Peter Dillon says:
"Should the beekeeper reject this situation, claim partial secondary
 pollination fee or accept this as fair play and normal.
 I realise that it is up to the beekeeper to form an agreement with the
 grower - but when neither side can call upon "standard" practice and
 have different opinions on what is best, I suggest that it be thrashed
 out in public rather than something become standard and cause underlying
 resentment for one side or the other."
>>>>>>>>>>>>>>>>
Although I have not rented or leased out any of my beehives for pollination purposes, I have thought about doing do.  As a beekeeper, here are some of my feelings on this subject:

As you say, it is up to the beekeeper to form an agreement with the grower.  I would not want the grower doing anything with my bees without me knowing about it and me agreeing to it beforehand.  An exception I can think of is if the grower moved the bees to keep them from getting killed, then I think I wouldn't mind that.

If I were going to provide bees for pollination, I think the grower would expect me to deliver them and place them where he/she wanted them to be.  The grower would not come to my place with a truck and pick up the hives and then set them out where he/she wanted them.

I think that for sure I would be unhappy to find out after the fact that a grower had moved my bees without informing me and used them in a way that was different than what was originally agreed upon.  Modifications to the agreement should be discussed and agreed to by both parties before action is taken to move hives to a new location.

If your agreement is that during a particular time period the hives are at the disposal of the grower to move them wherever they want them or need them or deem appropriate if they change their mind, then it should be fine.

If your agreement is to pollinate a crop in particular fields and the crop has been pollinated, then I think the grower owes the beekeeper an additional fee for pollinating an additional crop in a different area.

I would think it all depends upon what is written into the agreement and an assumption that anything that is not written in the agreement (a change to the agreement) is not to be done by either side without consulting, discussing and both participants agreeing to modify the contract.    It just seems to me that common courtesy and decency demands that one side not try to take advantage of the other side.  The bees are not the grower's property unless he/she buys them, and as such, nothing should be done with them or to them without the consent of the owner/beekeeper.  Is the grower getting an additional advantage by moving the bees to an additional location?  Then the beekeeper should also benefit from that additional advantage the grower has received.   That would only be fair to both sides in my opinion.  Otherwise, if the first crop's pollination was completed, then the beekeeper potentially could have moved the bees to a different contract for an additional fee.

Layne Westover
College Station, Texas