Hot water treatment of own seed to prevent seed borne diseases such as black rot, black leg, black spot and ring spot of crucifers is recommended. This treatment helps reduce the seed-borne pathogens such as Alternaria spp., Colletotrichum spp., Phoma spp., Septoria spp., and bacterial pathogens (Pseudomonas spp., and Xanthomonas spp). However, specified temperature and time interval must be strictly followed in order to maintain seed viability. Use a good thermometer or better ask for assistance from qualified personnel from your local extension office. To make sure that the seed is not damaged it is advisable to test the germination of 100 heat-treated and 100 untreated seeds.
For potato tubers heat treatment of 10 min in water at 55degrees Celsius should be used. The same treatment of naturally or artificially contaminated seed tubers will give a complete absence of blackleg infection in the field and decreased the amounts of powdery scab (Spongospora subterranea) and black scurf (Rhizoctonia solani) on progeny tubers.
Step 1 . In a large pot put plenty of water, heat the water to the required temperature.
Step 2 . Place seeds in loose cotton bag and submerge it in water. Follow strictly the recommended temperature and the time required. It is important that the water is maintained at a uniform temperature throughout the container. Constantly stir the water while soaking the bag. Suspend the bag and do not let it touch the bottom of the pot.
Step 3 . Remove the bag and cool it in clean cold water to stop the heating.
Step 4 . Spread the seeds on a clean dry paper to cool and dry.
Step 5 . Preferably do not store treated seeds. Sow them immediately on well-prepared seedbeds.