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Eye on Potatoes: Infrared photography no substitute for field scouting

While infrared aerial photography may be a useful tool
in crop diagnostics and management decisions, photos alone can’t
determine yield and quality, says Dr. Tom Gonsalves.

While infrared aerial photography may be a useful tool in crop diagnostics and management decisions, photos alone can’t determine yield and quality, says Dr. Tom Gonsalves.

“You have to combine the photography with field scouting for the best information,” the Manitoba Agricultural Food and Rural Initiative potato specialist explains.

Gonsalves’ department tested 15 Manitoba potato fields during the 2005 season using infrared aerial photography. Photos taken on July 31 of one field show a combination of red, black and green areas. Red indicates that the plants are in good health, Gonsalves explains, adding that the canopy was starting to mature.

In the green areas, there was some flowering going on. The tubers in this area were bigger but had knobs.

“That’s not what French fry processors want to see,” Gonsalves says.

In the black areas, he notes, the tubers were even knobbier.

Gonsalves and his team followed up the aerial view with a first hand visit to the field in mid-September. The red area had the highest yield, while the plants in the black area had an intermediate yield. The lowest yield was found in the green area.

While Gonsalves’ group has not worked with satellite photography, he notes that technology results in a better photo resolution than the infrared photos. Of course, as the resolution improves, so too does the cost of the procedure, he adds.

“It’s going to be expensive using infrared aerial photos for a small area,” he says. “The technology can be useful in assessing variations across a field; identifying areas that are adversely affected and how widespread the distribution is. You can’t see that from ground level.”