High-temperature drying increases longevity of rice seed

Studies have suggested that the drying conditions routinely used by genebanks may not be optimal for subsequent seed longevity. Whitehouse et al. compare the relative longevity of rice seeds in response to high-temperature drying in a flat-bed heated-air batch dryer (45 °C, 8 h d^–1) with the current practice recommended for genebanks of low-temperature, low-humidity drying (15 °C, 15 % relative humidity). They find that high-temperature drying improves longevity in seeds that are still metabolically active (>16.2 % moisture content) at harvest. Seeds that have already dried below this level at the time of harvest show no benefit of hot-air drying, but neither is it detrimental. They conclude that the genebank standards regarding seed drying prior to storage should be reconsidered to ensure maximum seed longevity.