Deporting illegals will not hurt agriculture. In fact, it will help stop the hideous working conditions and exploitation that Ceasar Chevez's Farm Labor Union once stamped out. Chevez dispised illegals, because he knew that they would undercut the workers here legally and damage gains the union had made. That's exactly what is happening.
The vast majority of illegals, especially in California, where illegals cost the state more than 20 billion dollars annually, do not work in agriculture. They work in restaurants, construction, hotels, landscaping, retail, manufacturing, in just about every conceivable entry-level position in the state... which means that legal residents and citizens no longer have those jobs available to them. California's young people are having more and more difficulty finding entry level jobs, which have been snapped up by illegals... because employers do not bother to check for stolen social security and green card numbers, since there is no significant chance of them ever being caught and fined.
Seriously, dude, you do not know what you are talking about.