Presentation on theme: "Zebra Chip in North America a new challenge? Phillip Nolte Phillip Nolte Extension Seed Potato Specialist University of Idaho, Idaho Falls, ID UNECE Seed."— Presentation transcript:
Zebra Chip in North America a new challenge? Phillip Nolte Phillip Nolte Extension Seed Potato Specialist University of Idaho, Idaho Falls, ID UNECE Seed Potato Meeting, May 31, 2012, Edinburgh, Scotland, UK
Dr. Neil Gudmestad, NDSU Dr. Neil Gudmestad, NDSU Dr. Andy Jensen, WPC, OPC, IPC Photo and source credit ZC in North America
“Zebra Complex” or “ZC” Not just chips (crisps) Fries Fresh Seed?
Disease Diagnosis ZC in North America
ZC Symptom variability Foliar symptoms similar to purple top wilt syndrome and include: Leaf curl Leaf chlorosis and scorching Limited purpling of top leaves Twisted stems
North Dakota Texas Oklahoma New Mexico Colorado Arizona Kansas Arkansas Wyoming South Dakota Nebraska Minnesota Iowa Montana Idaho Utah Nevada California Washington Missouri Louisiana..... Oregon. Locations where ZC defect has been found in USA
Seed Production 30,000 A Seed Production 30,000 A SW 21,000 A SW SE 207,000 A SE SC 75,000 A SC
ZC Timeline for PNW September- Columbia Basin of WA/OR Idaho: Late September/Early October Norkotah sample from packing shed with symptoms. Found by ISDA inspector. Confirmed ZC. Leavings in field sampled confirmed ZC. (Jerome Co) Additional samples found in research plots in Kimberly (Twin Falls county) – 0 to 1.8% Samples from commercial fields (Twin Falls county)
Lots of positives at low incidence Most in Central ID Much lower in West Nothing from East as yet Many potatoes still in storage Current situation ZC in Idaho
WEST 21,000 A WEST SE 207,000 A SE CENTRAL 75,000 A CENTRAL ?
Tuber Symptoms ZC in North America
Tuber Symptoms G. Secor
Net Necrosis (PLRV) ZC
Defect of Chips / Crisps Disease causes browning of chips processed from affected potatoes ZC leads to load and field rejections Initially called “Texas defect” and then “Zebra Chip” due to alternating light and dark streaks in finished product Discoloration ranges from mild to severe
Causal Agent ZC in North America
“ Candidatus Liberibacter solanacearum ” (bacterium) Not culturable Spread by potato psyllid Causal Agent
Psyllid Vector ZC in North America
The Vector: Tomato-Potato Psyllid
Psyllid behavior and capabilities? Stored potatoes? Curiosity or long term scourge? Seed ??? Much is unknown ZC in Idaho
ZC has not been reported in any seed production area of Canada or USA Disease appears to be independent of seed source ZC frequently kills eyes, or produces very weak plant Studies underway to determine importance of seed borne inoculum ato-tomato psyllid native to USA west Host range – prefers Solanaceae: potato, tomato, pepper, nightshades, but can also develop on many other plants Occurs annually in WA, OR, and ID May migrate? but may overwinter here? Can be very difficult to detect in the field Importance of infected seed?