What I've observed, is that with the "tree based" crops, such as papayas and bananas in T2, and coffee in Trop, you get large, productive farms due to the slow crop development time.
The farmers plant, and plant, and plant some more while the crops are growing. Once they start producing as full grown trees, then you get the BIG payoff of the farms being super productive. Usually, there are more crops than can be harvested quickly. Later in the game, the farmers don't seem to plant new trees, as they can barely keep up with the existing ones. That may be why Frog City cut the number of farmers to 2 for the papaya and banana crops.
One thing interesting about banana crops, and I'm not sure if this is accurately relfected in the game, is that a banana tree only produces one crop of bananas. Then the tree is cut down. I visited a banana plantation in Jamaica, and the mature trees, aside from the bunches of bananas, had a single HUGE, stinky flower, that spawned a new plant. I'm not sure how multiple new plants are grown from a single plant.
Anyhow, our guide told us about the mortality of the banana tree after it had produced its bunches.
And for your useless trivia of the day:
single banana = finger
clump of bananas (like in the grocery store) = hand
many hands of bananas (many feet long) = bunch
So goes the Harry Belafonte song "six foot, seven foot, eight foot bunch!"