Method for using images from a color digital camera to estimate flower number

In many plants, flowering is conspicuous in the field, but enumerating flow ers is labor intensive, especially when flowers need to be counted on a dai ly basis. Frequent trips into plot areas and the physical contact with the plants can result in mechanical damage to plants, which can affect results. The objectives of this work were to develop methods using rotor digital im ages to estimate the numbers of flowers present in a scene captured in a di gital image and to do all of the processing in a fully automated mode that would allow the counting of flowers in large numbers of images. Images of l esquerella [Lesquerella fendleri (Gray) Wats.] flowers were made using a co lor digital camera of field plots during the 1996 to 1997 growing season. A n automated system to identify all of the pixels in an image that were flow ers and to count the number of flower spots in an image was developed. Proc essing time for individual images was 3.5 min compared with a minimum of 45 min for manual counts. The automated methods produced results that were hi ghly correlated with the number of flowers in an image as counted by hand. Results of the automated methods accurately tracked the temporal changes in flower number. Multiple counts of the same plants were made by the automat ed methods without damage to either plants that were counted or the plot. T his method has the potential to be used to predict harvest dates from peak flowering, to track the response of flowering to environmental renditions, and to evaluate the effects of cultural practices on flowering.