Seed Treatment Methods

Seed Treatment Types

• Seed treatment is the process of applying a chemical or biological agent to a seed before sowing to protect it from diseases, pests, and other hazards.

Dust Treatment

• Seed is mixed with a dust fungicide until the seed is well coated, usually about 2 g of mercurials per kg seed is used.
• Handling hazards must be considered.

Slurry Treatment

• Seed is mixed with a dust fungicide in a special treater where small calibrated amounts of liquid (5–20 ml/kg grain or seed) are added, thus forming a soap-like slurry to ensure coating without undue wetting.

Wet Treatment

• Seed is mixed with a relatively small amount of concentrated liquid (about 100–300 ml/kg of seed).
• No recovery of liquid after treatment, but drying is necessary.

Quick Wet (Short Wet) Treatment

• Seed is mixed with a relatively small quantity of a concentrated, usually volatile liquid fungicide (about 20–40 ml/kg seed), ensuring good coating.
• Treated seed usually requires no drying, at least not when it is sown within a few days.

Oil Fungicide (Panogen) Treatment

• Seed is mixed with a slightly volatile mercurial germicide in an oily suspension in extremely small quantities (1–3 ml/kg seed).
• No subsequent drying is needed.
• Process is used also with slightly volatile pesticides other than panogen, e.g. chlorinated hydrocarbon insecticide.

Fumigation

• Seed is treated in an air-tight container or chamber for a definite period of time by the use of volatile material, a fungicide, nematicide, or insecticide.

Pelleting

• Application of a sticker prior to mixing the seed with dust which may contain pesticides, fertilizers, or other suitable materials.
• Seed is coated first with methacel, a cellulose acetate sticker in dilute solution and is then agitated with the dust in such a way that each seed becomes a pellet containing an outer zone of protectant.
• Sometimes, seed is treated with a fungicide before pelleting, such as sugar beet seed which is usually steeped in ethyl mercuric phosphate before the process.

Seed Treatment Equipments

• Basic principle in any chemical seed treatment is mixing seed and chemical in order to obtain adequate coating and for some treatments, adequate penetration.

The Shovel Method

• The simplest implement for treating seed is the shovel.
• Seed is piled on a floor, fungicide dust is scattered over the pile and mixed by portions until even coating of the seed appears to be obtained.
• Procedure may also be used with liquids as well.