08/09/05 Chemical interaction in spud fields

Farm and Ranch August 9, 2005 This year scientists at the University of Idaho launched a two-year study to find out whether and how insecticides, fungicides and herbicides interact in potato fields. Mike Thornton, plant physiologist and superintendent at the Southwest Idaho Research and Extension Center at Parma, says it is known that product interaction in other crops can have negative effects. Thornton: "It is really common for corn and soybean growers to understand that there are certain combinations of pesticides that either result in more plant injury or reduced the effectiveness of one of the products in that mix. And there are a whole bunch of new chemistry available in potatoes and nobody has really looked at that aspect in a comprehensive study. And that is what we hope to do is look at a bunch of the new fungicides, insecticides, herbicides and see if we get some of the same kind of interactions." At Aberdeen, weed scientist Pamela Hutchinson says one possible interaction is that a herbicide applied after planting may interfere with the crop's uptake of a long-acting pre-plant insecticide. She says then for example, the crop wouldn't be protected against an insect like Colorado potato beetle. Not only are Hutchinson and Thornton examining every possible combination of four insecticides and two herbicides in the field, but Hutchinson is also growing potatoes and the related hairy nightshade in the greenhouse. I'm Bob Hoff and that's the Northwest Farm and Ranch Report on the Northwest Ag Information Network. .