Storage, size and vigor of 'Esther' avocado seeds (Persea americana Mill.)

Avocado seeds present high size variability. Larger seeds, such those of the 'Esther' variety, are preferred when nurse seeds are used. Even though they are considered recalcitrant seeds, they are stored for propagation. The aim of this study was to evaluate the combined effect of three storage periods and three sizes of 'Esther' avocado seeds on vigor, in terms of electrolyte leakage, and seedling length and diameter. The experiment was conducted using a completely randomized factorial design. The factors were time in storage (10, 30 and 100 d at 5 degrees C and 80% relative humidity) and seed size (small, medium and large). Electrolyte leakage was evaluated as a measure of seed vigor, growth and later development of the seedlings. Seeds stored for 30 and 100 d showed the highest electrolyte leakage but produced seedlings with a larger stem diameter than 10-day-old seeds. The seeds stored for 100 d generated seedlings with stems three times wider than the seedlings stored for 10 d. The changes observed in electrical conductivity showed differences between the different sizes and storage times of seeds. It is concluded that storage time had a positive effect on the growth of 'Esther' avocado seedlings (length and diameter of the stem) regardless of the seed size. Electrolyte leakage was affected by seed age and seed size but did not correlate with subsequent seedling growth.