Yes, under limited circumstances.
To delete a requisition in SCView, there are conditions that must be met.
For a standard user:
The requisition must be in draft status. Once the requisition has been submitted (even if it was returned), it can no longer be deleted. If the requisition is in draft status, you can delete by right clicking and selecting "Delete".
For an approver:
If the requisition is in draft status, you can delete by right clicking and selecting "Delete".
If the requisition is in your workflow queue and you have permissions to delete, you can delete (must have Search privileges or be listed under "Items I affected" on the Requisition manager page).
If the requisition was returned, you can delete with delete permissions.
For an Admin:
As long as the requisition has not reached the Submitted to USAS status and you have given yourself delete privileges, you will be able to delete from the requisition manager. You can do this by selecting the requisition and selecting "Delete" from the right click menu.