Tuesday, November 14, 2006

Evaluating a Wheat Model for Simulating Growth, Development, and Yield of Winter Wheat in Southeastern USA.

Benjamin Wende1, Axel Garcia y Garcia2, Larry Guerra1, and Gerrit Hoogenboom3. (1) The Univ of Georgia, 1109 Experiment St, Dept of BAE, Griffin, GA 30223, (2) Univ of Georgia, 1109 Experiment St, Griffin, GA 30223, (3) Univ. Of Georgia, Dept Biology & Agricultural Engineering, 1109 Experiment St., Griffin, GA 30223-1797

Winter wheat (Triticum aestivum) is produced in many US states and it is an important component of farming systems. The objective of this study was to evaluate the performance of a wheat model for simulating growth, development, and yield of winter wheat grown in Southeast US. Seven winter wheat varieties from three maturity groups were planted in 2005 at Bledsoe Farm (Pike County, GA). The experiment was planted on November 03 in a randomized block design with 4 replications. To avoid water stress, irrigation was applied when necessary using a linear system. For each replication, dry matter of the plant and its components as well as leaf area and canopy height were obtained as well as the dry matter of the yield and yield components at harvest. In addition, the temporal variation of the soil moisture was recorded using a PR2, which uses electromagnetic signals to measure the permittivity of the soil (dominated by the water). Rainfall and irrigation were recorded with a rain gauge installed in the experimental area. The CSM-CERES-Wheat model, which is part of the Decision Support System for Agrotechnology Transfer (DSSAT v4.0), was used to simulate the winter wheat growth, development, and yield of the seven wheat varieties. Irrigation was necessary during the crop season. All varieties emerged by two weeks after planting. The longer the maturity group the higher the observed leaf area (LA) and total biomass. The model estimated adequately phenology and growth, as well as Leaf Area Index (LAI) for most of the varieties. Further studies will focus on the application of the model to support a web-based decision support system for long-term yield simulations in Southeast US.

Handout (.pdf format, 4966.0 kb)