Let's see, you are planning on forming an LLC in California which means you'll be paying state's annual minimum franchise tax of $800, the farmers market will likely charge ~$200 for the right to sell there for the season, and you'll also need liability insurance for the market (I paid ~$200 a few years ago). So, with those three expenses you'll be starting off $1,200 in the hole before you've spent anything on actually producing or selling fruit.
Turning a profit on 50 fruit trees is going to be difficult.