  We study the effect of decoherence upon the neutrino spectra produced in
micro-quasar jets. In order to analyse the precession of the polarization
vector of neutrinos we have calculated its time evolution by solving the
corresponding equations of motion, and by assuming two different scenarios,
namely: (i) the mixing between two active neutrinos, and (ii) the mixing
between one active and one sterile neutrino. We have found that for the case
with two active neutrinos and large values of the neutrino-neutrino
interactions the onset of decoherence is not manifest. For the active-sterile
scheme decoherence becomes manifest if the strength of the neutrino-neutrino
interactions ($\mu$) and the ratio between the square-mass difference and the
energy ($\omega=\frac{\delta m^2}{2 E}$) satisfy the relation
$\frac{\mu}{w_{E=E_{\rm min}}}>0.1$.
