Seeing alot of tip back and short cobs but plants are green and 10 feet tall. We are in our 3rd dry year and wonder if we have tapped out all the subsoil. Last 2 years corn fired but still managed 18 to 20 round and 30 row length. This year not seeing as much firing but cobs are 18 and 20 round but only 20 long. something happened this year but I can't put my finger on what it was exactly.  One difference is I went from 32k pop to 34 pop would the 2k increase cause that much difference in row length?