A preponderance of parthenocarpic fruits is one of the outstanding features of this investigation. Out of approximately 3,000 crosses, 369 fruits were secured, over 99 percent of which were parthenocarpic.
A second significant fact is the pronounced manifestations of impotence of the species hybrids in cucurbits. Sexual derangement, especially of the staminate organs, was clearly evidenced. In a number of the crosses which resulted in fertile seeds, there were pronounced manifestations of physiological weakness. These symptoms of either impotence or physiological weakness characterize the crosses of C. pepo and C. maxima and of C. moschata and C. maxima and their reciprocals. On the other hand, back crosses resulted in fertile seed.
Erwin, A. T. and Haber, E. S.
"Species and varietal crosses in cucurbits,"
Bulletin: Vol. 22
, Article 1.
Available at: https://lib.dr.iastate.edu/bulletin/vol22/iss263/1