Relationship between temperature and PAR on rate of strawberry fruit ripening

Strawberry growers require accurate forecasting models to predict harvest times and volumes; improved forecasting can lead to better pricing, more consistent fruit supplies and reduced revenue loss and waste. Prediction of fruit developmental rate is a vital component of an accurate strawberry crop forecasting model. In this study an experiment was conducted during the summer of 2020 in temperature-controlled glasshouses to model the effect of temperature and photosynthetically active radiation (PAR) on the rate of fruit ripening of two Everbearer strawberry cultivars. Plants of each cultivar were grown under a combination of six temperature (13, 16, 19, 22, 25 and 28°C) and four shade (0, 15, 30 and 50%) treatments. Individual flowers were tagged at opening and the number of days to berry maturity was recorded as well as the individual berry fresh weight, berry length, and diameter at the shoulder. Results showed a positive linear relationship between increased temperature and the rate of progress to fruit ripening. Rate of fruit development declined with increasing shade but the overall effect of PAR was small compared to that of temperature. A significant relationship between calculated berry volume and average berry weight was also found. The results are discussed in the context of improving strawberry forecasting models for strawberry growers.