Parthenocarpy is a term in plant genetics for the formation of seedless fruits.
Parthenocarpic fruit is strange to see in nature, because it offers no obvious genetic advantage. The fruit forms without embryo or endosperm, rendering it incapable of any sort of procreation. Although this is often desired agriculturally for the purpose of consumption without the bother of removing seeds, there seems to be no real reason for a plant to create such fruit on its own.
Farmers are interested in developing parthenocopic fruit because it removes the concern of pollination. If the fruit develops without a seed, that means that not only will it be more appealing to most consumers, but also that the flower need not be pollinated to bear fruit.
In some plants, parthenocarpy can be advantageous in repelling pests from the seed-bearing fruits. Turnips produce ten or twenty percent parthenocarpic fruit in order to divert worms from feeding on the fruit with seeds. Certain worms evidently prefer the parthenocarpic fruit, and thus this becomes a logical course of action for the plant.