Factors Influencing Dormancy of Peanut Seeds

Abstract

A study was made of the influence of seed coat, seed maturity, and various external factors on the dormancy of freshly harvested and stack-cured seeds of Virginia type peanuts. Among 19 varieties dormancy of fresh-dug seeds ranged from 6 to 84%. The optimum temperature for germination of stack-cured seeds with intact coats was in the range 22.5[degree]-30[degree]. Immediately after digging the optimum temperature for seeds with coats removed was 25[degree]. The later the digging date the less dormancy there was of seeds of apparently comparable maturity. In 2-seeded pods basal seeds were more dormant than apical seeds. Removal of the outer layer of the seed coat improved germination somewhat, but removal of the entire coat resulted in a still greater increase of germination. CO2 flowing at 14-28 liters/ minute through boxes containing imbibed seeds increased germination, but failed to induce germination of all seeds. Germination of basal seeds increased as the concentration of CO2 in air was increased from 1% to 10%; for apical seeds 1% was sufficient for maximum promotion. Ethylene (100 ppm) at 14-28 liters/minute induced complete germination of the more mature seeds with intact seed coats and promoted a high percentage of immature seeds with seed coats removed.