Quantifying the impact of frost damage during flowering on apple yield in Shaanxi province, China

Frost damage during flowering is recognized as one of the most serious agro-meteorological disasters affecting apple production in Shaanxi province, a typical apple producing area in China. Quantitative assessments of flowering frost damage to apple yield are critical for the development of strategies on mitigating yield losses, but have been rarely conducted. For the first time, our study used the process-based STICS model and statistical methods based on Lagrange interpolation method to assess the impacts of frost damage during flowering on apple yield at five study sites over the past three decades. Four canopy temperature thresholds were set as 0 °C, − 2 °C, − 5 °C, and − 35 °C for 0, 10%, 90%, and 100% frost damage on fruit number, respectively. The study results showed that STICS could effectively simulate the phenology and yield of apple, with the simulation errors less than 15%. Simulated yield losses caused by frost damage during flowering by STICS model were consistent with that estimated by statistical methods. Average yield loss due to frost damage during flowering estimated by STICS model was 6.35–29.27% in frost years during past three decades at five study sites. In general, both the frost occurrence days and intensities were the highest in the recent ten years. Our study provides a method to quantitatively assess the impacts of frost damage during flowering on apple yield for the prevention and mitigation of frost disasters in apple production.