blog posts Depending on when El Niño turns into La Niña, the effects on the growing season will vary. Mar 28, 2016 10:45 am by Ag ProfessionalIllinois in the News Share on Facebook Tweet Email Images Ag Professional (March 28) - “History suggests that a transition to La Niña by June, July, or August may measurably raise the risk of corn and soybean yields falling below trend,” Illinois ag economists write. Share on Facebook Tweet Email