Wet Seed Treatments for the Control of Bacterial Fruit Blotch of Watermelon

The bacterium causing fruit blotch of watermelon was transmitted in seeds from fruit that had the typical water-soaking symptom; from fruit that had small, restricted, necrotic lesions; and from symptomless fruit adjacent to typically symptomatic fruit. Storage of seed at 12°C for 12 months did not reduce the level of seed transmission. Fermentation of seeds in watermelon juice and debris prior to washing and drying reduced the level of seed transmission from symptomatic fruit from 61% to less than 1%. Treatment of washed seeds from symptomatic fruit with 1% CaOCl 2 for 15 min was relatively ineffective in reducing seed transmission, but 1% HCI for 15 min was as effective as fermentation. Fermentation of seeds for 24 to 48 h followed by 1% HCI or 1% CaOCl 2 treatment for 15 min prior to washing and drying were the most effective treatments for eliminating bacterial contamination of watermelon seeds. These treatments did not adversely affect seed germination.