  We study numerically and analytically the dynamics of defect formation during
a finite-time quench of the two dimensional Swift-Hohenberg (SH) model of
Rayleigh-Benard convection. We find that the Kibble-Zurek picture of defect
formation can be applied to describe the density of defects produced during the
quench. Our study reveals the relevance of two factors: the effect of local
variations of the striped patterns within defect-free domains and the presence
of both point-like and extended defects. Taking into account these two aspects
we are able to identify the characteristic length scale selected during the
quench and to relate it to the density of defects. We discuss possible
consequences of our study for the analysis of the coarsening process of the SH
model.
