Hyperspectral Evaluation of <i>Venturia inaequalis</i> Management Using the Disease Predictive Model RIMpro in the Northeastern U.S.

Use of hyperspectral spectroradiometers allows for information on different light bands to be captured, allowing for identification of plant health status. Apple scab is the most important disease in the production of apples. RIMpro is a web-based decision support system (DDS) for orchardists that has the capacity to improve optimal fungicide application for the control of apple scab and has the potential to reduce the number of applications and thereby reduce input expenses. The objective of this study was to complete a hyperspectral assessment of apple leaves in order to evaluate the spectral characteristics of trees sprayed according to forecasted infection events from the DDS. No significant differences in visual assessments or vegetation indices were observed between conventionally treated leaves and leaves treated according to the DSS. In the first year of this study two fungicide treatments were eliminated, in the second one fungicide treatment was eliminated. This finding is important because it provides evidence that plant health status is similar between conventionally sprayed trees and trees on a DSS-guided reduced spray program. In addition, the use of spectroradiometers for assessing the efficacy of different fungicide programs was demonstrated. Finally, potassium bicarbonate tank-mixed with sulfur was confirmed to be an effective spray material for managing apple scab. By integrating the precise information provided by DSSs and the use of biorational pesticides, agricultural producers, service providers and educators are able to adapt climate change considerations and action-oriented decisions into pest management plans.