The turn in Low Limit Omaha often plays itself, that is to say that on the turn you usually know whether you still are winning (or have a good draw to a winning hand) or if you are beaten and you can simply bet accordingly.

If you had a strong high hand on the flop that contained two low cards and a non low card comes on the turn that does not hurt (or better yet, helps) your high hand then this is the time to make people pay to draw out on you.

Let's say for example that you were playing the following hand

Ace of Spades King of Spades Jack of Diamonds Ten of Diamonds
Hole Cards

and you flopped the following hand

Seven of Clubs Nine of Clubs Eight of Spades

it may be more profitable for you to wait until the turn to show aggression to save yourself money and aggravation.  If a "blank" comes on the turn (neither a low card, a club, nor a ten) then you can get extra money in the pot on the turn when the bets are double sized and the draw out potentials are smaller with only one card to come.  Suppose the next card produces a board of:

Seven of Clubs Nine of Clubs Eight of Spades   Queen of Diamonds
Flop   Turn

Your nut straight has morphed into a different nut straight. Now you are mainly worried about a club or a 7 8 9 Q to fall on the river, however your odds are sufficient at this point to pump the pot, if a low card comes you will only get half the pot but if it is a non club low card you'll still be making money on your bets and raises here, if a low card does not come then you have excellent odds for a high hand scoop since any non club high card that falls will leave you winning high.