The boll weevil is one of the most destructive pests in American agriculture. A native of Mexico, it first appeared in Brownsville, Texas, around 1892. Since then weevil depredations to U.S. cotton crops have run into the billions of dollars. It was not until the recent decade that federal and state agencies and cotton growers combined forces and brought advanced technology to bear on the problem.

Texas was among the first to adapt geospatial technologies to the monitoring, decision-making and treatment processes involved in cotton production. The need was clear: Cotton is the state's number one cash crop, contributing over $1.3 billion annually to the Texas economy, even after losing 10 percent of crops to weevils each year. Losses would be upward of 20 percent had Texas, the federal government and cotton growers not taken action, according to Carl Anderson, agricultural economist and cotton marketing specialist at the Texas A&M Cooperative Extension Program.

In an effort to banish the weevil once and for all, the State Legislature in 1996 established the Texas Boll Weevil Eradication Foundation (TBWEF), a quasi-government entity funded by cotton growers, the state and the U.S. Department of Agriculture. Since 1999, the Legislature has appropriated $125 million in support of the foundation's eradication program.

Eradication Plans

At the time, TBWEF Program Director Osama El-Lissy, along with others, proposed using geospatial technologies in concert with proven labor-intensive monitoring and treatment methods as a practical approach to large-scale weevil eradication. El-Lissy said a combination of GIS, GPS and advanced database-management technologies could accelerate the foundation's eradication program.

"Based on GIS analysis of predefined biological, meteorological and operational parameters, such a system could indicate which fields to treat and when," El-Lissy said. "If the system is user friendly and practical to integrate into the Boll Weevil Eradication Program, fewer, less-experienced workers will be able to produce the same results as those achieved by many experienced personnel, but faster and more efficiently."

Role of Spatial Technology

In 1996, the TBWEF introduced the Boll Weevil Eradication Expert System (BWEES) to facilitate the eradication program. A GIS-based application developed by El-Lissy and the foundation's IT group, the BWEES incorporates data from a wide range of sources. Differential GPS point files of field coordinates, field shapes, acreage and weevil trap locations are downloaded to MapInfo Pro GIS and integrated into the base map of a cotton field and its surrounding environment. Grower data, planting dates, cotton variety, numbers of weevils found in the traps and related agricultural information are all stored in an Oracle database-management system and integrated into thematic maps of the respective cotton fields.

Trap data are collected with bar code scanners during weekly field inspections. The scanner automatically records date, time and trap number, and prompts the user for the number of weevils in the trap, the growth stage of the crop and related information. Data from the scanners is downloaded to the GIS and linked to the map location of each trap, enabling supervisors and producers to precisely locate weevil infestations in the field.

MapInfo MapX compares this data against parameters established for cotton fields at various stages of crop growth and infestation. Based on the number of weevils caught in traps over time, MapX color-codes fields meeting various growth and treatment criteria. Data on fields marked for treatment are entered into a contractor's DGPS-based flight-tracking system, which is designed to trigger spray only on the infested areas of the field. After treatment, the swath tracks and related data from the aerial applications are incorporated into the BWEES and used to assess the progress of eradication and monitor the health of the field.

The foundation has also Web-enabled the BWEES. Cotton producers can now query a TBWEF site to find out if weevils are present in their fields, where they were trapped, the degree of infestation and progress toward