  Starting from a spin-orbital model for doped manganites, we investigate a
competition between ferromagnetic and antiferromagnetic order in a
one-dimensional model at finite temperature. The magnetic and orbital order at
half filling support each other and depend on a small antiferromagnetic
superexchange between t_{2g} spins and on an alternating Jahn-Teller potential.
The crossover to a metallic ferromagnetic phase found at finite doping is
partly suppressed by the Jahn-Teller potential which may localize e_g
electrons.
