The October Crop Report estimated Iowa com and soybean yields at 135 and 44 bu/ac, respectively. One can expect these numbers to be adjusted somewhat by subsequent reports. The yield relationship between com and soybean varies between regions and is a reflection of the variation in growing season in the different parts of the state. Yield estimates, as of October 11, are presented by Crop Reporting District in Table 1. Yield variability is the result of many factors. The major negative factors in 1996 were too much rain, late planting, too little rain, cool conditions throughout the growing season, early frost, com borers, weeds, gray leaf spot, etc. The importance of each varied greatly depending on region of the state.