The latest National Agricultural Statistics Service (NASS) results are out for the citrus crop. These are results that are collected by the USDA to gauge production in the different growing areas of the country. From this most recent data, it is clear that citrus production is diminishing with time, most likely the effect of Huanglongbing. This is about a 60% decline from 2015.
The impact of this reduced production has reached out to not just growers, but also the juice industry they support, or are supported by. There's been a decline in the number of juice plants since 2014 which are reliant on volume to stay in business. If plants close, growers have fewer options for their juice citrus. http://www.theledger.com/news/20140705/at-least-one-juice-processor-expected-to-close
Most commercial crop production figures are collected by state and summarized on a state basis with the Agricultural Census every 10 years - https://www.agcensus.usda.gov/. The last was done in 2012.
Daily market prices for these different commodities can be seen on a wholesale basis by city, at USDA's Market News Service - https://www.marketnews.usda.gov/mnp/fv-home . This gives current prices and archived prices for products sold in different markets. It gives a general idea of what the grower will be paid for a given crop.
All of these sources are helpful for deciding where crop prices and markets are going. If you have time check them out.