Volume 3, Book 34, Number 406 :
Narrated by ‘Abdullah bin ‘Umar (radiallaahu `anhu)
Allah’s Apostle (sallallaahu `alayhi wasallam) said, “If somebody sells pollinated date palms, the fruits will be for the seller unless the buyer stipulates that they will be for himself (and the seller agrees).”
If pollinated date-palms are sold and nothing is mentioned (in the contract) about their fruits, the fruits will go to the person who has pollinated them, and so will be the case with the slave and the cultivator.
If someone is selling a pollinated crop/garden or a sown land, and the contract doesn’t mention anything about the fruit of that particular yield, it goes to the seller/owner by default. But if the contract stipulated otherwise and both parties agreed to it, then the buyer can have the yield to himself. That’s it, more or less. :)