Development of mungbean model (MungGro) and its application for climate change impact analysis in Bangladesh

Mungbean (Vigna radiate L. Wilczek) is an important pulse crop for South Asian region. Its productivity is low and usually grown under water limited environments. Generally, irrigation at around flowering stage is provided if soil moisture is limiting. Its growth and yield is highly sensitive to fluctuations in climatic conditions, especially water-logging at any growth stage. Present study aimed at developing simple mungbean growth (MungGro) model, following the principles of SUCROS2 and the programme is written in Fortran Simulation Translator (FST). Water balance sub-routine has been undertaken along with G × E interaction, and the model was successfully calibrated and validated for growing environments of Bangladesh. Subsequently the model was utilized to evaluate the interaction effects of increased temperatures and carbon dioxide (CO2) levels. Yield, in general, decreased with the rise in temperature, primarily due to reduction in growth duration and seed weight growth rate of the crop. Increased CO2 levels compensated to some extent the deleterious effects of increased temperatures. Water-logging, especially at the beginning of the crop growth stage, had pronounced effect in reducing the grain yield drastically that was also reflected from the model. At present, we have calculated nitrogen (N) uptake and N fixation at the terminal stage of the crop. The model further needs to be improved by including N balance and insect-pest sub-routines.