MEASURING POST-GERMINATION GROWTH

Measurement of heterotrophic plant growth is important for evaluating seed or seedling vigor. Hand measurement of large numbers of germinant s and seedlings is tedious, can injure young plants, and is often inex act when curved roots are involved. Using the Cobb-Jones germination m ethod with a digitizing tablet, a personal computer, apparatus, and me thods we developed, reduces the time, tedium, injury, and guesswork of ten associated with hand measurements. Evaluation of measurement preci sion using our methods indicates that repeated measurements of individ ual germinants/seedlings will have average differences that are less t han 1.0 mm.