A survey of 67 commercial fields in 19 locations was conducted the southern Pampean region Argentina for Phomopsis stem canker sunflower (Helianthus annuus L.) between 2014 and 2019. total 210 plants having typical symptoms were randomly sampled, fungal isolation performed. Of 187 isolates Diaporthe that recovered, 94% showed morphological characteristics similar to D. helianthi, 3% gulyae, 1% ...