Abstract
Watermelon mosaic virus causes the most serious diseases of pumpkin plants in the Miyako and Yaeyama Islands. The pumpkins of infected plants showed the appearance of abnormal 'wens'. The symptoms of fruit were evident when leaf symptoms were observed at least on the first leaf to root side of fruit-bearing nodes and on subsequently emerging leaves. In order to harvest normal fruits, at least two symptom-free leaves to the tip side from fruit-bearing nodes had to be developed on the plants.
