Effects of Processing on Germinative Capacity of Seed of Tall Oatgrass, Arrhenatherum Elatius (L.) Mert. and Koch

seed to remove appendages and thus facilitate seeding has been ported? By the expedient of hammering at controlled rates of speed and feeding, and by using the correct screen, it was found possible to obtain the required results with a miminum of injury to the seed. Such hammering and subsequent cleaning has become an accepted practice for processing many kinds of seed. Although seed processing has recognized advantages, there remains the possibility of an adverse effect on the germinative capacity of the seed. This effect could be evident either immediately or after warehouse storage. In some quarters there is reluctance to plant processed seed carried over for a single season. The species around which most co.ntroversy has centered is tall oatgrass. This article reports the results from numerous tests with processed and" stored tall oatgrass seed. Lots of tall oatgrass seed have been processed by the Pullman Nursery each year, beginning in 1939. Aliquot samples of one lot were taken for determinations of degree of de-awning and dehulling, injury to the caryopses, purity, and germination. The samples were stored in a dry, unheated room and tested for germination in subsequent years. The laboratory tests were made by Dwight D. Porsyth, Washington State College Seed Analyst. Germination tests were based on duplicate samples of ~oo seeds each, according to standard technics. The percentage of seed injured was determined by examination under a 2o X binocular microscope. The degree of treatment required to facilitate planting depends upon the nature of the planting and the species used. Tall oatgrass is usually milled twice. After the first run the awned fraction is removed by a scalper, remilled, and then both fractions recombined. Table i