It has been suggested that one bee per hundred flowers is an adequate pollination level. Seedless, triploid watermelons also require pollination. The pollination requirements vary greatly depending on variety and geographic area. Several hand harvests can occur during the growing season. The stigma is most receptive in early morning and several hundred pollen grains should reach the stigma for effective fruit set.
Male flowers outnumber female flowers.
The plants are mostly receptive in the morning, primarily before 9 a.m. Seed number and fruit weight increase in proportion to the amount of pollen transferred. Population levels are variable, but when these occur in large numbers, supplemental pollination by honey bees can be reduced. Growers should make every effort to conserve these bees by establishing sanctuaries to conserve nesting sites and food sources. Caged honey bee studies indicate hermaphroditic flowers are not capable of self-pollination. Flowers are receptive throughout the day.