http://www.planthealth.info/diag_soygrowth.htm

 I would rather have my preventive treatment on at R1 but it is not too late to gain yield benefits.  We had lots of 8 and 9 bushel gains here last year but we live in Septoria Brown Spot Haven.  The average was 5.2 on about a hundred plots.  Corn and wheat were better, near 12 bushels.

I am planning to treat 100% of my crop with a replicated strips for testing.

Good luck on yours.

Ed