An informal unit of volume used for berries in U.S. retail produce markets. Berries are typically stocked in corrugated cardboard trays holding six containers of one (dry) quart each, a total volume of about 6.6 liters
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}