Central Ontario Crop Consultant’s Meeting Minutes – May 19th, 2015


A tremendous amount of field work has taken place over the past couple of weeks. Corn planting is 90-95% complete, soybean planting is 70% complete. Corn emergence has been good.  Soil conditions and moisture up to now have been excellent. Concern now is planting into dry soil conditions and need to plant deeper,. Many are reluctant to plant soybeans deeper than 1- 1.5 inches because of crusting and other  emergence related concerns. Low temperatures and risk of forecast for frost are a concern for herbicide/fungicide application in wheat & emerged crop. Refer to discussion below and links to articles.  A gentle all day rain would be welcomed and  is needed in many cases to activate pre-emerge herbicide applications. Heavy rains through the  Peel Region resulted in crusting and emergent issues.


Corn planting is essentially complete and emergence to date has been good.  Activation of pre-emerge herbicides is a concern. For many pre-emerge herbicides it will take 12 to 18 mm(0.5-0.7 inchs) to activate.  The pre-emerge herbicides are not expected to deteriorate, resulting in continued control for new emerging weed.  Many labels state that activation by rainfall is required within 5-7 days or need to lightly incorporate (eg harrows) or make decision to spray. Once grass escapes get beyond 2 leaf stage or broadleaf weeds the 4 leaf stage pre-emerge herbicide activity (reach-back) is unlikely. Broadleaf weeds are much more competitive than grass weeds at similar density.  Significant amount of corn in the 1-2 leaf stage.  Critical weed free period for corn is 3 to 8 leaf, so lots of weed control needs to occur shortly. Clean-up of weeds in glyphosate corn will be simple. Some issues with corn planted too shallow, needs to be a good 1.5 inches deep.

Monsanto conducted 105 side by side trials evaluating yield response with neonicitinoid seed treatment. Average yield increase with neonic was 6 bu/ac. Yield increase was greatest on sandy soils, much less on heavy soil types. This response is similar to results they had seen in trials 10 years ago with Poncho 250.


Soybean planting 70-80% complete, with generally good emergence.  Soybean tolerance to frost is better at  cotyledon stage than when they are just hooking through the ground.  The recent cold nights may have helped in the hardening process, increasing tolerance to a frost. Cool days and nights increase hardening over alternating warm days, cold nights. Once true leaves emerge (V1-V2) soybeans are less tolerant to freezing temperatures for any extended period of time.  Lots of patience will be needed to assess damage. Wait 3-5 days before assessing damage, examining plants for new growth.

Most emergence issues related to planting shallow (<1 inch) and planting too fast. Some of this is related to no-till drills that are not really no-till resulting in poor seed placement or handling of residue. Row cleaners or cutting coulters ahead of opener important in no-till and reduced till situations. Corn stalks and root balls have been a challenge to handle this spring, particularly where stalks were chopped.  The problem with chopping corn heads is because some planters cannot deal with the mat of residue and it causes lots of hair pinning. In no-till or reduced til, better to leave the stalks standing, fields dry off earlier and help to melt the snow and allow soils to dry out sooner.  Some chop the stalks because they are concerned about stalks going through the combine, but if you dont like it, roll/pack the soils after planting to flatten stalks.  Increased number of growers switching to planters 20-22 inch, for planting soybeans.

More growers are putting starter down with their soybeans, mostly MAP but also fertilizers containing potash. Soybeans with potash in starter increase risk of seedling injury, particularly on low organic matter soils or in dry spring. Most growers are using an inoculant and using two inoculant forms on virgin ground. Bigger demand this year for pre-inoculted seed.

There were a few reports of problems with planting high moisture seed (16%) which can be ‘gummy’, causing issues with metering and mechanical damage to seed in seed cups on drills. Very uncommon to have seed this moist. The problem likely relates back to poor harvest conditions last fall. Seed germination tests this spring have generally been very high.

Dave Hume reported they continue to conduct research trials with new inoculant technologies. Last year pre-inoculants gave a 4 bu/ac response vs none on history soybean soils. Also doing a lot of trials with neonic replacements from DuPont.


UAN applications in wheat last weekend causing some leaf scorch. Many of the poor stands of wheat were related to late planting and/or poor soil conditions, shallow seeding, slot planting. Many ‘false hopes’ with challenged stands that initally apperaed okay, but had poor developed root system.

Spring cereals look excellent. Everything that was intended to be planted was planted.

Herbicide/Fungicide application during cold weather

Lot of concern with spraying herbicide/fungicide in wheat with cold temperatures/frost. Biggest concern is spraying day before, day of or day after very low temperatures or forecast frost.  The meeting had low turnout of  pesticide company representatives so following the meeting several other agronomists were asked to weigh in on the topic. Consensus was that as long as night time temperatures are above freezing at night, continue to spray. “We rarely see poor weed control from wheat herbicides applied during cold periods, just slower kill. I’m not sure why perople worry about 5 C for biological activity. It will warm up soon, and weeds won’t have metabolized the herbicide” (Peter Johnson, Independant Crop Consultant).  Increased injury could result from applying fungicide with the herbicide. Melody Robinson, U of Guelph conducted trials  in 2009-2010 evaluating winter wheat tolerance to mixtures of herbicide and fungicides applied under cold conditions early and late at growth stage Zadoks 37-38. See the full article in Candian Journal of Plant Science: http://pubs.aic.ca/doi/abs/10.4141/cjps2012-181

The research showed that Folicur and Dichloroprop/2,4-D was the most injurious combination, followed by Bromoxynil/MCPA with folicur. “The likelihood of tank-mixes causing injury was greater when they were applied late. The fungicide tebuconazole (Folicur) caused the highest level of injury when mixed with herbicides and injury was particularly high with the dichloroprop/2,4-D.”  The benefit gained by adding the fungicide will be lost if injury occurs. If growers are concerned, leave out the fungicide, but weed control should not be delayed unless freezing temperatures are expected.

Corn Post-emergent Herbicde Application during cold weather/frost

Mike Cowbrough, OMAFRA provided the following link for an article he wrote article last year and posted to fieldcropnews: https://fieldcropnews.com/2013/05/frost-damaged-corn-and-herbicide-applications/ 

Weeds in corn are small, and generally populations are low, so other spraying will take priority (eg winter wheat). Even where pre-emergent herbicide does not provide level of control expected because of lack of rainfall to activate, emphasize that weed pressure is still much less where need to respray.  Need to wait on broadleaf weeds to develop true leaves and grasses more than one leaf , are actively growing and have more leaf area to hit.


Harvest to begin in south west next week. Alfalfa is expected to be ready for 1st cut later next week/1st week of June. Taking a cutting last fall during critical harvest period, hurt stands this year (again!).  The cool nights and sunny days have been perfect for alflafa resulting in higher than normal portion of alfalfa:grass expected in first cut.


  • Agricorp is still receiving some calls with damage claims, 1150 in total with Lambton county having highest number of claims. About 11% of acres of wheat insured have damage reports. Not all damage reports turn into claims.
  • Online acreage reporting is now live as of last week.  Growers encouraged to try online reporting to save time and reduces the heavy volume of calls near reporting deadline.
  • Still some acres of 2014 corn without yield reports

Upcoming Dates


Please direct any questions, comments or agenda items to either:

Brian Hall | 519-271-0083 | brian.hall@ontario.ca . or

Ian McDonald | 519-239-3473 | ian.mcdonald@ontario.ca