Soybeans: Once soybeans have emerged there are limited options for fleabane control in conventional or glyphosate tolerant varieties. If the fleabane is not resistant to group 2 herbicides, First Rate is an option. As the dry weather continues, growers may want to consider deeper planting depths (2-2 ½ inches) to ensure soybeans are planted into moisture. There may be some emergence issues in areas that received spotty, hard rainfall. Reports of soybean emergence on heavy corn residue trash looking poor, while emergence on tilled ground looks good. Past Ontario research has shown that the difference in yield between no-till and tillage is 2 bu/ac on average. There is a shift to more tillage in soybeans because of emergence issues as well as the soil drying out sooner allowing growers to get into fields sooner.
There is some replanting under way on clay soils. Deciding whether it is worth replanting a poor stand can be difficult. Plant stand reductions are rarely uniform, which makes a decision to replant more challenging. Often it is best to treat parts of a field separately. Do not assess a poor soybean stand too quickly, since more seedlings may still emerge. Fields with a plant reduction of 50% do not need replanting if plant loss is uniform and the stand is healthy. Numerous studies and field experience have demonstrated that keeping an existing stand is often more profitable than replanting. Replanting gives no guarantee of a perfect stand. “Do not replant a plant stand of more than 222,000 plants/ha (90,000 plants/acre), in 19 cm (7.5 in.) row spacings on most soil types. Very heavy clay soils need a minimum of less than 250,000 plants/ha (110,000 plants/acre) before a replant is worthwhile.”
Weed control: Peter Sikkema reported that in his research trials the annual ryegrass was better controlled in 2018 compared to 2017 with glyphosate and assure. Glyphosate and group 2 herbicides are also showing promising control. Peter also reported that the University of Toronto confirmed a second mode of resistance to Group 14 in waterhemp. Waterhemp in Essex County was found to be genetically identical to waterhemp found in Missouri; however, the waterhemp found on Peele Island is found to be more genetically similar to historical waterhemp found in Ontario. There is a 30% reduction in the control of volunteer corn in soybean when Xtendimax and Engenia are tank mixed with Assure or Venture. Group 4 herbicides will antagonize group 1 herbicides when tankmixed. To overcome this the rate of Assure or Venture can be increased by 50%. A reminder that ammonium sulphate and older forms of glyphosate will also increase the volatility of dicamba when added to the tank so growers should avoid this practice. There are no good products registered for the control of buckwheat in IP soybeans. If buckwheat is a problem in IP soybeans growers can try herbicides such as Classic or Reflex.
Forages: First cut alfalfa is beginning in some areas where growers are looking to get four cuts this season. Growers should scout their fields after harvest for alfalfa weevil feeding. Fall rye is coming off with reports of lower volumes compared to other years. Quality is also being reported as going down as it was not cut soon enough.
Agri Corp Deadlines:
Unseeded Acres Reported: June 15th
Final Planted Acres: June 30th
Upcoming Event
Southwest Crop Diagnostic Days (Ridgetown Campus) July 4 or 5, 2018
FarmSmart Expo 2018 (Elora Research Station) – July 12, 2018
Eastern Ontario Crop Diagnostic Day (Winchester Research Farm) – July 19, 2018
Stratford Crop Technology Contacts:
Horst Bohner, horst.bohner@ontario.ca
Joanna Follings, joanna.follings@ontario.ca
Meghan Moran, meghan.moran@ontario.ca
Jake Munroe, jake.munroe@ontario.ca
Source : Field Crop News