The blooming male flowers were irradiated with 800 Gy soft-X-ray
and immediately used to pollinate each watermelon plant.
Unirradiated
pollen was used as the control.
Treatments were performed between 20 February and 1 March in ‘Fujihikari TR’, and in ‘Benikodama’, treatments were done between 18 and 29 March.
One week after treatment, fruit set was recorded.
Mature fruits were harvested at about 36 days in ‘Benikodama’ 36 and 48 days after pollination in ‘Fujihikari TR’.
Methods of cultivation and pollination were the same as in 1997.