NDVI to Detect Sugarcane Aphid Injury to Grain Sorghum

Area of Science:

• Agricultural Science
• Remote Sensing
• Entomology

Background:

• Sugarcane aphid (Melanaphis sacchari) poses a significant threat to sorghum production.
• Early detection of pest infestation is crucial for effective crop management and yield protection.

Purpose of the Study:

• To evaluate the efficacy of multispectral remote sensing for detecting sugarcane aphid injury in grain sorghum fields.
• To determine the relationship between spectral indices and the level of aphid infestation and plant growth stage.

Main Methods:

• Conducted a study in 26 commercial grain sorghum fields in the Texas Gulf Coast region.
• Collected multispectral imagery from a fixed-wing aircraft.
• Assessed plant injury ratings and growth stages, and calculated the Normalized Difference Vegetation Index (NDVI).

Main Results:

• A significant negative correlation was found between NDVI and sugarcane aphid injury rating.
• NDVI also showed a negative correlation with plant growth stage, indicating reduced photosynthetic activity in mature plants.
• Partial correlation analysis confirmed that NDVI is sensitive to aphid injury, independent of plant growth stage.

Conclusions:

• Multispectral remote sensing is a viable tool for detecting sugarcane aphid damage in sorghum.
• This technology can provide rapid and cost-effective pest status assessments for sorghum fields.
• Airborne multispectral imaging systems can identify stress in sorghum plants caused by sugarcane aphid infestation.