Palmerston Crop Consultants June 5, 2012 Meeting

Synopsis: Most areas received between 1-2″ of rain, although few areas (Goderich) only received 1/2 this amount.. Fungicide application to wheat is ongoing with most fields sprayed. Corn advanced for leaf stage. Populations of corn and soys generally excellent although those planted last 10 days variable. Watch for armyworm, alfalfa weevil, cabbage seedpod weevil(canola).

Wheat: Most fields have now received fungicide application. Watch for armyworm. Most reports of high populations have been in southwest region. However growers there that did not think they had a problem are surprised when fields have been checked. Scout now!. In applying fungicide at heading best to apply alone.  Not enough data to support any tankmixes with anything else

Corn: Most corn stands look excellent with good populations. Early April planted corn now at 7- 9 leaf and now being sidedressed.  Plant size is short for leaf stage. Some corn appears twisted due to rapid growth. The last corn and soybeans planted show uneven emergence due to moisture. In some cases this was related to fall tillage, mainly chisel plow.  Spring tillage on this land placed dry soil from ridges in valleys resulting in mositure variations at seeding depth. Common practice is to use a buster bar or leveling device in fall. Some replants due to crusting, mainly in Dufferin, Halton, Peel region. Some corn planted around April 18th, just before cold weather snap required replanting. Disussion on tillage to aid corn emergence.  Rotary hoe has variable success, but no-till drill operated shallow (3/4 inch deep) at angle or crosswise to direction of planting works much better. Also works for soybeans but operate at shallower depth. some fields of yellow corn appear lodged.  This appears to be due to rapid growth and root growth has not kept pace.

Forages: First cut yield about 2/3rds of normal. High alfalfa weevil populations in some areas, mainly Mount Forrest-Simcoe area. Some poor alfalfa stands were also fields cut during critical fall harvest period. Lots of interest in sudan-sorghum and annual forages to be seeded after wheat harvest. Oat or rye with pea mixtures are in demand, with oats in tight supply. For more information on spring cereals for forage forages go to   . The Ontario Forage Council has has good information available:

Soybeans: Emergence is excellent in most fields with few emergence issues due to moisture, seeding depth with older drills, or no-till where residue distribution was an issue. Some respraying where pre-emerge herbicide being used. In some cases it is surprising how little moisture was needed for pre-emerge herbicides to work.

Canola:  Canola is advancing quickly with most now 4 leaf to early flowering, Cabbage seedpod weevil populations have been low to date. Highest populations found in field margins. Threshold is 2-4 per sweep. Use caution when applying insecticide at flowering to protect area honeybees. Canola plant populations are lower than normal, and will require more management and have lower thresholds for flea beetles, weeds.

Agricorp: OMAFRA is investigating program to compensate growers for wildlife damage. Agricorp is recording damage reports and extent of damage. Growers with damage need to contact Agricorp to have field evaluated.  Wildlife damage by itself is usually never enough to place grower in claim position.

Weed Management:  Mike Cowbrough (via teleconference) led a discussion on weed management issues.

  • Corn weed escapes when corn is at 8-10 leaf stage. Dr. Sikkema’s data has shown that generally the safest products are glyphosate (RR corn), Callisto + Aatrex 480, Pardner. Phenoxy’s products (e.g. Banvel II, Marksman/Propero) are a concern and should be avoided.
  • Soybeans. In non-gmo soybeans targeting herbicide applications to weed stage is more important than crop stage. If one finds themselves having to spray at more advanced crop stages (5th trifoliate to flower initiation), Dr. Sikkkema’s research has shown that Pinnacle and Pursuit should be avoided as they cause significant crop injury while glyphosate, Basagran Forte, FirstRate have shown to be the safest while Classic and Reflex can cause injury but typically don’t reduce yields.
  • Annual bluegrass: continue to get more queries on this and other Poa species. There are  many different Poa and there susceptibility to herbicides varies. More research is needed to better understand how to manage these types of grassy weeds.
  • Scentless camomile (biennial or short lived perrenial). Tillage is best control. Second choice is glyphosate.
  • Weed identification and DNA barcoding project. University of Guelph has new project to collect DNA barcode information on agricultural weeds in Ontario. More information will be provided on how to submit samples shortly
  • Reports of glyphosate missing lambsquarter. Several likely reasons  for this. Dust created by spray equipment intecepting and deactivating glyphosate. Lambsquarter also excretes mineral salts onto leaf surface that creates a barrier to herbicide penetration. The salts build up over time, so older lambsquarter more resistant.   This is what gives leaf surface white mealy appearance. I hypothesize that because of this mealiness, spray droplets tend to roll off and are more difficult to penetrate leaf surface. Lambsquarter is one of the weeds that changes it’s leaf angle during the day, thus best time is afternoon. Unclear which adjuvants might improve control. Ammonium Sulphate used with Liberty(1 l/ac rate) will improve control of Lambsquarter, Velvetleaf.
  • Nutsedge. Callisto will provide some initial burn but control is only 50%, similar to Basagran.  Best control is glyphosate (2 l/ac) in RR corn.