Last year I grew one hill of Georgia Rattlesnake watermelon and got some pretty decent sized watermelons. However after the first one which was perfectly shaped, the ends of subsequent melons started getting more and more narrow. I called them pinheaded! The fat end tasted just fine while the narrow end looked rather undeveloped.
I can't find much information about this condition except one vague reference to a possible pollination problem but there were flowers growing nearby so there had to be pollinators around.
Anybody have any experience with this?