Influence of chemical seed treatments on germination of dormant wild rice seeds.

Seeds of Zizania palustris which had been stored in water at 3 deg C for 120 days were soaked in 0, 28, 43, 57, 71, 86 and 95% ethanol for up to 24 h. Germination increased from 15% with no chemical treatment to 61% with a 7-h soaking in 43% ethanol. Seeds 1 wk after harvest were shaken in 95% ethanol for 15 s, then in chloroform for 1 min and again in 95% ethanol for 15 s and then stored in water at 3 deg . Germination at the end of storage for 60 days was 42% for treated and 16% for untreated seed. Freshly harvested seeds were scarified by tumbling with granite grit for 60 min and then placed for 24 h in all combinations of 0, 0.005, 0.05, 0.5 and 5.0 mM GA3 and 0, 0.063, 0.125, 0.25 and 0.5 mM BA. A combination of the highest conc. of both resulted in the highest germination after 21 days in water, 64% compared to 7% with no chemical treatment. However, seedling survival in the greenhouse 51 days after treatment was highest with the lowest GA3 conc. and the highest BA conc. Treating freshly harvested dehulled and scarified seed with 2.63% sodium hypochlorite for 2 h increased germination from 2 to 19% and seedling survival from 50 to 87% compared to no chemical treatment.