Mature, strawhulled, awnless red rice(Oryza sativa) obtained from the South Farm, Rice Research Station, Crow ley, LA in 1985. Harvesting, processing, and storage procedures were those previously described(8). Air-dried seeds were stored at-15 C until use. Seeds were dehulled by hand just prior to treatments. Germination tests were conducted as described by Cohn and Hughes(10). Lots of 20 dehulled seeds were placed in 50 mL Erlenmeyer flasks containing 2 layers of Whatman No. 1 filter paper and 2 mL of test solution for 24 h. Dilute HCl or NaOH was used to adjust the pH of test solutions buffered with 25 mM citrate-phosphate buffer(pH 3-7) or 2-(N-cycloh- exylamino)ethanesulfonic acid(pH 9.3). The pH values uti- lized for weak acid treatments corresponded to their pK except for lactic and succinic acids(pH 3). Esters and alde- hydes were applied at pH 7 to minimize conversion to weak acids. Alcohols were incubated at the pK of the parent acid. The pH values of buffer controls corresponded to the pH used to evaluate each chemical. The medium pH of each flask was recorded after chemical incubation to confirm sufficient buff ering capacity. All incubations were conducted at 30 C in darkness. After treatment, seeds were rinsed from flasks, washed copiously with running water, briefly blotted with