Southeastern, PA. 30 miles west of Phila | Here is southeast PA I have quite a number of growers who routinely plant corn on corn. We usually assume a 10% yeidl drag in the 1st year of corn on corn. After that it normally levels off. Of course we always increase N rate by 30-50 units N.
We have always believed the primary reason for the yield drag is increased disease pressure and insect pressure (rootworm). But now that most growers are using RW corn and we still see the yield drag I believe it must all be coming from disease pressure.
I know it is not lacking in N because when we do a late season stalk nitrate test the test always comes back high.
We have been experimenting with fungicide applications for three years now. The only place that we can find a positive return on investment has been on hybrids with poor leaf disease ratings.
Here in Chester County we are in a no-fly zone and with all our contours and uneven terrain taking a hi-boy sprayer through tall corn is almost a joke!
So I guess in the end I need to come back to the idea that it is because of disease.
Merlin |
Corn on Corn vs. Corn on Bean Yields
