A manor refers to any property owned by the lord. Anything produced within its confines remains the exclusive property of the lord.
If you wish to be an agricultural producer, first you must buy a

and place it onto a monster. This can be easily accomplished while targeting.
When the monster, dies you will harvest a crop from its body. To harvest a crop, just target the corpse and use the harvester - if you don't have one, I'll happily sell you one! These crops are important to the manor, so after you've harvested them, bring the

to me!
I will then appraise them and give you an appropriate reward! I'll tell you about the rewards later...