PREPARING SAGEBRUSH SEED FOR MARKET - EFFECTS OF DEBEARDER PROCESSING

Debearders are machines originally developed to remove grain from bear ded (awned) seed heads of small grains, They are now used in many type s of seed cleaning, including preparing sagebrush seed for market, Som e people have suggested that debearders may decrease sagebrush seed qu ality, We tested this hypothesis by using a debearder to process seeds of Wyoming big sagebrush (Artemisia tridentata Nutt, ssp, wyomingensi s) and measuring subsequent seed quality, Seed stalks were cut from 2 Wyoming locations, stored in an unheated warehouse, and then processed with a debearder for 2, 4, 6, 8, or 10 min, Seed germination and seed ling vigor were tested at 2-month intervals up to 16.5 months after pr ocessing, Temperature and relative humidity inside the debearder incre ased linearly from 14.0 to 22.4 degrees C and from 59.0 to 81.2% durin g the 10-min, processing time, However, the moisture content of seed m aterials did not change during this period, The number of undamaged se eds per gram of material did not change with processing and was simila r between collections. Stem length decreased with processing duration while percent of seed with pericarp removed increased, Germination per centage, time to 50% germination (T-50) and seedling vigor were simila r among treatments in both collections, Germination percentage increas ed in the first 4.5 months after processing and then remained at that level up to 16.5 months, Germination rate decreased (T-50 increased), but seedling vigor did not change with storage time, We recommend that seed dealers continue to use properly adjusted debearders to process sagebrush seed.