Harvest date prediction for field vegetables. A review

A review is presented of literature on harvest date prediction for major fi eld vegetables of North Western Europe. The most common approach used for h arvest date prediction is based on a relation of harvest date with accumula ted day-degrees, whether or not in combination with other factors. For the majority of crops no method for harvest date prediction is available. Indee d, many of them do not have a particularly critical harvest date and a numb er of them can be stored, which gives flexibility in:marketing. However, at least in the Netherlands, accurate prediction of when and how much of a fi eld vegetable product is ready for marketing is becoming increasingly Impor tant as marketing shifts from a supply-based to a demand-based system. It i s expected that systems will be developed whereby progressively more accura te estimates of the amount and quality of produce that will be ready for ma rketing on aspecific date will be provided to the marketing organisation by each individual producer, based on his planning and on field observations.