Background An accidental damage occurred in a sugarbeet field in St. Thomas Township, North Dakota, during an aerial application of vine desiccant to an adjoining potato field. A 75-acre sugarbeet field falling in the west half of the SE of Section 11 160 53, North St. Thomas Township in Pembina County, was accidentally hit by the desiccant on the 25th August 2000. The situation was noticed on the 29th August during a routine inspection of the field.

A quick survey revealed that while there could be no disputing the source of the damage, the challenge would be to estimate the area and severity of the damage. A certified crop consultant was contacted who, after a preliminary review of the affected field, concluded that it will not be possible to accurately estimate the damaged acreage based on ground based surveys. The sugarbeets are extremely sensitive to the defoliant and the accident occurred at a critical growth stage of the plants. In order to amicably resolve the issue, a quick and reliable estimate of the damage and loss of sugar content had to be made.

 Use of Imagery Soon after the damage was noticed, multispectral data at two metersresolution was collected over the field using an airborne, digital camera to help assess the damage. Multispectral IKONOS satellite images at four-meter resolution, taken a few days before the accident, were used to assess the variations within the field before the damage occurred. Both aerial and IKONOS images were registered to the USGS digital orthoquads before demarcating the damaged areas.

 Economic and Social Benefits The damaged area was classified using ERDAS Imagine software and estimated at 18.3 acres. Ground samples taken at different time periods revealed that the average loss of sugar content in the damaged areas was 443 pounds per acre. At prevailing price of $0.20 per pound, the total loss was estimated at $1657. The study showed the usefulness of high-resolution imagery in accurate and timely assessment of loss due to an inadvertent chemical damage. The estimate based on remotely sensed data was a guiding factor in amicably settling the dispute between the farmer and the aerial sprayer, out of court.