Site-Specific Topguard Application Based on Aerial Imagery for Effective Management of Cotton Root Rot

Cotton root rot is a century-old cotton disease that can be controlled with Topguard Fungicide recently. As this disease tends to occur in the same general areas within fields in recurring years, site-specific application of the fungicide only to the infected areas can be more effective and economical than uniform application. The objectives of this research were to demonstrate how site-specific fungicide application can be implemented using historical aerial imagery and variable rate technology. Procedures were developed for creating binary prescription maps from historical aerial imagery. Two different variable rate liquid control systems were adapted to two existing cotton planters, respectively, for site-specific fungicide application at planting. One system was used for site-specific Topguard application on two fields near Edroy, TX and the other on two fields near San Angelo, TX. Airborne multispectral imagery was taken during the growing seasons to monitor the performance of the site-specific treatments. Yield monitor data were collected from one field in each location. Preliminary results showed that the variable rate systems performed well and site-specific Topguard treatments effectively controlled cotton root rot. This research provides producers, crop consultants and extension personnel with useful information and assurance that site-specific Topguard application based on historical aerial imagery will be a cost-effective and environmentally-friendly approach to effective control of cotton root rot.