Optimization and Evaluation of a Bacterial Spot of Stone Fruit Disease Model in Chinese Peach Orchards

Controlling bacterial spot of stone fruit disease has been a key target in peach planting areas throughout the world. Accurate warning of the risks of infection is crucial for determining spraying time. A bacterial spot model applicable to peach planting areas in China has not yet been built. We optimized and evaluated a model developed for bacterial spot of stone fruit disease in Spain, adapting it for two cultivars and locations in China. Both the original and optimized models performed well in estimating the incidence of bacterial spot in both cultivars and two locations during the eight evaluated years, obtaining a correlation coefficient (R²) of 0.88, an average mean absolute error of 3.19, an average root mean square error of 3.34, and a slight overestimation (coefficient of residual mass = 0.098). Wetness duration and mean temperature during the period play significant roles in the model; a shorter wetness duration resulted in a lower incidence in Beijing in 2023 compared with other years. This study demonstrates that the model can be an effective tool for determining the warning of the incidence of bacterial spot of stone fruit disease and helping peach growers in China control this disease.