The CIMMYT Wheat Atlas has been released as the public beta at http://wheatatlas.cimmyt.org

From the home page:

The Wheat Atlas is envisaged as a comprehensive electronic atlas containing relevant, readily accessible information related to wheat production, markets and research particularly in the developing world - essentially, a one-stop, fast access data resource for wheat scientists, policy makers and even business leaders. It is envisaged that the Wheat Atlas will be developed as a portal/CMS application, containing interlinked information at different geographical scales.

Currently the Wheat Atlas serves data for 15 major wheat producing countries in the world.