Evaluation of apple flowering intensity using color image processing for tree specific chemical thinning

Chemical thinning in apple orchards is a commonly used technique for improving yield. The objective of this work was to quantify bloom intensity of individual trees using color images, and estimate the time for the peak of the bloom. Image acquisition campaigns were conducted in an apple orchard with Golden Delicious variety during two growing seasons. Image processing algorithms were developed to detect flowers. The correlation between the manual and automatic estimation of bloom intensity at the day of the peak was 0.90 and 0.97 for 2014 and 2015 respectively. Based on the above relationships, maps of blooming intensity were derived and its variability was established.