Development of a simple potato growth model for use in crop-pest management

Abstract A simple whole-plant level potato growth model was developed that accumulates and partitions dry matter into four state variables—leaves, stems, roots and tubers. Daily growth is computed from a function of the total solar radiation, the proportion of total radiation intercepted by the crop, temperature and soil water status. Dry matter is partitioned using modified Michaelis-Menten equations. At initialization, the seed piece size, plant and row spacing, and the values for the dry matter partitioning parameters are required. After initialization, the inputs required are the daily minimum and maximum temperatures and the daily soil water potential. Daily site-specific, seasonal radiation is presently estimated from a sine function. Model parameterization and output plotted against field data are presented for two cultivars, each planted a total of three times in two seasons. The model is intended for use in analyzing the dynamics of yield under variable pest pressures and environmental conditions. Model sensitivity, behavior and use in relation to modeling yield loss due to pests are discussed.