Dealing with agricultural wages so that real Americans (Tm) will work at farms.?

One of the issues with illegal immigration is that American farmers pay wages so low that only illegal immigrants will work for them. Lots of the people who think that people ought to pay a higher "living wage" (whatever that means since many of these illegal immigrants could stay here for years and not only live on that wage but wire money back home every few months). So how about people set up some sort of certification programs and Co-Op where all the farmers who supply their crops have to pay an agree upon "living wage" and certify (with inspections) that they hire only Americans or legal workers. Then we'll see how the prices of the food will work out since most farmers are making a very slim profit margin already so the prices are of course going to p to the consumers.