Using Multispectral Imagery to Monitor Cotton Root Rot Expansion within a Growing Season

Cotton root rot is a serious and destructive disease that affects cotton production in the southwestern and south central U.S. Accurate delineation of cotton root rot infestations is important for cost-effective management of the disease. The objective of this study was to use airborne multispectral imagery for detecting and monitoring the expansion of root rot infestations in cotton fields within a growing season. A number of cotton fields from near Corpus Christi and San Angelo in Texas were selected for this study. Airborne multispectral digital imagery with blue, green, red and near-infrared bands was taken from these fields three times during the growing season of 2010. The imagery for two fields from each of the two locations was georeferenced and then classified into healthy and root rot-infested areas using image classification techniques. The infested areas within each field were determined for each imaging date. Both airborne imagery and ground observations indicate that cotton root rot expanded at different rates over the season. The results from this study will be useful in understanding the progression of the disease and for the development of site-specific treatment plans for the disease.