Submitted to: Agronomy Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/15/2005
Publication Date: 12/28/2005
Citation: Martin, K.L., Hodgen, P.J., Freeman, K.W., Melchiori, R., Arnall, D.B., Teal, R.K., Mullen, R.W., Desta, K., Phillips, S.B., Solie, J.B., Stone, M.L., Caviglia, O., Solari, F., Bianchini, A., Francis, D.D., Schepers, J.S., Hatfield, J.L., Raun, W.R. 2005. Plant-to-plant variability in corn production. Agronomy Journal. 97:1603-1611. Interpretive Summary: Variation of crop yields has been reported across fields and the amount of variation may be quite large. As producers gather more data across their fields using yield monitors they are asking questions about the source of the variation and whether this can be reduced through improved management. This study was designed to evaluate the plant-to-plant variation across a range of environments in the United States and Argentina. Yield samples were obtained from fields by harvesting the individual grain yields from plants along a length of row. The amount of variation present within a short length of row was as large as that reported across the entire field. There was no difference in the amount of variation between fields that had low or high grain yields. The plant-to-plant variation present within a field provides an understanding of the amount of variation present and future studies can be directed to understanding the cause of these variability patterns. This information can help guide scientists in conducting studies across fields or landscapes in the amount of variation present and helps producers understand that variability exist within fields and is an inherent factor in all fields.
Technical Abstract: Corn grain yields are known to vary from plant to plant, but the extent of this variability across a range of environments has not been evaluated. This study was initiated to evaluate by-plant corn grain yield variability over a range of production environments and to establish the relationships between mean grain yield, standard deviation, coefficient of variation, and yield range. A total of forty-six 8 to 30-m corn rows (transects) were harvested by plant in Argentina, Mexico, Iowa, Nebraska, Ohio, Virginia, and Oklahoma from 2002 to 2004. By-plant corn grain yields were determined and the average plant-to-plant yields were calculated. Over all sites in all countries and states, plant-to-plant variation in corn grain yield averaged 2765 kg ha-1 (44.1 bu ac-1). At the sites with the highest average corn grain yield (11478 and 14383 kg ha-1, Parana Argentina, and Phillips, NE), average plant-to-plant variation in yield was 4211 kg ha-1 (67 bu ac-1) and 2926 kg ha-1 (47 bu ac-1), respectively. As average grain yields increased, so did the standard deviation of the yields obtained within each row. This indicates that by-plant variability can be expected in high and low yielding environments. Furthermore, the yield range (maximum corn grain yield minus the minimum corn grain yield per row) was found to increase with increasing yield level. This work shows that regardless of yield level, plant-to-plant variability in corn grain yield can be expected and averaged more than 2765 kg ha-1 over sites and years. Averaging yield over distances >0.5 m removed the extreme by-plant variability, thus, the scale for sensing and treating other factors affecting yield must be less than 0.5 m.