Board Thread:Questions and Answers/@comment-67.253.171.246-20130526182246/@comment-5319459-20130526193810

Planters will not plant sugercane as a Harvester will never cut the entire plant down, instead, it will only remove the 2nd and 3rd blocks. After that, the sugercane can re-grow (fertilisers will not work on sugercane).

So all you need for a sugercane farm is the Harvester.