Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

___________________________________________________________________________________Major Agronomic Practices☺ Hot-water treatment is easier, cheaper and more effective than trying to controlseed-borne diseases in the field with chemicals.Solar seed treatmentAnother possibility for physical seed treatment is to sterilize seed in the sun. Put seed in a plastic bagand leave this in the sun for a few days (Kerruish, 1991).3.6.2 Chemical seed treatmentWhen seed infection is suspected, many seed companies usechemical treatments, such as sodium hypochlorite or sodiumphosphate, to sterilize the surface of the seed. Next to this, seedcan be coated with a fungicide. This fungicide can sometimes beseen on the seed as a colored coating. The fungicide used shouldbe listed on the seed package. The fungicide can kill spores ofdiseases that are present on the seed and during germination itgives some protection of emerging roots to soil-borne diseases.eggplant seedSeed coated with a fungicidelayer of fungicideChemical fungicides for seed protection are relatively inexpensive and cause little environmental damagesince they are used in small amounts. However, they are effective only for a short time (at most onemonth) and they do not spread through the soil with the root system.Use protective gloves when planting coated seed !3.6.3 Botanical seed treatmentSeed can be protected from some soil-borne fungi and from cutworms by a coating of abotanical extract such as crushed garlic. Garlic is well known for its strong odor whichhas a repellent effect on insects, or birds, and it can prevent diseases. See also section4.11.4 on botanicals. The garlic is thoroughly crushed to obtain juice and pulp. Seed ismixed with this extract. The seed can be immediately sown after this treatment, or leftto dry. No “scientific” data are available to compare this method with other seedtreatments but it is a common practice in some areas in Bangladesh (pers. comm. Prof.Ahmad, Plant Pathologist University of Mymensingh, Bangladesh, 1998).garlic3.6.4 Biological seed treatmentSeed can also be protected with a coating of biological agents. These are usually antagonistic fungi orbacteria that work against soil-borne pathogens. Examples of these antagonists are the fungusTrichoderma sp. and the bacterium Bacillus subtilis, which is sometimes mixed with a chemical fungicidefor commercial seed treatment. See “The Biopesticide Manual” (BCPC, U.K., Copping (editor), 1998) andinternet sites such as www14 and www15 (see reference list, chapter 11) for details on commerciallyavailable biocontrol products.The good thing about using biocontrol agents as seed treatment is that they also provide protection ofthe roots that emerge from the germinating seed. This is because the antagonists grow and multiply inthe area around the seedling roots. This way they suppress fungi that cause damping-off and rootdiseases.Biological seed protection agents are not yet widely available but research results are promising. Onecurrent problem is that biological agents applied to seed will not remain active during storage of seed(Harman, 1998).14Eggplant Ecological Guide