Abstract
The development rate (DVR) and average temperature using cultivation data of Eustoma variety ‘Celebrity Rich White’ were calculated in Tsukuba City, Ibaraki Prefecture for the purpose of predicting the harvest date and developing technology to realize it. The relationship between the two was examined. A simple linear model was applicable to the average temperature and DVR from the start of raising seedlings to flower budding, and from flower budding to harvest. From the coefficients of the equation, the basal temperature (Tb) and thermal time (TT) were obtained as growth model parameters. The predicted date of harvest from flower budding showed high accuracy with an error of RMSE 3.1 days within 5 days with respect to the measured value. From these facts, it was considered that the harvest date can be predicted with high accuracy using the obtained parameters as the starting point of flower budding. In a greenhouse for commercial production, a cultivation test was conducted using the developmental parameters and device AMTeC, which actively controls the average temperature, with December 13 as the control starting point and March 10 as the target harvesting date. It was estimated that the average bud date of the study area was December 25, and the average harvest date was March 14. From these facts, it was demonstrated that the harvest date can be predicted using the developmental parameters starting from the flower budding date, and that planned production within ±7 days is possible by controlling the temperature.
