Non-Peer ReviewedSeed dormancy in annual canarygrass may lead to unsatisfactory germination in seed tests. The objectives of this study were (i) to quantify the levels of seed dormancy in three morphologically diverse annual canarygrass cultivars (‘Keet’, ‘CDC Maria’, & ‘CY 184’) relative to spring wheat & (ii) to determine the effectiveness of three treatments (GA3, KNO3, & chilling) & two temperature regimes (15/25°C & 15°C) in promoting germination of dormant annual canarygrass seeds. The hard red spring wheat cultivar ‘Katepwa’ control was included as a representative of a cereal crop that has been extensively characterized with regards to seed dormancy. In 1998 & 1999, the four cultivars were grown at Saskatoon, Canada. At maturity, panicles & spikes were hand harvested & stored at –20°C. Four replications of 50 seeds per cultivar were used in each experiment. Three experiments were conducted: (i) seeds were germinated at 10, 15, 20, & 25°C for one week, (ii) seeds were stored at 24°C for zero to eight weeks prior to germination at 22°C for one week, & (iii) seeds were treated with GA3, KNO3, & chilling prior to germination at 15/25°C (16/8h) or 15°C for two weeks. For experiment one & three, a split-plot analysis was used to analyze arc sin transformed percentage germination data. Average percentage germination data in experiment two were tested to be significantly different from 98% germination (P=0.05) based on one-tailed t-tests. Annual canarygrass developed deeper dormancy than the wheat cultivar in both years, particularly when germinated at 20 & 25°C. The highest percentage germination was observed at 15°C. Two (1998) & four weeks (1999) of storage at 24°C were required to overcome dormancy in annual canarygrass. Pre-chilling or KNO3 treatment prior to germination at 15/25°C (16/8h in darkness) resulted in average germination levels of 94% (1998) & 66% (1999). Potassium nitrate treatment prior to incubation at 15°C in darkness was the most effective method of promoting germination in dormant seeds, resulting in 99% (1998) & 97%
(1999) germination. Thus, we recommend the use of the latter method, instead of the former or currently recommended method (pre-chilling or KNO3 treatment prior to germination at 15/25°C [16/8h] in darkness), for testing germination levels of dormant seed of annual canarygrass
