Conditions under which seed must be treated

1) Injured Seeds: Any break in the seed coat of a seed affords an excellent opportunity for fungi to enter the seed and either kill it, or awaken the seedling that will be produced  from it.  Seeds suffer mechanical injury during combining and threshing operations, or from being dropped from excessive heights.  They may also be injured by weather or improper storage.

2) Diseased seed: Seed may be infected by disease organisms even at the time of harvest, or may become infected during processing, if processed on contaminated machinery or if stored in contaminated containers or warehouses.

3) Undesirable soil conditions: Seeds are sometimes planted under unfavourable soil conditions such as cold and damp soils, or extremely dry soils.  Such unfavourable soil conditions may be favourable to the growth and development of certain fungi spores enabling them to attack and damage the seeds.

4) Disease-free seed: Seeds are invariably infected, by disease organisms ranging from no economic consequence to severe economic consequences.  Seed treatment provides a good insurance against diseases, soil-borne organisms and thus affords protection to weak seeds enabling them to germinate and produce seedlings.

Precautions in Seed Treatment:

Most products used in the treatment of seeds are harmful to humans, but they can also be harmful to seeds.  Extreme care is required  to ensure that treated seed is never used as human or animal food.  To minimise this possibility, treated seed should be clearly labelled as being dangerous, if consumed.  The temptation to use unsold treated seed for human or animal feed can be avoided if care is taken to treat only the quantity for which sales are assured.

Care must also be taken to treat seed at the correct dosage rate; applying too much or too little material can be as damaging as never treating at all.  Seed with a very high moisture content is very susceptible to injury when treated with some of the concentrated liquid products.

If the seeds are to be treated with bacterial cultures also, the order in which seed treatments should be done shall be as follows

i) Chemical treatments

ii) Insecticide and fungicide treatments

iii) Special treatments