During long-term and short-term storage of seeds, the important internal factors that affect the lifespan of seeds are moisture content in them. Moreover, the external environment, the temperature, and relative humidity in the storage room also affect its storage.
Indeed, the relative humidity of the air surrounding the stored seeds plays a very important role. The reason is that the humidity level within the seed itself is affected by the relative humidity in the air, and the humidity inside the seed cell is affected by mold and pests.
◇ Moisture Content
Seeds Since the moisture content of seeds is the most important factor in seeds degradation. To store the seeds they should have adequate moisture and generally should not exceed 10% of the seed weight. The seed coat is so hydrophilic that even well-dried seeds absorb moisture from atmospheric water vapor. Therefore, even if you dry it properly before storage, exposure to high humidity, such as the rainy season, quickly absorbs moisture even when expose to high humidity, so exposure should be avoided as much as possible.
◇Moisture content in the storage environment
Seeds can absorb moisture even in the storage environment. Therefore, many facilities, including a dehumidifier or container desiccant, are required to completely remove moisture in the seed cellar. In places with no drying facility, humidity can be controlled using a sealed container with chemicals such as desiccant, and sometimes saturated salt solution or sulfuric acid is added.
A widely used seed drying agent is silica gel. When we treat Silica gel with cobalt chlorine it turns from blue to red when the relative humidity is over 45%.
For the solution, put about 1 kg of desiccant in a 10 kg container, and if the color of the desiccant does not change, the relative humidity in the container is within 45%. It maintains seed half-lives for several years. To buy moisture absorbers for shipping containers, click here.
Temperature is a very important factor in seed storage. Although the seed’s vigor gradually decreases even at low temperatures, in general, the vigor of the seeds decreases easily at high temperatures.
In terms of conservation of genetic resources is carried out under the freezing point temperature condition, but it is not used much in general horticultural seeds. According to the study, the potential lifespan is halved for every 5℃ increase in temperature between 0-50℃. And the lifespan of the seeds is reduced even for a very short period at high temperature. Therefore, it is better to store it at a lower temperature under the given conditions.
◇Seed treatment method during storage
When storing seeds, it is necessary to select the seeds to reduce the damage from pests and diseases. And pay attention to drying to reduce the moisture content in the seeds.
However, pests occur during storage for various reasons, and fumigants are mainly used to treat some drugs to control them. Fumigants come in solid, liquid, and gaseous states. Fumigants should be inexpensive, easy to evaporate, diffuse well, and non-combustible without affecting seed vigor. In particular, the risk to the human body should be lesser.