing you’d think I knew something about it.”

– Bugs Bunny