Harvesting onions for dehydration in California starts in the Palo Verde and Imperial Valleys in May or June, proceeds north, and terminates in the Tule Lake area in October or November. Consequently, processing plants do not operate from November to May. To keep costs at a minimum, it is important not to prepare and staff the plants before the onions will be available to dehydrate. Thus, the problem is to predict far enough in advance the time onions will be available, so that employees and onions can arrive at the processing plant at the same time.

The authors would like to acknowledge the assistance of Rogers Brothers of California, Inc. in providing data.