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United States Department of Agriculture

Agricultural Research Service

Title: Modeling the Effects on Limited Water on Growth, Development and Yield of Field Crops: Can We Advance Our Modeling Approaches?

Authors
item Timlin, Dennis
item Fleisher, David
item Bunce, James
item Kim, Soo Hyung
item Anapalli, Saseendran - COLO STATE UNIV
item Quebedeaux, Bruno - UNIV OF MD
item Reddy, Vangimalla

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 2006
Publication Date: March 20, 2006
Citation: Timlin, D.J., Fleisher, D.H., Bunce, J.A., Kim, S., Anapalli, S., Quebedeaux, B., Reddy, V. 2006. Modeling the effects on limited water on growth, development and yield of field crops: Can we advance our modeling approaches? [abstract]. ASA-CSSA-SSSA Annual Meeting. CD-ROM.

Technical Abstract: One of the biggest problems in the simulation of plant processes is how to adequately and mechanistically describe a plant's response to water deficits. We know a great deal about the many individual processes that are affected by water stress but we still lack understanding about how these processes interact to affect whole plant processes, especially yield and development. Almost all models now simulate water stress through a phenomenological approach based on the effect of water stress, i.e., through reduction in carbon utilization and/or growth and yield. The most common method to simulate water stress in modeling is to use the relative transpiration ratio to quantify plant growth and carbon assimilation in direct proportion to the available soil water. This is an empirical approach that mimics the impact of water stress on growth and yield, but not the mechanism. This method also does not treat leaf expansion and carbon assimilation separately. We need a more physiologically based approach that takes into account processes that plants have developed to optimize carbon assimilation and minimize water loss under water deficit situations. Leaf expansion should also be separated from carbon assimilation. This research review addresses recent research that provides insight into how plants integrate their biological processes on a whole plant level to optimize carbon assimilation and growth under water deficit conditions while striving to avoid dessication. Different stomatal control mechanisms are discussed. These include control via soil potentials, and messages from roots, and control via leaf water potential. Methods that use some measure of soil water potential and leaf water potential appear promising when coupled with mechanistic photosynthesis models.

Last Modified: 12/20/2014
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