To extend the shutter speed in daylight use the following ...
Lowest ISO possible to slow down the sensor sensitivity
Smallest possible aperture to reduce light coming in (use aperture priority)
Use Neutral Density (ND) filters that reduce the amount of light entering the lens without changing the colour balance. I use ND8 which slows down the exposure by 3 stops, to provide motion blur in daylight.
You can even use ND10 filters to provide immense amounts of motion blur, right to the extent that any moving objects totally disappear.
Here is an example of my own, using an ND8 at sunset to lengthen the exposure and cause motion blur to the extent that the sea became a mist ... http://www.thetrueshot.com/Photographs/Pages/Sunset.html#26