As we go into the last month of the 1997 growing season, many farmers are asking about the kind of season we have been having for corn. Right now the corn crop "looks" pretty good in the areas I have traveled. In general, precipitation has been good with some scattered dry areas in northwest and southeast Wisconsin. More than anything most areas need heat units. Growing Degree Unit (GDU) accumulation is starting to lag behind a typical year. Figure 1 shows GDU accumulation for 1997 and the 30-year average between 1961 and 1990 at Arlington, WI. For most of 1997, we have been below average. About 2400 GDU are required to achieve maturity for a 105 day RM hybrid. If we project GDU accumulation using 30-year average temperatures, we will not achieve 2400 GDU until the end of October; well past the average killing frost date of October 4. Figure 2 shows GDU accumulation for corn during 1988, 1992, 1993 and 1994 at Arlington, WI. For harvesting guidelines during "cool" seasons click here.