Ridgetown Breakfast Minutes April 10th, 2012

Included: crop status, wheat, glyphosate resitant weeds (status and control), weed control update (Peter Sikkema).

Synopsis: Very little corn planted as of April 10th. Many growers will start this week. A few “experimental” soybeans have been planted. The wheat in this region looks tough, with too many areas suffering from wet feet.  Considerable spring grain planted into wheat fields where growers are trying to maintain the rotation or need straw.  Sugar beet planting is complete, but some reseeds due to the March 30th frost are required. A few acres suffering from a light crust (sugar beets are very sensitive).  Carrots and onions, potatoes planted.  Tomato fumigation underway.  It is dry: the Thames river is currently at summer time levels.

Wheat: Nitrogen applications will wrap up this week.  In hardest hit areas 50% of the crop is roundup ready and will be seeded to another crop.  Other areas are quite acceptable. November wheat looks better than October wheat in many cases. The crop continues to suffer from frost and cold temperatures. Manganese deficiency is an issue in history fields. Applications of MnSO4 have been helpful, even with little healthy green tissue on the crop. Aerial seeded wheat was a clossal failure, even though everything was done right.

Update from Peter Sikkema: 48 fields have been confirmed with glyphosate resistant giant ragweed, mostly Essex with one in Kent and one in Lambton.  77 fields have been confirmed with glyphosate resistant Canada fleabane, which has spread faster and more broadly than giant ragweed.  Counties confirmed with resistant fleabane include Essex Kent Lambton and Elgin.  Every field of RR corn and soybeans needs a residual herbicide, not for giant ragweed and fleabane, but to prevent weed number 3 and 4 from becoming resistant!  There are lots of excellent options, so no excuse not to use something.  The soil applied herbicides should have broad spectrum activity, that is activity on both grass and braodleaf weeds.

Resistant fleabane also has cross resistance to group II herbicides, meaning that Firstrate (the product of choice for fleabane escapes) is not effective in some fields.  It is essential to start with a clean field.  Based on recent Ontario research, Glyphosate + 2,4-D Ester would be the preferred choice for the control of giant ragweed, but 2,4-D Ester is not registered preplant in soybeans.  A submission for registration has been made to PMRA, based on work done by Dr. Sikkema.  This is a common treatment in the US. (0.5 lb ai of LV Ester 7 days before planting).  Hopefully registration will come through shortly.  Glyphosate + Eragon + Merge is preferred for the control of Canada fleabane. Glyphosate + Lorox does a good job but is very expensive.  Liberty Link soybeans are another option, but it is still essential to start with a clean field, as Liberty is only effective if the weeds are small (<3″).

Weed management is weed specific.  While the bromoxynil/MCPA products are the standard on wheat, they do have some weaknesses.  If chickweed or wild carrot is an issue, Refine is a better choice.  If cleavers, Trophy.  If dandelions, Estaprop or Infinity.  With chickweed, more growers should consider fall applications of Refine.  Even reduced rates of Refine in the fall gave excellent control of chickweed the following season.  Similar things can be said about the corn and soybean herbicde program: for example, if wild carrot is the issue in soybeans, Classic is the product of choice.  Be sure to match the herbicide program to the weed spectrum.

Unexpected soil residual: Venture was shown to have considerable soil residual in trials last year.  If taking a first planting of corn out because of damage, and replanting to corn, Assure II appears to have much less soil residual at volunteer corn rates and would be the product of choice.

NOTE: A huge vote of THANKS to Bill McDonald! Bills is retiring from Agricorp as of April 18th due to health issues.  Bill was a regular at our meetings, and always had excellent input.  All the best Bill, and you are always welcome at these breakfast meetings!

Next meeting: April 24th, Ridgetown, 7:30 am sharp start to the discussions.

If you have questions about these minutes please contact: peter.johnson@ontario.ca