This paper considers a hypothesis that Diaporthe (Phomopsis) spp. on herbaceous weed species were the initial inoculum, which, in the early 1980's triggeredihe epiphytotics of the sunflower disease caused by the fungus Diaporthe (Phomopsis) iitiortniquit. ldet. et al., in the Vojvodina Province. A ten-yeâr study on more than 5 herbaceous weed species, conducted in 40 locations, found 18 Diapontophylla and Phomapsis isolates. Correlation bêrween individual weed species populations and the frequency and intensity of occurrence of disease symptoms, ascomata, and conidiomata was low. A separate analysis studied the reaction of sunflowers to two of the three Phomopsis species isolated from Kanthium ita1cun Moretti. The conclusion that the extensive præencn oi Phomopsis helionthi on diseased sunflower plants in the Vojvodina Province is solely responsible for epiphytotic outbreaks of Phomopsis is still valid.