CUCHARV - A SIMULATION-MODEL FOR OPTIMIZING MECHANICAL HARVESTING RETURNS OF PICKLING CUCUMBERS

Three once-over mechanical harvesting systems for cucumbers grown in Michigan were compared using a discrete state simulation model. The model was constructed using parameters obtained in two separate sets of experiments that studied and determined plant fruit dynamics as a function of time and harvester parameters. The simulation used a computer algorithm called CUCHARV. Inputs to the model included crop maturity state, farm size, fruit pricing structure, and number and type of harvesters. A set of machine economic parameters was also input. This set was used to determine the cost of owning and operating the harvesting system using a built-in, cash flow subroutine. The model calculated daily net cash returns, based on the cash value per fruit size grade diminished by the cost of harvesting on that day. The output also included the daily average per hectare and daily total per farm of fruit number and fruit mass per grade and the average and total daily cost of harvesting. The model included a field trafficability subroutine to determine the sequence of go/no-go days on a daily basis for three locations in Michigan and for three soil types. Simulated and actual cucumber yield were compared in two case studies in Michigan revealing a future promise of the model to aid as a decision tool for farmers and processors.