Sunflower is one of the most important crops in Argentina, which is the first world
exporting country of sunflower oil and meal.High yields of sunflower are attained when grain
filling coincides with high solar radiation, temperature and good hydric offer. In Buenos Aires
province, this could be attained by an early sowing date, but soil temperature would be lower than
those considered optimum for sunflower seed germination. The aim of the present work was to
evaluate vigour tests reliability to anticipate the behaviour of different sunflower seed lots to
unfavourable sowing temperature conditions. Seeds of three cultivars, with four different qualities
were submitted to the following vigour tests: cold in rolled towel with compost, cold in rolled
towel, methanol 20%, accelerated ageing with four and five days, conductivity of individual seed
exudate. Standard germination and field emergence in two sowing dates were also analysed. Data
were analysed by lineal generalised models and correlation. In almost all cases cold test with
compost and electric conductivity (vigour) anticipated seedling emergence in early sowings in the
region.