The latest news and trends on Mexican citrus can be found in this report from the U.S. Department of Agriculture's Foreign Agricultural Service.
Some excerpts on Persian limes, with quite a bit of background on costs....
Veracruz, the main Persian lime producing state, suffered dry weather conditions for most of 2010 as well as heavy rainfall from hurricanes that affected both the volume and the quality of the fruit. Lime production for MY 2008/09 was revised upward based on official data. High international market prices and fewer phytosanitary concerns have led to increased planted area for both Persian and Key limes. Approximately 42 percent of total planted area is devoted to Persian limes, 54 percent is for Key limes, and the remainder is for Italian lemons. The Persian lime area planted in Veracruz has grown at a faster rate than that of Key limes.
In fact, many producers have replaced orange and grapefruit groves with Persian limes in order to take advantage of strong international demand and higher prices. Michoacan and Colima are the main Key lime producing states. Key lime planted area has increased at slower rates due to domestic price swings. Michoacan has an excellent winter production window (December to February) that allows its Key limes to enter the domestic market first. As such, planted area has tended to expand more rapidly in this state.
According to producers, the domestic market is saturated with Key limes and a substantial increase in Michoacan’s planted area could reduce prices for Key limes in the international market. It has become current practice for Michoacan producers to suspend harvest during the course of the year to prevent oversupplying the domestic market and subsequent low prices. Therefore, planted area for MY 2010/11 is forecast to remain similar to that of MY 2009/10. Estimates for planted area for MY 2009/10 were revised upward and estimates for harvested area were revised downward from previous FAS Mexico estimates due to weather-related issues. Estimates for MY 2008/09 were updated according to official information.
The state of Colima lost planted area due to weather and high swings in lime prices. More than 25 percent of the Persian lime groves in Veracruz use micro-jet irrigation, or other irrigation systems, and produce year-round. Most of the irrigated Key lime groves are in the states of Michoacan and Colima and are able to produce year-round. In contrast, almost all of the planted area for Key limes in Guerrero and Oaxaca is rain fed. In Colima, about half of the Key lime groves have coconut palm trees planted between Key lime trees in order to increase producer revenue.