Diseases and Management of Crops under Protected Cultivation

(Diseases and Management of Crops under Protected Cultivation)
Seed-borne diseases and Seed health: perspective
Role of seed sector in agriculture
As a consequence of increased product liability and competitive pressure with in the seed
industry, seed health has also become an important quality trait in market place. In industrialized
countries, the formal seed sector provides the vast majority of seed to farmers where the seed
health issues are well taken care of. Inspite of large investments in formal seed systems in
developing countries over the past 30 years, about 90–95%, of smallholder farmers' seed
demands are still met by informal sources at farm and community level.
Seed health in relation to crop production
The microorganisms associated with seeds can be overtly pathogenic, asymptomatic or
latent in seeds, and therefore if unsupported by a definite seed health test may cause a typical
disease syndrome or otherwise interfere to reduce final yield and quality of the produce.
Risk associated with import
Seed health testing helps in checking the transboundary introduction of alien species of
plant pathogens which once introduced may be devastating or are difficult to get rid off .
Seed health testing helps in anticipating the effective disease management choices and thus helps
in reducing the cost of production which otherwise would have been expensive. For healthy seed
production seed health certification program must go hand in hand with proper seed processing.
More-over seed health testing is one of the important tools for monitoring seed quality and
advisement for seed treatment.
Seed Health Testing
The demand and pressure for seed health testing is however increasing to deliver healthy
seed to farmers and seed producers. SPS (Sanitary and Phytosanitary) issues in WTO are
pressurizing the developing countries to give special attention to seed health testing and to respect
International Phytosanitary Regulations (IPR) issues.
Seed health management
Seed health management needs to be focused on:
• Estimation of losses attributed to seed-borne inoculum
• Predictive relationships between seed-borne inoculum and disease incidence
• Developing reliable, effective, cheap and rapid detection methods
• An understanding of pathogen tolerance in a seed lot before a technique is an
acceptable clinical seed health test.
• Establishment of seed health certification schemes
• Decisive proper seed processing and seed treatment
Advances in Seed Health Testing
The first International Rules for Seed health Testing was published by ISTA in 1928. This
document contained a special section on Sanitary Condition in which special attention was
recommended for Claviceps purpurea, Fusarium, Tilletia, and Ustilago hordei on cereals;
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