9 min read

The Cropwalker - Volume 2 Issue 23

Always read and follow label directions.

June 2019 Complimentary Issue; to become a member and receive all issues, sign up at:


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.

Crop Conditions

Weather - we had a string of 3 days or so last week where a lot of crop went in. Many acres were planted under less than ideal conditions.  Wheat is from flag leaf to almost done pollinating. Fusarium head blight risk is high. Lots of Prosaro and Caramba being applied. Aerial application is not very effective to control fusarium head blight. Cereal leaf beetle is showing up in some acres in Grey county. Other areas of historical CLB infestations should be watched. Threshold is 1 larva per stem. Average wheat yield will be down as a lot of acres intended to be burnt off are still living.  Corn - planting is over 90% complete. Intended acres is down. Earliest is 6-8 leaf stage and growing fast. Watch your herbicide choice as far as corn stage. Soybeans – from first trifoliate to in the bag. Overall probably about 80% of Ontario’s soybeans are planted. Forages - first cut off on many acres where forages are a main crop. A lot of fields with very poor yields where alfalfa died out. (More below). In uncut fields grasses are well headed out and quality of feed is low. Weed control (notes from Ian MacDonald OMAFRA “We are at a point in the year when temperature inversions are more likely leading to greater potential problems from the growth regulator type herbicides. Using a bottle of baby powder in the field can give applicators an indication of whether conditions for this are occurring. Puff some powder into the air. If it dissipates all is well, but if it stays suspended, then spraying is risky. Follow the product label directions for the phenoxy and dicamba products to the letter to avoid problems.”


Unseeded acres Benefit (USAB)

Agricorp is being very understanding. You need to talk to your local adjuster to figure what you can do. In some areas we are past the date for insuring corn. You can still insure soybeans. But some growers do not want to plant any more soybeans. Ask if you can collect you USAB for corn and still plant corn. This corn would not be insured. Ideally you could harvest this as silage. Or with an open fall it could black layer later this year. Failing that you might have to leave it out all winter and harvest next spring as dry corn. In 1992-93 we did that on acres that had no insurance. The corn came to 22-23% moisture in February. By May it was down to moisture of commerce. Bushel weight was very low. Feed quality test that were done by feeding to pigs showed that feed conversion was very good. There was no Fusarium in the corn that year. Other option is to take the USAB and plant a cover crop. This cover crop can be harvested. If in a livestock area you could have a market for your cover crop. Probably best option for a cover crop is oats. Should be able to buy feed oats or some oats that someone has on farm for $300/tonne or less. Seeding at 80-90 lbs/ac gives a seed cost of $12/ac. You will have to spray with a fungicide for rust control. If growing for forage you need a minimum of 40-60 lbs/ac N. This N can come from manure. (notes from Ian MacDonald OMAFRA “if you are thinking about using USAB. Growers do not have to wait until the planting deadline to decide to take USAB. Keep in mind that USAB doesn’t kick in until something else has been planted; the original crop is protected under production insurance until it is replaced. If conditions prevent reseeding a crop, a 0 tonne/acre yield on the production insurance applies. Where the conditions prevent you from planting your planned acreage of normal crops for your operation, you are not forced to try and plant another crop before claiming USAB”

Poor Forage Fields

A lot of fields with poor forage stands. Alfalfa has died out and grass is left. If the main grass was timothy or brome, there will be very little grass in future cuts this year. Once these grasses head out there is little regrowth. If the grass is orchard or ryegrass you can increase yield by applying 60-80 lbs/ac actual N. Alternatively you can no till oats into the existing stand. If you get moisture (which we seem to be able to do), you will have a decent cut in 6-8 weeks. You could see other crops like millet, sorghum or sudan/sorghum, but the seed of most of these crops is sold out. There is a suggestion to plant soybeans for forage. You really have to know what you are doing with this option. As OMAFRA forage specialist Christine O’Reilly said, “it takes growers about 4-5 years to figure out how to harvest soybean for forage. This is not the year to try to figure this out on a large acreage.”

Corn leaf burn with 28%

There is and will be leaf burn with 28% N applied post emerged. Typically, the burn looks worse than it is. You might be able reduce the amount of tissue damage by cutting 28% with water. (please let us know your experience by cutting 28% with water) Apply in or right before a rain (shouldn’t be hard this year) You can switch to a dry product, however a lot of 28% has been purchased so switching may not be an option. If you can use Y-drops or stream between the rows that will make a big difference. Consider using Agrotain to reduce N losses.

Nozzles you could use. Some growers flat fan on up to 50 gal/ac with herbicide up to the 2-3 leaf stage. Regardless of whether you use 20 or 50 gallons, the effect on the corn crop will be similar to a hard frost as far as leaf tissue goes. Larger droplets (very coarse to extra coarse) may reduce the amount of injury, could possible see a reduction in weed control as well.

Other growers have asked about using streamers (none of which should be used to apply herbicide). Streamer or Chafer bars will have the least amount of injury. They are not sensitive to variations in height, and do not overlap. Phil Needham suggested to avoid injury in the whorl, ensure the corn is less than 4” tall. On a 20” nozzle spacing, there is a stream of N about every 4”. A 3-hole streamer nozzles have the next least amount of injury but will be more sensitive to variation in height. 7-hole streamers with have the largest amount of injury, but the least effected by height. Strongly consider other options than a 7-hole streamer if past the 3-leaf stage.

Pictures from www.needhamag.com

Picture 1 - Chafer bars are not affected by boom height
Picture 2 - 7 hole streamers have 100% overlap
Picture 3 - Multiple streams increase risk of plant tissue burn

Problem weeds in corn

Following is some suggestions. There are a lot of options for all these weeds. Talk to your dealer and they may have another option.

Perennial sow thistle – use Marksman at highest rate possible in non-RR corn. Rate is dependent on corn stage. Once the corn is past the 5-leaf stage, consider using Distinct up to 6 leaf...  Otherwise highest Roundup rate possible in RR corn.

Horsetail – Broadstrike does a better job than any other product. You can use Broadstrike on emerged corn. You cannot use Broadstrike on emerged soybeans.

Glyphosate Resistant Fleabane in Corn

Acuron up to 6 leaf, Marksman up to 5 leaf, Distinct up to 6 leaf, Engenia/Xtendimax up to 5 leaf, Pardner + Atrazine 4-8 leaf.

Tufted Vetch in Corn– Distinct or Callisto in conventional corn has been proven to be the most effective. Callisto, or Dicamba can be tank-mixed with glyphosate in Roundup Ready. (do not tank-mix Distinct with glyphosate). Late post is ideal for maximum kill, will require a two-pass approach to avoid significant yield loss from annual broadleaves.

Can I Tank Mix Volunteer Corn Products with Clean Sweep?

Although not a registered tank-mix, it is safe to mix Assure II or Venture L with Clean Sweep. However, at Clean Sweep timing the volunteer corn is not usually up enough to get adequate control. You will likely have to spray a second time due to later flushes. If using Assure II, you must keep the rate at 200 ml/ac. (Alone, Assure II will control corn with 150 ml/ac). You would consider adding Assure or Venture if the grasses are beyond the Clean Sweep label.

Volunteer Corn Control

Inter-row cultivation is the only way to remove volunteer RR corn from your RR corn crop. In RR soybeans, plan to add Assure at 0.15 L/ac + Sure-mix or Venture at 0.24 L/ac to your glyphosate pass if last year’s corn was RR. In IP soybeans, you will likely have to make a special trip with Assure or Venture to take out the volunteer corn. Another option that is new to the market is Statue from Nufarm. The active clethodim has been marketed in the past as Select, but has an improved surfactant.

What Causes Manganese Deficiency? – Mn is very reactive in the soil. It is taken up as the Mn++ ion. If there is air in the soil this Mn++ ion quickly changes to the unavailable manganese oxide form. As the soil warms it releases Mn from organic matter. With cold soils very little is released. Cold soil also means roots are feeding shallowly where there is less available Mn. Some years the soils warm up fast and release Mn from organic matter. If the soils are warm and airy Mn converts to the unavailable Mn form. Colder, wetter clay loam soils with a pH above 7.5 will be more prone to Mn deficiency. It is not uncommon in soils above 7.5 to have a 0.8 soil pH fluctuation during the season. We are also taking more Mn from the soil with higher yields.

Foliar Micronutrients

You have decided that you need to correct a manganese deficiency but are unsure on what product to use. There are multiples of foliar fertilizer products on the market. These can be segmented into a handful of categories, “Crop-Lift” – are typically shot-gun products that contain multiple nutrients, and possibly a growth enhancer, but not enough of any one to correct a micro-nutrient deficiency. “Crop-Segment” – type products are designed for a specific crop or species. Depending on the deficiency or crop requirements, there may or may not be able to correct the symptoms. “Elemental” type products typically contain a single micro-nutrient, that when applied at a high enough rate can correct or reduce the effects of a deficiency. When correcting a nutrient deficiency, ensure the product is up to the task.

Do your plant stand counts!

With the on-set of growers wanting to use VR seeding, you need to have a baseline understanding of what your population is relative to seeding rate. This is where germ vs. seed mortality comes into play. Not all fields or even areas of the field with have the same seed mortality rate. Germination rate is the number of viable seeds. Mortality rate is the number of seeds that germinated but didn’t make it. Even if you plan on flat rating seed for the fore-seeable future, long term there will be farms that require higher seed drops than others. What’s your number?

Late Winter Wheat Stands

If there is one thing growers can do in the fall of 2019 for late planted winter wheat, it is to increase the seeding rate. Still seeing too many fields of wheat where the seeding rate was not increased as the fall progressed.

Dicamba Rates

A quick review on dicamba rates as we enter post-emerge spraying of both corn and soybeans. Also, a timely reminder that nozzles with extremely-coarse or ultra-coarse spray droplets are required for post emerge application of dicamba to Roundup Ready 2 Xtend soybeans.

Table 1 - Post Emerge Dicamba Rates

"A lot of things that work for you also work against you. Inertia is a great example. If you keep doing what you've always done, you're going to get the same results you've always gotten. Decades get wasted expecting different results from the same inputs."

- Shane Parrish