EFFECT OF POTASSIUM-NITRATE AND ETHEPHON ON FATE OF WILD OAT (AVENA-FATUA) SEED IN SOIL

A study under glasshouse conditions determined the effect of germination stimulants, potassium nitrate and ethephon, on emergence of several pure lines of wild oat from soil. Effect of the two chemicals on stimulating emergence was variable and no synergism noted when used together. Examination of exhumed seed showed that these treatments reduced seed viability. By counting the number of dead and adding to those that emerged, total seed removed from the soil was obtained. All treatments removed seed from the soil seedbank, especially when seed was old, near the soil surface, was primary seed, or from low or intermediate dormancy lines. However, because of the insensitivity of a large proportion of the seed and the high rates required it is unlikely that either potassium nitrate or ethephon has practical use for field application.