6 min read

The Cropwalker - Volume 1 Issue 6

Always read and follow label directions.

Do You Have Questions?

As part of the price of your membership, Jonathan and Patrick are available by email or phone to answer questions.

Patrick – Cell: 519-275-1058 - Email: patricklynch872@gmail.com

Jonathan – Cell: 519-323-7505 - Email: jz@fieldwalker.ca


How do They Test Corn for DON?

DON is a toxin produced by the fungi fusarium. There are a number of other toxins affecting this year’s corn. Notably zearalenone. It is produced by Fusarium gramineaum and Fusarium culmorum, but also by some Gibberella species. Elevators are not testing for this. When your corn is tested, a small sub sample, is taken from the sample that is drawn for moisture and bushel weight. This sample is ground in a grinder similar to that used for coffee and tested with chemicals for the presence of DON. This is done by inserting a test strip into the ground corn with the added chemical. While this test has inaccuracies due to how the sample is taken, it is the best there is and most people are using the same or similar system.

Handling Cover Crops Now

If your cover crop was seeded into, or after winter wheat, consider terminating it now. If you had a strong cover crop probably little advantage to using an herbicide. It is amazing how well cover crops out compete and smother weeds. Exception is perennial weeds such as perennial sow thistle and dandelion. Consider spaying these if you are doing shallow conservation tillage. If you are mouldboard ploughing, no reason to spray for weed control. I like using conservation tillage rather than a mould board plough to handle cover crops. About 3 years ago we had a conservation tillage demonstration at Canada’s Outdoor Farm Show. All of the 12+ pieces of equipment did a good job controlling the cover crops. Some left more residue on top than others. If you have considerable volunteer winter wheat and the tillage in the past has not terminated it, you will want to burn it off with glyphosate. Either in the fall or in the spring prior to tillage.

One of 20 pieces of equipment in Cover Crop Tillage Demo at COFS

Can I Plant a Cover Crop after Late Harvested Soybeans or Corn?

The best choice is cereal rye. It will give some growth this year, but more next spring before you get on the land. There is a reduced benefit to planting a cover crop after soybeans if the field is intended for corn, as you will need to kill the cover crop early before there is much growth. If the field is intended for soybeans, whether coming out of corn or soybeans, take a long look at seeding cereal rye now.

Making Ruts at Harvest

Not much you can do. You have to get the crop off. Wet harvest rules apply: 1) Try to use the same track as often as possible going down a field. The first track does the most compaction. (Probably 80-85% of the damage is done in the first pass.) 2) Do not drive diagonally across a field. Drive same direction as tillage will occur. 3) Grain buggies may do more compaction than combines (Don’t use grain bin extensions). Grain carts should track the same rows as the combine. When possible make more trips to reduce weight in buggies and combine. (Going to be hard with big yields) 4) You can reduce some compaction with lower tire pressure. Check yours. 5) Don’t turn around in the middle of the field. 6) Best way to get rid of ruts is with a mould board plough. If you have kept ruts to certain areas of the field you may not have to mould board plough everything. Plough the ruts out and then vertical till the rest of the field. 7) Use cover crops to build soil structure.

Principles of Mouldboard Ploughing

When mouldboard ploughing just presume you are going too deep. Most ploughs cannot plough shallow enough. So, try and plough as shallow as possible. Using stalk choppers, either on the header or as a separate pass, allows you to plough shallower. If you are bringing up subsoil, you are ploughing too deep. If there is one thing I learned in 4-H ploughing, it is to get your plough level. Not just level front to back, but also side to side. A properly set up plough follows, one that hasn’t been fights the tractor the whole way down the field.

DON in Corn Silage (Following is a quick summary of a lot of research- read slowly)

DON and other toxins may be more important in silage corn than grain corn. Some interesting research from Univ. of Wisconsin. 1) In those studies, yield was often not directly impacted by the fungicide application, but fibrous changes in the corn plant improved feed conversion to milk production in cows fed silage corn treated with fungicide. 2) DON can accumulate in ears AND stalks. 3) Some hybrids might be more susceptible to stalk DON accumulation than ear DON accumulation (PO956AMX vs. F2F627). 4) DON accumulation in stalks might be independent from ear DON accumulation. 5) Fungicide may not always reduce DON, especially in years conducive for F. graminearum or when stalk infection is a primary means of DON accumulation in the corn plant 6) It might be hard to get fungicide into stalks to reduce stalk infection; Thus, DON still accumulates in the stalk portion, independent of ear infection control by fungicide applied at R1.

Chart shows a reduction in DON but some hybrids have more DON than others

Cover Crop Benefits – Weed Control

This will start to feel like the movie Groundhog Day, but, I keep seeing too many examples to not share them! For this article, let’s forget about the soil health aspects of cover crops. Weed control has to be a significant benefit of using a cover crop in the rotation. It will reduce the amount of herbicides you needed over the crop rotation. The caveat? Use a chaff spreader on the combine. See the picture below to understand what I’m suggesting.

Uneven chaff spreading leads to uneven cover crop weed suppression

Building Prescriptions - Continued (4)

Yield = Sunlight + Heat + Nutrients + Plant Available Water

This is one part of the yield equation I have yet to have a good handle on. One item of note is the impact of frost, both at emergence and maturity. Typically the same part of the field can have both issues. If you plant late enough, the risk of frost is pretty minimal from an emergence stand point. For early planting, pick a hybrid with good vigour for those areas. As for maturity, well, in some situations it could mean managing it through populations due to yield potential or planting an earlier maturity hybrid/variety if the equipment allows it. Another option is to pick a quick drying hybrid with a stong test weight.

Corn Crop Removal Phosphorus and Potassium

I’m hearing crazy high levels of corn yields for 2018. Many of these have been verified through weigh wagons or elevators slips. It’s not just coffee shop talk. Where does that leave your soil fertility “bank”? Likely needing a boost?!? I’ve included up to 300 bu/ac, because, well I’ve seen plot results at that level. Both of us writers agree that at these levels, you should seriously consider putting on replacement P&K with variable rate prescriptions. a) Fertilizer prices are no longer at historical lows, and b) the cost to write the prescription off of yield data is relatively inexpensive to the amount of fertilizer applied.

P&K Fertility Removed at Various Yields in Corn

Phomophsis Seed Decay, Pod and Stem Blight

In the province of Quebec, pod and stem blight can cause up to a 40% yield loss. In speaking with those involved with screening new soybean genetics it is a problem in Ontario for 2018. So what are the symptoms and how do you manage for 2019?

Notes from UWEX Publication A3879 – Common Soybean Diseases

Symptoms: visible on mature, wounded or dead tissue as small, raised black specks, usually in linear rows. Seeds may be white to gray or brown, shriveled and/or have cracks in the seed coat (do not save this seed)

Risk Factors: overwinters in soybean residue, favored by prolonged periods of rain, high relative humidity (100%) and temperatures less than 20 degrees C during pod development and fill.

Management: harvest mature plants promptly, tillage, fungicide seed treatment, foliar fungicide from mid flower to beginning maturity (R6 is ideal). Plant non-infected, disease-free seed.

If you are in an area prone to this disease complex, consider variety selection as a decision factor as well. There are differences between soybean varieties, with some suppliers screening for it and listing it in their guides.

For more information, see the factsheet at the link below from the Crop Protection Network; https://cropprotectionnetwork.org/download/2560/

Failure is not a single, cataclysmic event. You don’t fail overnight. Instead, failure is a few errors in judgment, repeated every day.

- Jim Rohn