Complex sentence: As of April 2014 maize and soybeans resistant to 2,4-D and glyphosate had been approved in Canada, and in September 2014 the USDA approved the same two crops.
Split into simpler sentences: As of April 2014 maize and soybeans resistant to 2,4-D and glyphosate have been approved in Canada. In September 2014 the USDA approved the same two crops.