The market adage that “big crops grow bigger” means that forecasts typically start out conservative, and a season that starts well typically ends well. The current betting is the opposite: small crops get smaller. The bears will recall that planting progress was unspectacular last year, and yet production surprised to the upside, mostly due to perfect weather. In 2009, the corn crop’s planting pace was 10 percent slower than the year before, but it produced yields that were 7 percent larger. A record 97 percent had been planted by week 20 in 2012 (see graph below), but drought caused the average yield to be substantially lower. All that said and ignoring total planted acres, the size of the corn crop correlates in most ye...