Change item during PO receipt (P4312)

I am trying to accomplish the following: enter a stock purchase order for a (generic) item X. The delivered product is item Y which in general is a variety of X.

The standard way of handling this would of course be to change the PO first from item X to Y and then perform the receipt.

However, in our situation during the harvest season there is really no time to follow this process. Does anyone have a suggestion how to handle this type of receipt?

Although P4312 allows to change the itemnumber the receipt will be booked on the original item number.