Idaho Agricultural Experiment Station UI College of Agricultural and Life Sciences Image Map
 

Results to date of sticky card captures from the ca. 90 fields being monitored with 4 yellow sticky cards can be found here.

Results to date of sticky card, vacuum, and leaf samples from 13 fields being monitored can be found here.

Regular update summaries (see below) will be extended to stakeholders; however, to obtain the most up-to-date and detailed information on trap captures, the links above can be checked at any time for periodic updates over the week.

–  Erik Wenninger

August 30, 2013 — first ZC-positive plant in Idaho this year confirmed

Last week we reported finding a plant at the Kimberly R&E center that exhibited classic zebra chip symptoms. A tuber sample from this plant tested positive for Lso, the zebra chip pathogen. This represents the first confirmed case of a zebra chip positive plant in Idaho this year. The potato was infected with type B Lso; all previous samples from Idaho were type A. There are two geographically based biotypes of Lso that infect potato (A and B); differences between the biotypes in relation to biology and management remain to be fully clarified.

We continue to catch psyllids on sticky traps across the U-Idaho monitoring program. A few traps remain to be read from this week’s sampling; however, thus far there have been no psyllids found in counties from which we had not previously found psyllids. Psyllid numbers are on the rise on some fields, notably in Canyon County.

More potato psyllids have tested positive for Lso. Lso-positive psyllids were found during the week of August 12 in the following counties: Canyon, Ada, Twin Falls, and Minidoka. Thus far, no Lso-positive psyllids have been found in eastern Idaho, though an additional psyllid was found this week in Power County that remains to be tested.  –  Erik Wenninger

August 23, 2013 — ZC-suspect plant found at Kimberly R&E Center

Today, August 23, at least one plant was observed at the Kimberly Research and Extension Center displaying classic zebra chip foliar and tuber symptoms. Samples are currently being tested for the presence of the Lso bacterium that causes zebra chip. Refer to http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/ for additional information on potato psyllids scouting efforts and zebra chip symptom identification.

Potato psyllid numbers on sticky traps continue to rise across the U-Idaho monitoring program. A few traps remain to be read from this week’s sampling; however, thus far there have been no psyllids found in counties from which we had not previously found psyllids. –  Erik Wenninger

August 16, 2013 — first potato psyllids found in eastern Idaho

Potato psyllids were trapped for the first time in eastern Idaho this week, one each in Power and Bingham counties. Incidence still remains low (less than 2%), as only six psyllids have tested positive for Lso out of the 300 trapped in our monitoring network throughout southern Idaho. To date, psyllids have now been trapped in Owyhee, Canyon, Ada, Elmore, Gooding, Jerome, Twin Falls, Cassia, Minidoka, Power, and Bingham counties. All psyllids collected last week tested negative for Lso, the bacterium that causes zebra chip disease.  –  Erik Wenninger

August 9, 2013 — psyllid captures continue to rise, but no new Lso-positive psyllids found

More potato psyllids were trapped this week in potato fields in Owyhee, Canyon, Ada, Elmore, Gooding, Jerome, Twin Falls, and Cassia Counties. Over 200 psyllids have been collected in our monitoring network so far this summer, and only six have tested positive for Lso, the bacterium that causes zebra chip disease. Those six Lso positive psyllids were trapped in Canyon, Jerome, and Twin Falls counties. This is relatively low incidence (less than 3%) compared to last year. All psyllids trapped last week tested negative for Lso.

August 2, 2013 — more Lso-positive psyllids found

More potato psyllids were trapped this week in potato fields in Canyon, Ada, Elmore, Gooding, Jerome, Twin Falls and Cassia Counties. Results from last week show three more positives for Lso, the bacterium that causes zebra chip, but incidence of Lso remains low (less than 5%).  –  Erik Wenninger

July 26, 2013 — first potato psyllids found in Owhyhee and Minidoka counties

More potato psyllids were trapped this week in potato fields in Canyon, Ada, Elmore, Gooding, Jerome, and Twin Falls Counties. In addition, we trapped our first potato psyllids this week in Owyhee and Minidoka Counties. In addition to the counties listed above, in a previous week we had also captured a psyllid in Cassia County. All the psyllids tested from last week were negative for Lso, the bacterium that causes zebra chip. So far, over 100 potato psyllids have been collected this year in U-Idaho monitoring programs; of the 64 psyllids tested so far, only 3 have been positive for Lso (less than 5% incidence). In contrast, by this time last year roughly 50% of the psyllids collected were positive for Lso. It is important to note, however, that despite finding only a handful of Lso+ psyllids in the Columbian basin last year, zebra chip was still found.  –  Erik Wenninger

July 19, 2013 — more potato psyllids found in Ada, Canyon, Elmore, and Twin Falls counties

More potato psyllids were trapped this week in potato fields in Ada, Canyon, Elmore, and Twin Falls counties. The number of psyllids collected per trap and per field remains relatively low; however, they are in line with trap counts from this time last year. It remains to be seen whether a similar increase will be observed this year, but last year’s sticky trap captures increased dramatically through August and September.

We are still waiting on results from Lso testing from psyllids collected during this and last week.  –  Erik Wenninger

July 16, 2013 — potato psyllids tested positive for Lso

For the first time this year we have found potato psyllids in Idaho that have tested positive for Lso, the bacterium that causes zebra chip. A total of three individual psyllids tested positive from early July: one in each of two fields in Canyon County and one collected at the Kimberly R&E Center.  –  Erik Wenninger

July 12, 2013 — potato psyllid found in Cassia County

As always, detailed results of monitoring efforts can be viewed using the links above.

Potato psyllids were trapped this week on sticky cards in Canyon, Ada, Elmore, Twin Falls, and Cassia Counties. This was our first potato psyllid captured this year in Cassia County. So far no psyllids tested to date have been positive for the bacterium that causes ZC. We are still waiting on results from psyllids collected during this and last week.  –  Erik Wenninger

July 5, 2013 — more potato psyllids found in Magic and Treasure Valley

As always, detailed results of monitoring efforts can be viewed using the links above.

More potato psyllids have been found in the U-Idaho monitoring programs. Psyllids have been found thus far in Canyon, Ada, Elmore, Gooding, Jerome, and Twin Falls Counties. So far no psyllids tested to date have been positive for the bacterium that causes ZC.  –  Erik Wenninger

June 28, 2013 — potato psyllids found in Magic Valley; psyllids tested so far all negative for bacterium

As always, detailed results of monitoring efforts can be viewed using the links above.

Among the ca. 90 fields being monitored across the state with 4 sticky traps, more potato psyllids were found in Canyon and Elmore Counties, and 1 potato psyllid was found in Jerome County. All psyllids tested so far from previous weeks have been negative for Lso, the bacterium that causes zebra chip.

Among the 13 fields being sampled with 10 sticky cards, vacuum samples, and leaf samples, more potato psyllids have been found in Canyon County, and 1 potato psyllid was found in Twin Falls County. All psyllids tested so far from the previous week have been negative for Lso, the bacterium that causes zebra chip.  –  Erik Wenninger

June 21, 2013 — more potato psyllids found in western Idaho potato fields

Among the ca. 90 fields being monitored across the state with 4 sticky traps, 1 potato psyllid was found in a field in Elmore County this week.

Among the 13 fields being sampled with 10 sticky cards, vacuum samples, and leaf samples, 1 potato psyllid was found in a field in Ada County and a total of 3 potato psyllids was found across two fields in Canyon County this week.

Any scouting programs underway for potato psyllids should be intensified, and IPM programs should be in place. Refer to the following site for guidance on scouting and IPM programs for potato psyllids: http://extension.uidaho.edu/kimberly/tag/potato-psyllid-and-zebra-chip/  –  Erik Wenninger

June 14, 2013 — 1 potato psyllid found in Canyon County potato field

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state initiated a scouting program during the week of May 13 that covers commercial potato fields throughout southern Idaho. The project is funded in part by ISDA and IPC. Thirteen fields are being monitored with 10 yellow sticky cards, vacuum samples, and leaf samples. With cooperation of several crop consultants, approximately 90 additional fields are being monitored with 4 yellow sticky cards. Among these ca. 90 fields, one potato psyllid was found on a card in Canyon County last week. This psyllid will be tested for Lso, the bacterium that causes zebra chip. –  Erik Wenninger

June 7, 2013 – No potato psyllids detected in Idaho potatoes yet

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state initiated a scouting program during the week of May 13 that covers commercial potato fields throughout southern Idaho. The project is funded in part by ISDA and IPC. Thirteen fields are being monitored with 10 yellow sticky cards, vacuum samples, and leaf samples. Approximately 90 additional fields are being monitored with 4 yellow sticky cards; scouting efforts in some fields (especially in eastern Idaho) are still being initiated. Thus far, no potato psyllids have been found in any samples from potato fields; however, this week one adult potato psyllid and numerous psyllid eggs were observed on bittersweet nightshade in Twin Falls. This is not surprising given the apparent ability of psyllids to overwinter in association with this alternative host plant. Next week we will provide access to an online spreadsheet that shows results of the potato field monitoring efforts and location of fields (by county). –  Erik Wenninger

May 24, 2013 — UI potato psyllid monitoring started

The University of Idaho, in collaboration with Miller Research and several crop consultants across the state, has initiated a scouting program that covers commercial potato fields throughout southern Idaho. The project is funded in part by ISDA. The primary means of sampling psyllids will be by the use of yellow sticky cards, although vacuum samples and leaf samples are being taken from some fields as well. The first traps were deployed during the week of May 13; thus far, no potato psyllids have been found in any samples. Details of the monitoring program and results of monitoring efforts (by county) will be available soon. –  Erik Wenninger

April 12, 2013 — Potato psyllids found in the Magic Valley

Several natural or semi-natural areas near Twin Falls are being monitored during the winter for potato psyllids. Sites were selected near watercourses where the alternative host plant bitter nightshade is found. Thus far, no psyllids have been found in direct inspection of plants; however, two adult potato psyllids were found on a yellow sticky trap near Shoshone Falls in late March. Whether these psyllids overwintered or have migrated to our area is unknown. They will be tested for liberibacter, the bacterium that causes ZC, and monitoring efforts will continue through the season.  –  Erik Wenninger

March 12, 2013

A recent submission of potato tuber samples grown in Power County were verified to be positive for Lso (Candidatus Liberibacter solanacearum), the bacterium causing zebra chip in potatoes. Symptoms of zebra chip include necrotic flecking in the flesh of the tuber, similar to net necrosis, but the symptoms extend throughout the length of the tuber. When diseased tuber tissues are fried, severe darkening in both chips and fries are seen. Because symptoms can be seen in uncooked tissues, the disease is a concern for both fresh and process potatoes. The number one means to control zebra chip is to control infected potato psyllids. Non-infected psyllids will not cause zebra chip.

For more information contact Nora Olsen or Erik Wenninger

 April 19, 2013