Submitted to: Biotronics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2004
Publication Date: 2/15/2005
Citation: Pachepsky, L., Kaul, M., Walthall, C., Lydon, J., Kong, H., Daughtry, C., 2005. Soybean growth and development visualized with L-systems simulations: Effects of temperature. International Journal of Biotronics. 33:31-47. Interpretive Summary: User-friendly interfaces are prerequisite for acceptance of crop models. Currently, the outputs of most crop models are tables and 2-D graphs. However, most users make tactical management decisions from visual observations of plants. One way to translate modeling results into accessible information is to literally (3-D graphically) show a growing plant on a computer screen. The recent development of environmentally sensitive Lindenmayer systems(L-systems)models creates exciting prospects for visualization of crop modeling. However, there is a need to acquire data to construct L-system models precise enough for practical applications. Our objective was to evaluate the feasibility of developing an L-system model for soybean crops with simple resources typically available for agricultural research. We collected and used in an L-system model, growth and development data of two soybean cultivars grown in environmental chambers at three temperature regimes. The development of the L-system visualization model appeared feasible with this type of data. The introduction of L-systems to crop modeling is a viable and potentially beneficial development that can be used to further the use of crop models by producers. L-systems also presents an additional tool for validating crop models.
Technical Abstract: User-friendly interfaces are prerequisite for acceptance of crop models. Currently, the outputs of most crop models are tables and 2-D graphs. However, users make tactical management decisions from visual observations of plants. A 3-D presentation of crop growth may provide users with a more useful model output. An open parametric Lindenmayer Systems (L-systems) model was developed using data and the L-Studio L-systems software. Two distinct soybean (Glycine max L.) cultivars, (traditional Essex and newly developed Moon Cake) were grown from emergence to seed filling in controlled climate chambers at two temperature regimes, 26/21oC and 32/27oC (day/night) from April 1 through June 9, 2003. Detailed morphological observations and photographs were made weekly. Analysis of data showed that although both cultivars for both temperatures demonstrated very similar qualitative morphological characteristics, the quantitative difference was significant for both cultivars and temperature regimes. Basic morphological variables, i.e. plant height, number of nodes, internode length, and total leaf surface area were described by three- or four-parametric sigmoidal functions of time, or stage of development, with different parameters for each temperature and genotype. The L-systems virtual plants accurately simulated growth and development of these two soybean cultivars. The same L-systems model was used for all treatments; the effects of temperature and genotype were accounted for by L-systems parameters. A visual L-systems model of soybean can be used (a) for validating crop simulation models and (b) as a part of user interface, and may further the acceptance of crop model technology by producers.