FACTORS AFFECTING THE VIABILITY AND GERMINATION BEHAVIOR OF CONIFEROUS SEED: PART I: CONE AND SEED MATURITY, TSUGA HETEROPHYLLA (RAFN.) SARG.

The following three papers show that both germination capacity and germination behavior are influenced markedly by maturity of cones and seed, and by various treatments, all of which can be controlled. Basic studies to discover the reasons for the radical changes in germination rate described herein are indicated.Commercial cone and seed processing often reduces germination capacity and increases the absolute or relative rate of germination. Dewinging, particularly if prolonged or if done in the presence of hard and sharp debris, has a marked effect upon both seed characteristics.High kiln temperatures (above 52 °C.), impact, and other "drastic" treatments reduce viability and increase germination rate. Seed that has been affected in these ways usually produces germinates whose radicles are discolored and subject to decay in the incubator. The seed itself tends to darken abnormally during stratification and/or incubation, and usually becomes contaminated quickly during incubation. Commercial seed that shows evidence of harmful treatment is usually dull and dusty and produces similar symptoms of weakness during incubation.