Cabbage Integrated Pest Management : An Ecological Guide.

Major Agronomic PracticesHow to treatThere are four main methods for seed treatment:1. Physical: by soaking seed in hot water.2. Chemical: by sterilizing seed with chemicals or by 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 (see also section 7.10).None of these treatments will completely prevent pathogen attack in all circumstances!In addition to seed treatment, it is important to select a field that is free of soil-borne diseases. Somemanagement practices for soil-borne diseases include crop rotation (using soil that has not been usedfor growing cabbage or other cruciferous crops for at least 2 years) and the use of resistant or tolerantcabbage varieties. See also sections 3.2 on variety selection, 3.4 on soil, 3.7 on nursery management,3.12 on crop rotation, and box in section 3.4.3.3.3.1 Hot water seed treatmentTo kill most spores or bacteria attached to or within the seed, seedshould be soaked in hot water at 50 o C for 30 minutes.The right water temperature and the right duration are very important. Ifthe water is too cold, the pathogens are not killed. If the water is too hot,seed germination will be strongly reduced.The easiest way to treat seed is to prepare water of 50 o C on a small fireor burner. Carefully check the water temperature with a thermometer.Poor the 50 o C water into a thermos flask and add the seed. It may beeasy to wrap the seed in a cloth to keep them together. Leave the seedin the flask for 30 minutes. After soaking in hot water, the seed is placedin clean, boiled, cold water to cool down. Dry by spreading the seed ina thin layer on paper or on cloth.In some cases, a fungicide coating is applied after hot-water treatment. See section 3.3.2 below.J Hot-water treatment is easier, cheaper and more effective than tryingto control seed-borne diseases in the field with chemicals. J3.3.2 Chemical seed treatmentMany seed companies use chemical treatments, such as sodium hypochlorite, to sterilize the surface ofthe seed. Next to this, seed can be coated with a fungicide. This fungicide can sometimes be seen onthe seed as a colored coating. The fungicide used will be listed on the seed package. The fungicide cankill spores of diseases that are present on the seed and during germination it gives some protection ofemerging roots to soil-borne diseases. Chemical fungicides for seed protection are relatively inexpensiveand cause little environmental damage since they are used in small amounts. However, they are effectiveonly for a short time (at most one month) and they do not spread through the soil with the root system.Cabbage Ecological Guide - 200014