Temperature Effects Oo Adventitious Root Development in Blue Grama Seedlings

Abstract

Adventitious root initiation and development of six blue grama (Bouteloua gracilis (H.B.K.) Lag. ex Steud.) accessions were evaluated at seven temperatures in controlled environment conditions. During a 4-day growth performance test, individual growth responses of 21-day-old seedlings exhibited different temperature optima within the 5 to 35 degrees C temperature range. The largest number of adventitious roots, 3.8 per seedling, were initiated at 20 degrees C. Temperatures less than 15 degrees C probably would not be adequate for adventitious root establishment in the field. Precipitation probabilities and rates of adventitious root growth at constant temperatures suggest two possible alternatives for establishment of blue grama in the Central Plains: (1) plant in early May when temperatures for root growth are marginal, but probabilities of 2 or more consecutive wet days are relatively high; and (2) plant in mid-summer when temperatures are favorable for emergence and root growth, but probabilities of 2 or more consecutive wet days are very low. Modification of the micro-environment and development of improved seedlings will be needed before either of these alternatives provides a reliable method for blue grama establishment.