Comparing Yield Monitors with Weigh Wagons for On-farm Corn Hybrid Evaluation

For many years, on-farm yield evaluations of corn (Zea mays L.) hybrids were done with weigh wagons, handheld moisture testers, and measuring wheels. Today, most combines have continuous flow yield and moisture sensors. Published research results comparing the accuracy of combine-mounted sensor systems with that of weigh wagons are limited for on-farm corn hybrid evaluation. This study examined the accuracy of combine-mounted yield sensors with traditional weigh wagon methodology in on-farm corn hybrid strip trials. Data from combine-mounted sensors for plot weight, moisture percentage, and yield were compared with weigh wagon weight, handheld moisture testers, and calculated yield in six nonreplicated strip trials in 2012, 2013, and 2014 in east-central South Dakota. A total of 195 total entries were compared. Pearson correlation coefficients and linear regressions for weight, moisture percentage, and yield were calculated for each environment and for all environments combined. The Pearson correlation coefficients across all environments were 0.998 for weight of grain in pounds, 0.928 for grain moisture content percentage, and 0.983 for yield in bushels per acre corrected for moisture content. The probability of nonsignificance for weight, moisture percentage, and yield was P < 0.0001. Linear regression models predicting combine-mounted sensor of sample weight, sample moisture, and yield with the traditional system were significant at P < 0.0001 for all three measurements. Yield monitors can be used successfully for on-farm hybrid evaluations, replacing traditional methods that use weigh wagons, measuring wheels, and handheld moisture testers. METHODS USED TO COMPARE CORN VARIETIES AND HYBRIDS E corn performance has long been important, and methodologies used have changed over time. For centuries, seeds were handpicked based on appearance and kernels from the most attractive ears were planted the following year. As recently as the 1930s, open-pollinated corn was selected based on the appearance of the ears, with the biggest and best-looking ears saved to provide seed for planting the following year’s crop (Reinhart and Ganzel, 2003) (Fig. 1a). Published in Crop, Forage & Turfgrass Management DOI: 10.2134/cftm2015.0135 © 2015 American Society of Agronomy and Crop Science Society of America 5585 Guilford Rd., Madison, WI 53711 All rights reserved. Bjorn P. Nelson and Andrew W. Lenssen, Dep. of Agronomy, Iowa State Univ., Ames, IA 50011; Roger W. Elmore, Dep. of Agronomy and Horticulture, Univ. of Nebraska-Lincoln, Lincoln, NE 68583; formerly Dep. of Agronomy, Iowa State Univ., Ames, IA 50011. Received 27 Feb. 2015. Accepted 1 June 2015. *Corresponding author ([email protected]). Abbreviation: GPS, global positioning system. Published October 16, 2015