Dr Bendangla Imsong & Dr Phool Kumari
Seed storage is the process of keeping seeds under controlled conditions to maintain their viability, germination capacity, and vigor until they are sown. Proper seed storage ensures that seeds remain healthy and capable of producing strong, productive plants when planted. The purposes of seed storage are to preserve the germination ability of seeds, to protect seeds from moisture, insects, fungi, and pests, to maintain seed quality over time and to ensure seeds are available for the next planting season. There are two types of seed storage: Short term storage with duration of few months upto 1 year and long term storage with duration of several years (under special conditions)
Factors Affecting Seed Storage:
1. Moisture Content: Seeds should be dried to a safe moisture level (usually 8-10% for most crops).
2. Temperature: Cool temperatures increase storage life. High temperatures reduce seed viability.
3. Humidity: Low humidity (preferably below 50%) prevents fungal and insect attack.
4. Containers: Airtight, moisture-proof containers like plastic bins, metal drums, or polylined bags are recommended.
5. Pest Protection: Seeds must be protected from storage pests like insects (especially bruchid beetles in pulses) and rodents.
Seed Storage of Pulse Crops:
Proper storage of pulse seeds (like pigeon pea, black gram, green gram, lentil, chickpea, etc.) is essential to maintain seed quality, germination, and prevent damage from pests, especially bruchid beetles (pulse beetles).
1. Selection of Seeds: Select only healthy, mature, disease-free, and well-cleaned seeds for storage and remove damaged, broken, or discolored seeds before storage.
2. Drying of Seeds: Seeds should be properly dried to safe moisture content before storage. The recommended moisture content is 8-10%. Sun drying for 2-3 days is recommended, but avoid over-drying or exposure to very high temperatures.
3. Storage Containers: Use airtight, moisture-proof, and pest-resistant containers such as Plastic bins, Metal drums, Polylined gunny bags, Double-layer polythene bags, Glass jars with tight lids, Cloth bags can be used for short-term storage with precautions
4. Storage Conditions: Store seeds in a cool, dry, and well-ventilated place. Keep seeds away from direct sunlight and damp areas. Maintain low humidity (preferably <50%) and cool temperatures to minimize insect and fungal activity.
5. Protection from Insects (Pulse Beetle Control): Pulse beetles (bruchids) are a major threat to stored pulse seeds.
Recommended methods for protection:
a) Seed Treatment before Storage:
• Mix edible oils (like neem oil, mustard oil, or castor oil) at 3-5 ml/kg of seed. This forms a coating that prevents insect infestation.
• Alternatively, use inert materials like ash or sand, thoroughly mixed with seeds, as a protective layer.
b) Botanical or Traditional Methods:
• Dry neem leaves can be mixed with the seeds.
• Use airtight containers along with neem leaves or oil treatment.
c) Chemical Control (Only for seeds NOT meant for sowing):
• For consumption stocks, insecticides like aluminum phosphide tablets can be used in storage rooms following safety guidelines. But do not treat seeds for sowing with harmful insecticides.
6. Storage Duration: With proper storage, pulse seeds can be stored for 6-8 months. However, for sowing purposes, avoid storing seeds for more than one year as viability decreases.
7. Periodic Checking: Inspect seeds at regular intervals for insect damage, fungal infection, moisture build-up and germination percentage (especially before sowing season)
Constraints in Storage of Pulse Crops:
Pulse faces several challenges during storage, which can lead to loss of seed quality, germination, and quantity. Here are the major constraints:
1. Insect Infestation: Pulse Beetles (Bruchids) are the most common and destructive pests in stored pulses. They lay eggs on seeds and larvae bore into the seed, causing damage. Even short-term storage is risky without proper protection.
2. High Moisture Content: If seeds are not properly dried (safe level is 8-10% moisture), it leads to fungal growth, seed rotting, reduced germination
3. Inadequate Storage Structures: Use of improper containers like gunny bags without lining or open storage increases moisture absorption, pest entry and seed deterioration
4. Temperature and Humidity Fluctuations: High humidity and temperature promote insect multiplication, fungal infection, loss of seed vigor and viability
5. Lack of Awareness and Training: Many farmers are unaware of correct drying methods, proper seed treatment and suitable storage containers which leads to avoidable storage losses
6. Limited Use of Safe Seed Treatment: Traditional or scientific seed treatments (like oil coating, neem leaves, etc.) are not widely adopted. Chemical options are limited, especially for seeds meant for sowing.
7. Rodent Damage: Improperly stored seeds are often attacked by rats, causing physical damage and contamination.
8. Economic Constraints Small and marginal farmers may lack access to improved storage containers (like metal bins or polylined bags), facilities for seed drying, knowledge of pest management during storage
9. Poor Market Storage Facilities: In some areas, bulk storage facilities for pulses are insufficient or unhygienic, leading to large-scale storage losses.
Seed storage is fundamental to ensuring a steady supply of superior seeds for future agricultural activities. Proper handling and storage maintain seed health, sprouting capacity, and quality until sowing, thus, following all essential steps is mandatory.
The writers are Dr Bendangla Imsong, CTO (Plant Breeding), KVK Dimapur, ICAR, Nagaland Centre and Dr Phool Kumari, Senior Scientist cum Head, KVK Dimapur, ICAR, Nagaland Centre
