Same here,, one or two crows,, the corn plants are pulled up, the little green growing stem is nipped of, and laying there,, the kernel is GONE !!
We found a pretty good solution,,
aluminum hanging from thin twine.,,
About 4 pieces for a 15X35 patch of corn,, no more crows.
We started with simply aluminum foil,, that did not last,,, but, a 9X13 disposable aluminum cake pan cut into 4 pieces,, does great.
The corner of the pan really dances to the slightest breeze. suspend the pan corner on about 6" of thin twine.
I even have a nut tied to the twine on a couple,, the nut will tap the pan,, crows are gone!!
They hate the reflection as the pan twists in the breeze.
They think it is someone looking at them.