You have several options to make all pickers on the page to have given property set.
1. Use ASP skin
and set the property there.
2. Wrap the Picker control in your custom/user control and use it instead of the picker in every place in your page.
3. Inherit the picker to your custom class and override the property or set the value in its constructor.
4. Use ControlAdapter
to set the given property for all pickers in your page.
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