PLPA-Pot012-01 http://zebrachipscri.tamu.edu

Zebra Chip Disease of Potato

Zebra chip (ZC) is a disease of potato that was Underground stems can exhibit vascular browning. observed in Mexico in 1994 and in Texas in 2000. Tubers may have enlarged lenticels.

Symptoms Causal Agent

Foliar symptoms can be similar to what is Candidatus Liberibacter solanacearum (CLs), a normally associated with Phytoplamas or phloem-limited, non-culturable bacterium, is Fusarium. Symptoms of ZC include: wilt, currently accepted as the causal agent of ZC. This yellowing, leaf curling, scorching, swollen nodes, pathogen is transmitted by the potato (tomato) proliferation of axillary buds, and aerial tubers psyllid, Bactericera (formerly Paratrioza) (Fig. 1). cockerelli.

Figure 3. A nymph of the potato psyllid on the underside of a potato leaf (left). Close-up of an adult and nymph (right). Photo (left): Ronald French. Photo (right): Don Henne

Other Plant Hosts Figure 1. Aerial tubers. Photo: Ronald French. Besides potato, CLs has been confirmed on tomato, Below ground, cut tubers exhibit a discoloration in pepper (Capsicum), silver and black nightshade, the medullary rays where the entire area has tamarillo, Datura, Cape gooseberry, and carrots. scattered streaks. Upon cooking, stripes are clearly visible. This is what gives this disease its Management name (Fig. 2). Currently, the only effective approach to managing ZC is to target the insect vector by using insecticides both at planting (seed treatment), by soil drenching, and by foliar applications during the cropping season. It is important to rotate chemistries and make sure that the right growth stage of the insect is targeted at the time of insecticide application

For updated information on Zebra Chip and Figure 2. Raw (left) and fried potato tuber slice (right) management of Zebra Chip, visit: showing discoloration. Photo: Ronald French. http://zebrachipscri.tamu.edu

Prepared by Ronald D. French; Assistant Professor and Extension Specialist in Plant Pathology; Amarillo, Texas. Texas AgriLife Extension Service-Texas A&M System; June 18, 2012 http://sickcrops.tamu.edu

The information given herein is for educational purposes only. References to commercial products or trade names are made with the understanding that no discrimination is intended and no endorsement by Texas AgriLife Extension Service personnel is implied. Educational programs of the Texas AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age, or national origin. The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperating.