Catalyzes the NAD(+)-dependent oxidation of geraniol to geranial, playing an important role in the biosynthesis of neral, an alarm pheromone. Cannot use NADP(+). Also acts as a farnesol dehydrogenase by catalyzing the oxidation of (2E,6E)-farnesol to (2E,6E)-farnesal, with lower activity compared to geraniol dehydrogenase activity. (2E)-geraniol + NAD(+) = (2E)-geranial + H(+) + NADH (2E,6E)-farnesol + NAD(+) = (2E,6E)-farnesal + H(+) + NADH Binds 2 Zn(2+) ions per subunit. Optimum pH is 9.0. Optimum temperature is 25 degrees Celsius. Monomer. Belongs to the zinc-containing alcohol dehydrogenase family.