"Only 1 set of Deadlifts? Is that a typo?
Long answer: You're already squatting 3x/week of 3 sets of 5 and that hits a lot of the same target muscles as the deadlift. That, plus the fact that deadlifts are notoriously hard to recover from is why they are only for 1 set. Once they get heavy and you're going all out for your one set, you'll be so gassed that the very thought of doing two more sets will make you projectile vomit.
Shorter answer: No"


und dazu noch:

"Since this exercise is performed AFTER squats, and since squats can fatigue many of the same muscle groups, only 1 working set of deadlifts is required to achieve an appropriate training affect, and for most novices and even many intermediates, only 1 working set of deadlifts will be required to maintain steady progress in the exercise."

Quelle: http://startingstrength.wikia.com/wiki/FAQ:The_Program