Effect of dry-heat treatment on bacterial fruit blotch and viability of watermelon seeds

Seeds of he diploid watermelon 'Mibao' infected with bacterial fruit blotch caused by Acidovorax citrulli, were dehydrated to 1-7% water content and dry-heated for 24-72 h at 70-80 degrees C. Following germination, seedlings were subjected to vigor tests and a bacterial fruit blotch-bearing test. Test results show that being dry-heated for 72 h at 75 degrees C is a safe and effective treatment for watermelon seeds. However; for treatment at 80 degrees C, seeds should have been previously dehydrated to a water content below 2%, in order to reduce negative effects on seeds.