  We develop an ansatze of the sigma enhancement of the I=0, L=0 $\pi$-$\pi$
scattering amplitude as arising from a low-energy glueball pole. Using this
picture we estimate the $\pi^0\pi^0$ to $\pi^0$ branching ratio for the decays
of the Roper resonance, which we previously found to be a hybrid in our QCD sum
rule calculation. We find that the sigma decay might be a good signal for
gluonic components of hadrons.
