The pineapple business in Hong Kong - any light to shed?

I've been working on the list of taxes etc levied in the first decades of the last century.  I was bemused to see that a Pineapple licence, costing $3 per acre is listed.  This in a miscelleaneous section - along with slaughter house and laundry licences ... but no other specific vegetable or fruit products have their own licence.  I feel that 'Pineapple culitvation in early Hong Kong' might make a nice little undergraduate disseration.