Aerial remote sensing surveys of Fusarium wilt of cotton near El Paso, Texas

Authors: Yang, Chenghai; ISAKEIT, THOMAS - Texas A&M University; NICHOLS, ROBERT - Cotton, Inc

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 3/5/2019
Publication Date: 5/20/2019
Citation: Yang, C., Isakeit, T., Nichols, R. 2019. Aerial remote sensing surveys of Fusarium wilt of cotton near El Paso, Texas. National Cotton Council Beltwide Cotton Conference. pp. 246-249.

Interpretive Summary: Fusarium wilt of cotton, caused by the fungus Fusarium oxysporum f. sp. vasinfectum (FOV), is a widespread cotton disease in nearly all cotton production areas of the world. In 2017, the highly destructive FOV race 4 (FOV4) was confirmed in the Texas-New Mexico border area near El Paso, Texas. Two remote sensing aerial surveys were conducted in 2017 and 2018 to map the distribution and severity of the disease in the area and to assess the possible progression of the disease across the years. Aerial images were acquired from three apparently infested areas covering approximately 40,000 acres of land near El Paso. FOV4-infested areas within fields that had been confirmed by ground observations could be detected from the images. The consistency and change of the infested areas within fields could also be detected from the images over the two years. The images and preliminary results from the aerial surveys can be used in conjunction with ground verification for fast and effective identification of FOV4 infestations in the New Mexico-Texas border area.

Technical Abstract: Fusarium wilt of cotton is a widespread cotton disease that occurs in nearly all cotton production areas of the world. This disease is caused by the fungus Fusarium oxysporum f. sp. vasinfectum (FOV), which has many races or genotypes. The highly virulent FOV race 4 (FOV4) was found in the San Joaquin Valley of California in early 2001 and in the Texas-New Mexico border area near El Paso, Texas in 2017. A remote sensing aerial survey was performed in 2017 and a second one was conducted on September 19, 2018, about one year apart from the first survey. The intent of the surveys was to map the distribution and severity of this introduced disease in the area and to assess the progression of the disease across years. An aircraft equipped with multispectral and hyperspectral imaging systems was flown at approximately 5000 ft above ground level over three suspected areas: a 3800-acre area to the northwest of El Paso, Texas and a large 39,000-acre area and a small area of 2500 acres to the southeast of El Paso. Over 600 pairs of normal color and near-infrared images were acquired from the three areas, and the multispectral images for each of the areas were mosaicked to create orthomosaics. Images from portions of FOV4-infested fields were used to illustrate the spatial and spectral characteristics of FOV4-infested areas as compared to root-knot nematode infestations and soil variability. Plants infected early in the season were dead as evidenced by bare soil exposure. The images are being visually examined to identify probable FOV4-infested fields for ground confirmation. These aerial surveys provide useful information for faster and more effective identification of FOV4 infestations in the Texas-New Mexico border area. Multiple aerial surveys should be conducted during the growing season to monitor the progression of the disease in conjunction with ground truthing. Meanwhile, more research is needed to evaluate multispectral and hyperspectral imagery for identifying FOV4 from other coexisting races and stresses.