To improve reliability in predicting times and volumes of market arrival of major open-field vegetables, we used all available data to identify the Japanese production situation of such vegetables. First, based on market statistics, we investigated the assumption that the production allocation of major open-field vegetables is climatically optimized. Then, we prepared prediction models for cultivation periods, based on cultivation samples. We also elucidated the characteristics of cultivation methods, by region and season; and the ranges of preferred cultivation temperatures, by vegetable type and growing stage. In addition, by optimizing the allocation of major open-field vegetables for climate conditions (using deviations from the ranges of preferred cultivation temperatures as indicators), we identified the production situations for in-season major open-field vegetables, for 10-day periods, by former municipality (based on the Agriculture and Forestry Census), based on production and market statistics. The deviations were calculated by subtracting the limits of preferred cultivation temperature ranges from the meteorological environments of given cultivation periods (back-calculated from the arrival date based on market statistics and cultivation period prediction models). Based on a static optimization algorithm, optimized production situations were identified by repeatedly selecting, as optimal solutions, the allocations with the smallest margins, from all possible land resource allocations. Although there are still issues to be resolved, the identified production situations were consistent with the available data, and can be considered sufficiently valid.
