Condition 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 weaken 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 fungal 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.