Palpatine/Sidious beating yoda into hiding on dagobah, i think not!!!
Yoda kills another sith lord and the evil energy inside him goes into a tree, posessing it if u will. It is the evil energy from dagobah that causes yoda to take refuge there, as the evil energy from the tree blocks out the force from yoda, so he can lay in wait for a certain skywalker, without palpatine/sidious sensing his presence, so he believes vader has killed him
i did not make this up, its on the star wars site in the databank!!!!!