Temperature profiles for germination of big sagebrush seeds from native stands.

Abstract

The germination of seeds of big sagebrush (Artemisia tridentata, Nutt.) from 5 locations on the margin of the Carson Desert, Nevada, was studied over 5 growing seasons. Temperature profiles for germination were developed for seeds collected from each location. The profile consisted of 55 constant or alternating temperatures from 0 through 40 degrees C. Seed quality was high with optimum germination, defined as germination not different from the maximum observed at the 0.01 level of probability, averaging 80% for all years and all locations. Differences in germination parameters existed among locations, but not within locations among years of production. Differences among years of production were most pronounced at extreme incubation temperatures. The most frequent temperature regime supporting optimum germination of big sagebrush seeds was 15/20 degrees C (15 degrees C for 16 hours and 20 degrees C for 8 hours in each 24-hour cycle).