In the middle of June 2022, shipments of the main variety “Himekansen watermelons” reached its peak in Nishi Ward, Niigata City, one of the leading production areas of Small ball watermelons in Niigata Prefecture. It was warm in early spring this season, and there was a clear temperature difference between day and night.
The Akatsuka district in Nishi Ward, Niigata City, where watermelons are grown, is located along the Sea of Japan and is famous for being part of the Niigata Sand Dunes. The loose, well-drained soil seems to be well-suited for growing this excellent desert-indigenous crop. Not only does it grow vigorously, but it also occurs in watermelons grafted onto Phomopsis sclerotioides (generally white-flowered gourd). The tip of the vine wilts during the day and recovers in cloudy and rainy weather.The wilting spreads over the entire leaf before long, and it seems to tend to wither gradually. A part of the fine root turns brown and rots at first, but eventually it will rot. It seems that the taproot and branch roots are partially browned, fine roots fall off, and the amount of roots decreases. As the symptoms progress, the entire root becomes brown to blackish brown, and black striped lesions (pseudosclerotia) on the surface of the roots. I hear that if the fruit withers just before harvest, the fruits will not be fruitful and the sugar content will not rise, making it impossible to ship.
According to Niigata City, sand dune watermelon has a long history of cultivation, and it seems that it began with pillow-shaped watermelons planted in the mid-Meiji period. Around 1963, the planted area began to increase, and thanks to the dramatic progress in cultivation technology and the tireless efforts of producers, it seems that today it has been established as a production area that can be shipped early.