Using a simple variational method, we have studied the zero field electrical resistivity ρ(T ) of rare earth manganites doped with alkaline earths namely Re 1−x AxMnO 3 which exhibit colossal magnetoresistance (CMR), metal-insulator transition and many other poorly understood phenomena. We take the two band model Hamiltonian for manganites in the strong electron-lattice Jahn-Teller (JT) coupling regime. This model is constructed for the doped manganites which exhibit colossal magnetoresistance (CMR) involving a broad spin-majority (eg-spins) conduction band (b-band) as well as nearly localized spin-minority (t 2g -spins) electron states ( -band). Two band models involving itinerant and localized states were also suggested earlier by both experimentalists and theorists. We have also studied the temperature dependence of electrical resistivity ρ(T ) at H = 0 of these materials and observed the role of the model parameters e.g. local Coulomb repulsion U , strong ferromagnetic Hund's rule coupling J H between eg and t 2g spins and hybridization V between -polarons and b-electrons of the same spins on ρ(T ). We find from the resistivity results that as the temperature is lowered below a critical temperature Tc (∼ 200 K), there is a sudden drop in electrical resistivity ρ(T ) at H = 0 resembling with the key feature of many CMR compounds like La 2/3 (Pb, Ca) 1/3 MnO 3 and (Sm 1−y Gdy) 0.55 Sr 0.45 MnO 3 at y = 0.5. This anomaly in ρ(T ) arises from the onset of magnetic ordering at 200 K and vanishes on increasing V or J H value. T -dependence of ρ(T ) is metallic-like below Tc (∼ 200 K), above which it shows insulator/semiconducting-like behavior.

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