Centre county Pennsylvania, USA | Martin, we find the Penn State charts reasonably accurate for the corn varieties we grow but we do our own calibration each year. To calibrate we simply use a high resolution digital scale to weigh a sample of randomly selected ears, then hand shell those ears and measure shelled grain moisture (adding 2% for combine shelling VS hand shelling) then weigh cobs and shelled grain separately and shrink grain to #2 corn. The rest is simple math.
We use that method when we estimate yields prior to harvest, 1st do the ear corn to #2 shelled corn calibration on a sample from the field, then use that calibration to estimate #2 shelled corn yield using ear weights from randomly selected ears in the field. After adjusting for 10% harvest loss, we find that reasonably accurate for estimating harvestable yields when corn moisture is below 32%. We haven't found a way to estimate harvest loss before actual harvest, yet..............
On-farm calibration seems to give better conversion from ear weight to #2 yellow corn than university charts do but we aren't sure it's worth the extra work. Being addicted to number crunching helps ;) |
Ear Corn
