Traditional seed drying methods
Traditional seed drying methods practiced by farmers for ages have relied on ambient conditions or sun drying. Seeds are often dried partially in the field by cutting and windrowing plants before harvesting and either storing intact, as corn on the cobs, for example, or threshing the seeds before storage. For wet fleshy fruits like tomatoes or melons, the seeds are extracted and washed before drying. Seeds are then generally spread in the sun during the day and may be collected and covered during the night to prevent rehydration from dew. This procedure often needs to be repeated daily until the seed moisture content is reduced sufficiently for storage. While this system works well in sunny and dry climates, it cannot reduce seed moisture content to safe storage levels when the ambient humidity is high. At best, the seeds can only dry to the level in equilibrium with the ambient humidity.