  We consider the evolution of the Affleck-Dine scalar during D-term and F-term
inflation and solve the combined slow-roll equations of motion. We show that
for a typical case, where both the Affleck-Dine scalar and inflaton initially
have large values, in D-term inflation the Affleck-Dine scalar is driven to a
fixed value, with only a very slight dependence on the number of e-foldings. As
a result, there is a definite prediction for the ratio of the baryonic
isocurvature perturbation to the adiabatic perturbation. In minimal (d=4)
Affleck-Dine baryogenesis the relative isocurvature contribution to the CMB
angular power spectrum amplitude is predicted to be in the range $0.01-0.1$,
which can account for present large-scale structure observations and should be
observable by PLANCK. In a very general case, scale-invariance of the adiabatic
perturbations from the Affleck-Dine scalar imposes a lower bound of about 0.01
for d=4. For d=6 the isocurvature perturbation may just be observable, although
this is less certain. We also consider F-term inflation and show that the
magnitude of the baryonic isocurvature perturbation is fixed by the value of
$H$ during inflation. For typical values of $H$ the isocurvature perturbation
could be close to present observational limits.
