As the hot, dry, record-breaking summer of 2012 concludes, it is obvious that the corn crop is maturing more quickly that normal. Many fields were off to a great early start, and the excessive heat, and heat unit accumulation, is driving the crop towards what is perhaps a very early harvest. Already one can see fields that are mature. Producers are talking about harvesting their earliest crop ever. Many are interested in estimating the yield of their fields, so as to aid in their harvest activities and also adjust their marketing plans.
There are two widely accepted methods for estimating yields prior to harvest. The Yield Component Method, developed at the University of Illinois (can be used relatively early in the kernel development process); and the Ear Weight Method (can only be used after black layer at physiological maturity). Both are reported to furnish yield estimates accurate to within 20 bpa of the actual achieved yield. Of the two, this author prefers the Yield Component Method, primarily because it can be used now, and has over years proven to be essentially equivalent to the Ear Weight Method.
LG Seeds Technical Bulletn #160 - Estimating Corn Yields - CLICK HERE