EXTENDING THE USE OF CROP MODELS TO STUDY PEST DAMAGE

Most crop growth models do not account for damage caused by pests. Thi s limitation must be removed if the models are to provide useful predi ctions of production under real farm conditions. A generic framework w as developed to couple pest damage of various types into the PNUTGRO a nd SOYGRO models for peanut and soybean, respectively. Coupling points were identified in the models for applying damage to leaves, stems, r oots, pods, seeds, whole plants, and to the supply of assimilate. The resulting models were tested by simulating crops with measured pest da mage levels for peanut (foliar disease) and soybean (foliar feeding in sects) and comparing observed and simulated crop growth and yield resu lts. This approach for coupling pests with crop models has potential f or extending the practical applications of crop models to a broad rang e of problems.