Something is causing my potato crops to be affected by zebra chip. My tubers have black, zebra-like stripes in their flesh and the outcome for me has been decreased sales. Why is this happening, and what can I do to eliminate this problem?

— Annoyed in Gaines County, Texas

Those zebra-like stripes are indeed signs of zebra chip, caused by bacterium that is vectored by potato psyllids. While this issue has been limited to only a few areas of the southern U.S. in the past, zebra chip was found in some areas of the Pacific Northwest in 2011. The key to sustaining a healthy crop will be to understand the cause of zebra chip, and develop an action plan to reduce or eliminate psyllid population during the growing season.

So, what are potato psyllids? They are small insects, about three millimeters long that feed on your crop. The three life stages of the psyllid (egg, nymph, adult) are found on potato plants, and move to new plants throughout the season. Psyllids are most likely to infest potatoes during tuber initiation or times of drought stress. If left untreated, psyllid population will increase, and yield losses of 85 percent or more might be experienced. Early zebra chip infections can lead to no tuber production, and late zebra chip infections can impact tuber chip and fry quality.

Management of the zebra chip problem depends on effective control of psyllid population, so adopt an aggressive scouting and chemical-control program throughout the season, beginning with pre-plant operations and continuing until right before harvest. Be sure to follow your local guidelines for timing and sampling procedures. A seed treatment insecticide/fungicide, like CruiserMaxx® Potato, can protect your crops from potato psyllids and other insects along with disease pathogens, offering broad insect and disease control all the way through the season.