Effect of Moisture Content on seed preservation
Seed Storage is an essential step towards conserving plant genetic resources for the long term. Proper seed storage and maintenance retains its genetic integrity. Since very early days, several techniques were implemented to preserve seed viability in wild and domesticated resources. However, factors such as temperature, seed nature, relative humidity, moisture content, and so forth, led to a decline in seed longevity during storage. Seed moisture content is one of the mains reasons that affect the above case.
What should be the optimal seed moisture?
Moisture content in seeds greatly depends on factors like length and type of storage structure and packaging material. Up to 10% moisture is satisfactory for cereals stored in ordinary storage conditions for 12-18 months. For seed storage in sealed containers, they should be dried up to 5-8% depending upon the species.
What leads to excessive seed moisture?
When seeds do not get dried before storage, the high moisture content remains in them, leading to fungal growth and reduction in viability. However, sources say that seed moisture content below 4% may also lead to extreme desiccation or hard seediness in some crops.
Depending on the storage conditions and species, seeds can enhance their lifetime from a few years to centuries. Generally, seed storage takes place in cool and dry conditions. However, they tend to survive longer when stored in a wet and warm environment. The life of a seed mostly revolves around its moisture content. Therefore, it is necessary to dry seeds to safe moisture content.
How moisture content in seeds affect their preservation?
Low moisture plays a major role in affecting seed preservation than low temperatures. Seed germination capacity mainly depends on the duration, preservation methods, long term storage, and drying. Factors like a slight increase in moisture content and temperature may promote fungal growth and insect development in seeds. This further leads to the decline of seed germination capacity and the eventual death of seeds.
How can we retain seed viability?
For every 1% increase in seed moisture or ~5°C (10°F) temperature, the viability period decreases by half. To prevent that, they should be dried well and stored in controlled environments. Proper storage conditions effectively retain substantial viability in seeds over a considerable storage period. Dark places are the best for optimal seed storage. Although sunlight supports and stimulates the seed germination process, darkness helps keep the pre-germination processes in the seed at a low level.