Ground-Based Technologies for Cotton Root Rot Control

Phymatotrichum, or cotton root rot (CRR), is a fungus currently affecting broadleaf crops including cotton in the southwestern U.S. and northern Mexico.   The ability of CRR to lie dormant in the soil for several years tends to negate the effects of crop rotation, and it remains a problem for cotton because there are currently no genetically resistant cotton strains, and chemical solutions to date have not been cost-effective.  The overall goal of this research is to develop ground-based technologies for early detection and site-specific management of CRR.  Early detection could facilitate a more economical solution than those that might be used after plant infection had become more severe and widespread.  Three cotton fields were chosen for field data collection.  Freshly picked cotton leaves from healthy, disease-stressed, and dead plants were scanned with an ASD VisNIR spectroradiometer.  Surface soil moisture, temperature, and electrical conductivity were measured in each field with a Delta-T WET sensor.  A thermal infrared camera was used to capture leaf canopy images of healthy and disease-stressed plants.  A complete soil apparent electrical conductivity survey will be conducted for each field using an EM-38 sensor.  Plant status was visually inspected and recorded to form a series of disease progression maps in each field.  These data will be analyzed to (1) identify promising means for early detection of CRR, (2) relate disease occurrence to soil data, and (3) develop sound strategies for site-specific management of CRR.