Early Vegetative Growth Simulation in a Common Bean R I L Population.

Knowledge of the phenological stages influencing common bean (Phaseolus vulgaris L.) growth and development is crucial to obtain reliable yield estimates and help optimizing management and production practices. This study aims to predict the growing rates and phenologic stages of 164 common bean recombinant inbred lines (RILs) and the parents (‘Negro Jamapa’ and ‘ICA-Calima’) at one of five locations (North Dakota, Florida, Puerto Rico and two in Colombia). Dry weight of the main stem (DWMS), the hypocotyl (DWH), and the primary leaves (DWU) from  2012 experiments in Prosper, ND were used to predict bean growth at early stage. Growth rates were determined by using the Blackman equation and thermal units were accumulated over the number of days for each stage taking into account mean and base (10^oC) temperatures. Predictions from these simulations at three different growing times were compared to the observed values. Evaluation by using the square root mean square error (RMSE) of the observed and predicted values indicates a good performance of the simulation model with values (0.1 to 0.2) approximating 0. The lowest number of thermal unit (TU) needed to reach emergence (VE) is 66 and 128 the highest values. First true leaves (V1) appear after a cumulative 173 to 240 TU. The evaluation indicates good predictions for early bean growth. These preliminary results will be useful in the near future and the data set can be adjusted and matched with QTL for developing a gene-based crop model including all locations. Contrasting interval time for phenologic stages at various locations can be a good evidence of genotype by environment interaction.

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