pollen

you need pollen to set fruit

and I was wondering how much heat can it take...
so I went looking and found this page

http://www.agry.purdue.edu/ext/corn/pubs/corn-07.htm
pollen dies off at about 100F 
and it makes sense about what I saw this year as far as the plants
they did not set much fruit at all, when the plants did set fruit, then it grew super well,
and now that it is cooling off it is producing a huge amount more.
so my findings of pollinating by hand in the morning was right on,
and the heat really does mess with things,
so I guess it is a good idea to put up shade cloth in the middle of the high heat,
looks like I can't breed my way out of this one. (but I will try for that limit anyway)
you just need the pollen to be living