You say tomato, they say tomography.

You say tomato, they say tomography

Researchers at the Georgia Experiment Station in Griffin are using a novel technique for performing agricultural research. They are experimenting with the use of computer-assisted tomography, or CAT scan, to look at everything from root-mass growth to apple bruises. Their work represents the first time a CAT scanner--designed to perform detailed X-ray analysis of the human body--has been completely dedicated to agricultural research.

"We first used the CAT scanner at Emory University in Atlanta about three years ago,' Brahm Verma, one of the researchers, told SCIENCE NEWS. "At first they were quite skeptical, naturally. Their primary perception was that we were probably going to mess up their machine.'

But early success in imaging such things as root systems, plant pest distributions and water absorption patterns using large potted plants inspired the Experiment Station, which is operated by the University of Georgia, to acquire its own machine. "The scanner allows us for the first time to look at the same plant, the same soil system, day after day after day, without having to dig into the system,' Verma says. "That is the real potential.'

With the help of University of Georgia entomologist Joseph Cheshire, for example, the team has done studies with lead-impregnated pesticide granules in order to see how various tillage operations affect pesticide distribution. "The granules show up as pinpoints in the image,' says colleague William Tollner. "So we're actually able to take soil samples and look at the profile to find out where these chemicals go in relation to the plant material and in relation to where the insects tend to be.'

Another ongoing study has the CAT scanner detecting bruises on fruits and vegetables before the bruises become visible to the unaided eye (SN: 5/12/84, p.300). Verma and Tollner hope to discover at what point in the harvesting and distribution process most damage occurs. With that information, handling procedures can be improved or damaged produce can be removed from distribution before it is transported to market.

Also under examination in the Experiment Station's heavily shielded room: analyses of water uptake by different types of roots and a look at some of the finer details of soil-seed contact during seed germination.