Crop Quest is an employee-owned company dedicated to providing the highest quality agricultural services for each customer. The quest ofour network of professionals is to practice integrity and innovation to ensure our services are economically and environmentally sound. Official Publication of Crop Quest Agronomic Services, Inc. Newsletter published monthly by Crop Quest, Inc. • Volume No. 11, Issue No. 8, August, 2002 MISSION STATEMENT PERSPECTIVES By Ron O’Hanlon, president Drought conditions are having a significant effect on many of the crops across the High Plains, especially the western portions of the High Plains. According to the National Weather Service in Dodge City, Kansas, June through May of this year was the second driest on record, receiving only 43 percent of the average precipitation for this time period. Only June to May during 1952 and 1953 was drier, with a negative 13.77-inch deficit. Along the same lines, this season has also been very windy, with an average wind speed of 16.3 miles per hour during May and June. This ranks as the third windiest May/June period in the last 32 years for which data was kept. What effect can we anticipate if the corn crop is suffering from drought stress? Most fields throughout the western High Plains went into the spring planting season with inadequate subsoil moisture. The drought conditions have also magnified the effect various stresses a crop may experience during the growing season, such as hardpans, rootworm larva feeding and soil crusting. Studies summarized by Robert L. Shaw, Iowa State Univer- sity Department of Climatology and Meteorology, found a three percent reduction in yield per day of stress early in the growth period. However, yield losses jumped to eight percent per day of stress during the time of silking, and continued forabout two weeks thereafter, when exposed to drought. Pollination is a critical time period for corn development and yield. Silks grow about one to 1.5 inches per day and will continue to elongate until fertilized. However, temperatures greater than 95 degrees Fahrenheit with low relative humidity will desiccate exposed silks, but have little effect on the silkelongation rate. Heat has an effect on the pollen, which can be killed by temperatures in the mid-90s or greater when accompanied with low relative humidity. It is fortunate that most pollination occurs early to mid-morning when temperatures are lower. Effects of drought continue to increase in severity (Continued on Page 3) Fig. 1. Drought stress can reduce the number of kernels set by the corn crop and the degree of kernel fill. Fig. 2. Many corn fields will suffer lower yields based on the condition of the crop at the time of pollination.
