Seminal and Adventitious Root Growth of Blue Grama Seedlings on the Central Plains

Blue grama has not established itself on abandoned farmland in the Central Plains. This study was conducted to determine the environmental conditions which limit the growth of the seminal and adventitious roots of blue grama seedlings in northeast Colorado. Field seedings of blue grama were made in both spring and late summer of 1973 and 1974. It was found that the soil surface had to remain moist for 2 to 4 days for blue grama seeds to germinate and initiate growth of the seminal root. A second moist period of 2 to 4 days was required some 2 to 8 weeks later in order for adventitious roots to initiate growth. If adventitious roots were not initiated, blue grama seedlings died during the winter. Seminal roots of blue grama grew 1 cm day-1 under favorable soil-moisture and temperature conditions, and only 0.6 cm day-1 under less favorable conditions. Adventitious roots grew 2.3 cm day-1 under favorable soil-moisture and temperature conditions, and only 0.7 cm day-1 under less favorable conditions.