Ground-Based Technologies for Cotton Root Rot Control: Results From a Three Year Experiment

The overall goal of this research is to develop ground-based technologies for disease detection and mapping which allow for site-specific management of CRR (cotton root rot).  Accurately mapping CRR could facilitate a much more economical solution than treating entire fields. Three cotton fields around CRR-prone areas of Texas have been the sites for three years of data collection. Freshly picked cotton leaves from healthy, disease-stressed, and dying or dead plants were scanned with an ASD VisNIR spectroradiometer. Within each plot, moisture, temperature, and bulk electrical conductivity of surface soil were measured with a Delta-T WET sensor, or moisture only with a Theta Probe. A thermal infrared camera was used to capture leaf canopy images of healthy and disease-stressed plants. A complete soil ECa (apparent electrical conductivity) survey was conducted for each field with an EM-38 sensor. Plant status was visually inspected and recorded to form a series of disease-progression maps in each field. Leaf spectra have been evaluated with LDA (linear discriminant analysis) as well as wavelet analysis to relate them to classifications of infection level. Multiple linear regression was used to relate physical and chemical soil properties to the ECa values obtained from the EM-38. Disease-progression maps were examined with spatial statistics to describe the amount and variability of disease present in a given data set. These data continue to be analyzed to (1) identify promising means for detection and mapping of CRR, (2) relate disease occurrence to soil data, and (3) develop sound strategies for site-specific management of CRR.