The influence of seed pre-treatments and soil conditions on the emergence of sesame seedlings

Abstract

Poor and uneven emergence of seedlings decreases the efficiency of sesame (Sesamum indicum) seed production. In a glasshouse study, seedling emergence was reduced by low soil moisture content (less than 20%, w/v) and by waterlogging (common in soils with small soil particles). Watering events that failed to raise soil moisture content above 20% caused most seeds to germinate (more than than 80%), but only some of these seeds emerged from the soil (less than 50%). Gibberellic acid pre-treatment of seeds (50 or 1000 mg/L) failed to improve emergence of seeds from soils with an initial soil moisture content less than 20%. This result supports previous reports suggesting that gibberellic acid treatment does not influence seedling emergence, and may only be useful to overcome seed dormancy in those sesame varieties where dormancy is a problem. For maximum emergence it is recommended that sesame seeds be sown in non-waterlogged soils and that soil moisture content be maintained above 20% for a number of days after sowing.