A controlled deterioration method for assessing the vigour of tomato seed lots

Controlled deterioration (CD) methods are used to assess the vigour of seed samples when shorter tests such as electro-conductivity or radicle emergence tests are not relevant. The aim of this study was to demonstrate that results from a controlled deterioration method developed for tomato are correlated with results from greenhouse emergence trials. To develop the CD method, two seed moisture contents (25 and 30% ± 0.5%) were compared over different durations (24, 48, 72 and 96 hours) at 47°C using four samples of tomato ( Solanum lycopersicum L.). A combination of time, temperature and seed moisture content was selected to maximise the germination capacity (GC) differences of these tomato seed samples and to assess vigour differences. Additional trials on six other samples established a significant relationship between one controlled deterioration combination and greenhouse emergence after 16 days ( r = 0.88 ) . In addition, a very good relationship was obtained with the selected CD method and the rate of usable tomato plants ( r = 0.95).