Below is a link to the Nov. 2012 UCCE San Joaquin County newsletter Field Notes. Page 8 has an article by Mick Canevari (Emeritus Farm Advisor) and Brent Holtz (Farm Advisor, County Director) on dormant weed control in tree nut crops.
http://cesanjoaquin.ucanr.edu/newsletters/Field_Notes_Newsletter44986.pdf