The failure of a fruit tree to develop a normal amount of fruit may be due to a number of causes as stated by Kraus in volume VI of the Journal of Heredity. However, unless a plant develops fruit parthenocarpically, the development of fruit depends primarily upon how the pollen and pistil function relative to each other. As Kraus points out, fertilization by no means insures the development of a fruit, for very commonly the fruit does not develop despite the fact that normal fertilization occurred, but, on the other hand, in the absence of fertilization, fruit seldom develops among apples.
Proceedings of the Iowa Academy of Science
©1918 Iowa Academy of Science, Inc.
Martin, J. N. and Yocum, L. E.
"A Study of the Pollen and Pistils of Apples in Relation to the Germination of the Pollen,"
Proceedings of the Iowa Academy of Science, 25(1), 391-410.
Available at: https://scholarworks.uni.edu/pias/vol25/iss1/33