High temps kill much of the pollen, and humidity clumps
the surviving bits. Fruit sets slow or stop when the
daily highs are consistently in the mid-90s.
A great tip to induce setting is to simply “flick” the
blossoms daily with you finger. A simple “finger flick”
or two will help stir up that pollen and greatly improve
fruit sets.
Brandywines and BW Sudduth strain(especially), are worth
the attempt and extra attention as they can be among the
best tasters out there.
JJ61
Every time I walk through the rows of tomatoes I give a nice flick or tap to the stems that have floweres on them.