Submitted to: Agricultural and Forest Meteorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/30/2008
Publication Date: 3/27/2009
Publication URL: http://hdl.handle.net/10113/30030
Citation: Yang, Y., Timlin, D.J., Fleisher, D.H., Kim, S., Quebedeaux, B., Reddy, V. 2009. Simulating Leaf Area of Corn Plants at Contrasting Water Status. Agricultural and Forest Meteorology. 149:1161-1167. Interpretive Summary: Water is necessary for plant growth and development but is a limited and sometimes expensive resource. With the increases in the cost of energy required to pump and move water to desired locations, coupled with the decrease of available water for irrigation, it is essential to attain the maximum benefit from each unit quantity of water used for irrigation. When plants are under water stress, many physiological processes, including leaf expansion, are negatively affected. To study the effect of water stress on crop growth, and ultimately crop productivity, it is essential to understand the effect of water stress on the growth and final size of leaves which are at different water status. The functions developed in this study are able to simulate leaf expansion and final leaf size of corn plants which are irrigated with ample water, or are under minor or severe water stress. These functions provide us a way to better understand the effect of water stress on corn plant development and final output. With these functions, we will be able to predict the effects of different crop management scenarios or changes in climate on the productivity of corn, and therefore be able to better manage the irrigation of corn plants. The functions presented in this paper will help scientists who are also interested in crop modeling to more precisely simulate the effect of water stress on corn development and growth. It will also benefit farmers who need improved predictions on corn responses to changes in weather conditions and irrigation management scenarios.
Technical Abstract: An exponential decay function was fitted with literature data to describe the decrease in leaf expansion rate as leaf water potential decreases. The fitted function was then applied to modify an existing leaf area simulation module in a soil-plant-atmosphere continuum model in order to simulate leaf area of corn plants at different water status. Data were collected from field for two years as well as from sunlit growth chambers with different irrigation frequencies. Comparison among simulations and measurements indicated that the modified leaf area module improved leaf area simulation for plant under different water status. For plants under more severe drought stress, the improvement in leaf area simulation was more significant. These results suggested that the modified leaf area model presented an approach to mechanically link corn leaf area with corn plant water status, and was suitable for integration with existing corn models that simulate corn leaf area.