who was the pitcher who struck out Pete Rose to end his 44 game hit streak in his last at bat?

On August 1, 1978, Pete Rose went 0-4 versus the Atlanta Braves. Rose walked in the first inning, lined out to the pitcher in the second inning, lined out to the shortstop in the fifth inning, lined out to the third baseman in the seventh inning, and struck out in the ninth inning

Pitchers were

Larry McWilliams 1-5 innings

Dave Campbell in the sixth

and Gene Garber for the final three

So to make a long answer short...Gene Garber.

Listening to the radio you'd of thought it was a World Series at bat. Gene Garber was pitching for the Braves back then. Being a Reds fan that summer of '78 was hard,you could tell the "Big Red Machine" was about out of gas.

Gene Garber

Gene Garber