Potato Psyllid Survey
August and September of 2009
(Click on "Dates" to see Graphs of Sampling Results)
September 8, 2009 -- Fields F5 and Tri16 are mature and leaves are dead, so no leaf sampes were taken and sticky traps were pulled from field F5. -- Waiting for samples to be processed to get counts on sticky traps.
August 24, 2009 - moderately high numbers of adult psyllids were captured on the traps in F5. F5 and Tri16 had moderate numbers of eggs and nymphs. Plants in Tri 16 and F5 were near maturity and suffering from early blight. Traps pulled from Tri 16 as numbers have declined significaltly since traps were placed in field border.
August 17, 2009 -- Harvest was under way in Tri 16 (Sticky traps in Tri16 were moved to field border in preparation for harvest last week). Moderately high numbers of adult psyllids were captured on the traps in field F5. None of the adults collected were positive for Liberibacter. F5, and Tri16 had moderate numbers of eggs and nymphs.The UTC has been harvested and scored for ZC. 588 tubers were checked for ZC symptoms (by making a cross section cutting): Row 1 (96 tubers), Row 2 (129 tubers), Row 3 (110 tubers), Row 4 (127 tubers), and Row 5 (126 tubers). None of the raw tubers exhibited ZC symptoms. A sub-sample of 20 tubers from each row were sliced into chips and fried (100 tubers in total); no ZC symptoms were observed in the fried chips. Conclusion: It appears that there was little or no ZC in the untreated check potato plots, suggesting that ZC was none or extremely low (if any) at the Garden City site.
|Harvest underway in Tri16 - August 17, 2009||Sticky trap in field margin of Tri16 - August 17, 2009|
August 10, 2009 -- Harvest was nearly complete in CLC18, and only one leaf sample was collected. Moderately high numbers of adult psyllids were captured on the traps in F5 and Tri 16. None of the adults collected were positive for Liberibacter. F5, Tri16 and CLC had moderate to high numbers of eggs and nymphs. The UTC has been harvested. Sticky traps in Tri16 were moved to field border in preparation for harvest.
F5 - August 10 --
|Harvest from CLC18|
Aug 3, 2009 -- high numbers of adult psyllids were captured on the traps especially in Tri16 and F5. No eggs and nymphs were detected in F5, but both Tri 16 and CLC18 had moderate to high numbers of eggs and nymphs. Only 4 leaf samples from CLC18 as large portion of field had been harvested. None of the adults collected were positive for Liberibacter. The EXP UTC field has been harvested by Phil Sloderbeck and the potatoes sent to Joe Munyaneza to be fried and scored for ZC.
|Harvest of EXP UTC - Aug. 2, 2009||Potatoes from row 2 of EXP UTC|
|Harvest underway in in CLC 18, August 3, 2009||Harvest underway in in CLC 18, August 3, 2009|
This research is being conducted by K-State Extension in cooperation with USDA-ARS-Weslaco. The are samples are being collected by Phil Sloderbeck, Kansas State University Extension, Garden City, KS, and processed by John Goolsby and others at, USDA-ARS, Weslaco, Texas. The molecular pathology work is being done by Jim Crosslin and Joe Munyaneza (USDA-ARS Prosser & Wapato, WA).
Adult psyllid on sticky trap.
The potato psyllid adults in each field are monitored with 5 yellow sticky card traps that are changed weekly. The traps are placed in a sequence #1 at 30 ft. inside the field with each trap placed each 200 ft towards the center of the field.
Immature psyllid on leaf.
Egg and nymphal populations of potato psyllid are sampled each week by collecting 100 mature, fully expanded, lower canopy potato leaves (4-10 leaflets) at 10 locations on the perimeter of each field.
The fields (FS, CLC18, Tri16) are commercial potato fields near Garden City, KS and UTC is small patch of potatoes at the Southwest Reseach and Extension Center to serve as an untreated control. The insecticide applications and dates are listed for each growing area by field. Adult potato psyllids are removed from the traps and tested for the presence of the putative ZC pathogen, Liberibacter psyllaurous candidatus. The percentage of psyllids that test positive for this pathogen is noted by date.