(IPPM) in Vegetables - Vegetableipmasia.org

Resource Manual on IPPM in Vegetable
World Education Philippines, Inc.
E. Seed Treatments
Two reasons to treat seeds
1. To control diseases attached to or inside the seed (seed-borne diseases),
2. To protect seeds against diseases in the soil that can attack seeds, emerging roots
or young seedlings (soil-borne diseases).
Seed-borne Diseases
Seed can become infected with fungal spores or bacteria (seed-borne diseases). Infection
can accur during the growing season, when seed is still on the plant or it may occur after
the seed has been extracted from the plant. Common seed-borne diseases of tomato are
early blight (Alternaria solani), Tobacco Mosaic Virus (TMV) and fungal wilt (Fusarium
and Verticulum).
Soil-borne Diseases
Seed can also become infected after it has been sown in the soil. Fungi or bacteria living
in the soil may attack the seed and cause death of the seed or the emerging roots even
before the seedling has emerged above the soil (soil-borne diseases). A common soilborne
disease affecting seed and seedlings is damping-off, caused by a complex of fungi.
When to Treat
When seed is bought from reliable seed companies, it will usually be disease-free. When
seed is locally produced, it is probably better to sterilize it before sowing. When soil has
causes problems with damping-off disease before, it can be helpful to coat seed before
sowing.
Seed Treatment Methods
There are four main methods for seed treatment:
1. Physical by soaking in hot water
2. Chemical by sterilizing seed with chemicals or coating seed with a layer of
fungicide.
3. Botanical by coating seed with a layer of plant extract.
4. Biological by coating seed with a layer of antagonistic fungi.
None of these treatments will completely prevent attack in all circumstances. In addition
to seed treatment, it is important to select a field that is free of soil-borne disease. Some
management practices for soil-borne diseases include crop rotation and the use of
resistant or tolerant varieties.
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