RoleManager enable and disable

Web.config

<roleManager enabled="true" defaultProvider="RoleProvider">
      <providers>
        <clear/>
        <add connectionStringName="connectionString" name="RoleProvider" type="System.Web.Security.SqlRoleProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
      </providers>
    </roleManager>


Can i enable or disable this roleMager from web.config. I need to disable it in one special example. Thx

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