CHEMICAL FREE SEED STORAGE

Seed storage simply means preserving the seeds for short term or long term period. In present context, Improper seed storage has led to decrease in the availability of quality seed due to the attack of fungus, pest and diseases. So, proper storage has been the main focus in seed security and self-sufficiency. The main purpose of proper seed storage is to protect the seed from fungus, pests and disease along with enhancing germination and supplying seed during the lean period. Seed storage can be carried out in various method using different materials:

Use of Ash

Seeds are filled in earthen pots to its 3/4 volume and rest 1/4 volumes filled by wood or cow dung ash. If grains are to be stored for a longer period, then after 6 months the grains and pots are sun-dried and again filled with fresh ash. 78.00 % of the farmers are following this method.

a. Farmer’s view: Wide range of storage pests are controlled for 6-10 months.
b. Scientific rationale

1. Ash contains silica which interferes with insect feeding and also hinders fungal pathogen multiplication.
2. Ash dust reduces the relative humidity of the storage condition and also dries the seed surface.
3. Egg laying and larval development of the storage pests could be hampered because ash dust covers the grain seeds.
4. Also affect the insect movement to search for mating partners and friction of the dust particles with the insect’s cuticle leads to desiccation and hampers the development of the pests.

c. Target crops: Pulses

Plastering of storage bins with clay and cow dung

Storage bins made of bamboo will be plastered with clay and cow dung which prevents insect attack from outside. 76.67 % of the farmers are following this method.

a. Farmer’s view: To reduce moisture content.
b. Scientific rationale:

1. Soil absorbs left out moisture in the seeds and grains and avoids spoilage.
2. Soil and cow dung paste acts as a barrier between seeds, grains and insects.
3. Cow dung acts as a repellent for storage insect pests.

c. Target crops: Pulses

Storage of pulses with common salt

Common table salt at about 200 grams of salt was mixed manually in one kg of pulse was followed to store pulses for a period of 6-8 months. 61.33 % of the farmers are following this method.

a. Farmer’s view: Insects are kept away from the stored grains.
b. Scientific rationale:

1. Salt has an abrasive action on the skin of insects thereby preventing their movement inside the storage containers and as a result their growth in the storage containers/bins/boxes is inhibited.
2. Salt has a hygroscopic and insecticidal property.
3. Salt helps in keeping the grain dry by absorbing the moisture thus avoiding spoilage and hence aid in safe storage .

c. Target crops: Red gram, Bengal gram, Black gram, Green gram and other pulses and legumes.

Turmeric application method

Turmeric powder is another good alternative method to prevent the grains from insects and pests. Grains and seeds are mixed with turmeric powder before storing them in containers or jute bags. This treatment provides protection for up to 6-8 months and is equally safe for consumption.50 % of the farmers are following this method.

a. Farmer’s view: Easy method and kills the storage pests.
b. Scientific rationale:

1. Turmerones and arturmerone are the components which act as insect repellent in turmeric. Its strong smell and insecticidal properties keep the insects away from food grains .

c. Target crops: Pulses and cereals

Use of Garlic cloves

Garlic cloves are kept in layers in the storage bins filled with seeds. Garlic cloves acts as a repellent for several pests.

a. Farmer’s view: Easily available and acts as a repellent.
b. Scientific rationale: diallyl di-sulphide, diallyl tri-sulphide and diallyl sulphide are the major compounds present in Garlic has anti-feedant, bactericidal, fungicidal, insecticidal, nematicidal and repellent properties.
c.Target crops: Pulses, Ragi, Paddy, Maize

Mixing of leaves

Leaves having insecticidal property like Neem/Margosa (Azadirchta indica), Nirgandi/Chinese chaste tree (Vitex nigundo), Madar/Calotropis etc., are collected and dried under shade till it becomes papery. These leaves are mixed with seeds and fill in the bags or storage bin.

a. Farmer’s view: Leaves are readily available at low cost and used for management of wide range of storage pests.
b. Scientific rationale: Leaves of Neem/Margosa(Azadirchta indica), Nirgandi/Chinese chaste tree Vitex nigundo, Madar/Calotropis etc., has very good insecticidal properties and also acts as antifeedents, repellents and growth inhibitors of storage pests.
c. Target crops: Pulses

Use of salt and chilli powder

250 grams common salt and 250 grams dry chilli powder are mixed with 20 kg seeds and filled it into a plastic bag or bin.

a. Farmer’s view: Insects are kept away from the stored grains and an easy method of storage
b. Scientific rationale: The pungent nature of chilli shows repellent effect on insects and salt has a hygroscopic and insecticidal property.
c. Target crops: Pulses

Use of Neem/Margosa leaves

Neem/Margosa leaves are collected from the trees and dried in shade and mixed with seeds/grains and stored in gunny bags or bins.

a. Farmer’s view: It is safe, cheap and effective method.
b. Scientific rationale:

1. Neem/Margosa contains bitter principles called meliacins like azardiracin, nimbin, salannin, meliantriol etc., and acts as anti-feedants against several pests.
2. The active ingredient azadirachtin, found in neem/Margosa leaves, acts as an insect repellent and insect feeding inhibitor and sterilant, antifungal and nontoxic qualities.

c. Target crops: Paddy, pulses ,Ragi

Use of Camphor

2 gram of camphor is placed per 5 kg of grain in the jute gunny bag which can be stored up to 3 months. After 3 months again the grains are sun dried and fresh camphor is kept in the bag. Camphor evaporates over time when stored. To prevent this, grains of pepper are placed along with camphor in the container.

a. Farmer’s view: Easy method to control storage pests.
b. Scientific rationale: Camphor inside the storage bag repels the pests due to the strong odour emanated from camphor.
c. Target crops: Cereals and pulses

Stored grain pests seriously damage food grains during storage. Several synthetic pesticides were used, but they have shown adverse effects on environment and persist for longer period in form of residues and entered in the food chain after utilization of products by organisms. Hence to replace these chemicals, safer eco-friendly and farmers friendly methods were evolved. Most of these practices are indigenous practices enhances utilisations of locally available materials.

Writer: Laxmi Bhandari (Student, Bsc Ag, IAAS, Paklihawa Rupandehi)