This report summarizes the results of sweet corn variety trials conducted in 1978. Coordinated trials of early cultivars was conducted at Trenton, Simcoe and Harrow. There were 4 reps of 10 cultivars and 2 reps of 15 cultivars. Cultural problems reduced the replications at Harrow and data were not obtained on some cultivars. Additional Observation trials -2 reps- at Simcoe included 64 commercial cultivars, 36 experimental hybrids submitted for trial and 57 experimental hybrids produced at the Horticultural Experiment Station, Simcoe. Severe drought affected some of the observations trials at Simcoe by increasing heat units.