The effects of immigration on fruit and vegetable costs?

I am not an economist and so lack the chops to sort out the battle of stats in this blog post. If someone who reads this is more competent to do so, I'd appreciate it. Vilsack's numbers on what cracking down on illegal immigration would do to fruits and vegetables seem high to me intuitively, but then Martin's seem quite low.

Also, an average consumer unit spends only $7 on fruits and vegetables a week? That seems quite low. Do I really wolf down salad like I am actually a rabbit?