Complex sentence: From 1978-1983 he was Vice-President of the International Society for Plant Pathology and from 1980-1983 President of the Australasian Plant Pathology Society.
Split into simpler sentences: From 1978-1983 he was Vice-President of the International Society for Plant Pathology. From 1980-1983 he was President of the Australasian Plant Pathology Society.