Application of a dynamic growth simulation model to hydroponic production system for cut tulip

A previously developed dynamic growth simulation model for cut tulip produc tion in a plant factory system which predicts forcing period and flower qua lity of cut tulips from duration of bulb chilling and forcing temperature w as confirmed. In a 1993 - 1994 experiment in which bulbs were forced at 20 degreesC, irre spective of the duration of their chilling period at 2 degreesC, the simula ted values of number of days from planting to anthesis, shoot (cut flower) fresh weight, perianth length and dry weight of the component parts at anth esis correlated well with the observed values. In a 1998 - 1999 experiment in which the forcing temperature was lowered with the extension of the dura tion of bulb chilling at 2 degreesC, when the duration of bulb chilling was extended to 26 weeks or longer, shoot fresh weight, perianth length and dr y weights of shoot and floral organs at anthesis were underestimated by the model, while the dry weight of daughter bulbs was overestimated. These dif ferences were supposed to be caused by fluctuation in bulb properties and c ould be diminished by inputting the dry weights of the mother bulb and daug hter bulbs at planting into the model.