1. Impact of psyllid on potato production in new Zealand
Tomato Potato psyllid
Impact of psyllid on potato production in new Zealand
Good Afternoon Ladies & Gentlemen, you have just heard from Kevin Clayton-Greene in regards to the biology of the psyllid, liberibacter & phytoplasm, I am going to discuss its impact in NZ & our reaction to it. (My name is Monty Spencer R&I manager for A S Wilcox & Sons we) (Wilcox’s) mainly grow potatoes, onions & carrots in 3 main locations in the NI & 1 location in the SI on the Canterbury Plains near Chch. We also have packhouses just south of Auckland, Pukekohe to service the NI, & a packhouse on the Canterbury Plains to service the SI. Most of our onions are exported & some of our carrots.
Stephen Ogden is a private contractor, contracted to Potatoes NZ, to manage the industries response to the Psyllid incursion.
Monty Spencer
A S Wilcox & Sons Ltd
Stephen Ogden
Market Access Solutionz Ltd

2. Psyllid in New zealand NZ potato industry
Timeline since psyllids found
Impacts on industry
Research & extension programme
A S Wilcox Reaction
Brief outline & location of the potato growing in NZ, Timeline tracing the discovery of Psyllids in NZ, the resulting R&D programme, & finally how we reacted to it.

3. Potatoes in nz 10,500 ha (26,000 acres) 500,000 tonnes 290 growers
Varieties
Processing –
Fries: Moonlight, Russet Burbank, Ranger Russet, Bondi etc
Crisps: Fianna, Fraser, Lady Rosetta, Snowden, Ivory Crisp etc
Table: Nadine, Frisia, Rua, Desiree, Karaka, Agria, Red Rascal, Ilam Hardy, Draga etc
Processed 300,000, Fresh 200,000t, Many varieties are grown this is a selection of some of the more prominent ones

4. Pukekohe Waikato Ohakune Hawkes Bay Manawatu Canterbury
Working south the major growing areas in NZ are: Pukekohe, Waikato specifically Matamata, Ohakune, Hawkes Bay, Manawatu & in the Canterbury Plains in the SI.
From Pukekohe North potatoes can be grown thru the winter as well as in the summer. South of Pukekohe potatoes are grown over the summer period & are called main crop potatoes. Discussion in this paper concentrates on Main Crop potatoes. Auckland is on the same latitude south as Bendigo, Northern Tassie the top of the SI
Canterbury

5. Timeline Since Psyllid Found
Tomato potato psyllid (TPP)(Bactericera cockerelli) detected in Auckland
In greenhouse tomato crop
Survey detected psyllid in more greenhouse tomato crops, capsicum & volunteer potatoes
Psyllid sugars, yellowing
Determined to be too widespread to be eradicated
Over to industry to manage
Detected in tomato glasshouse in Auckland area first, tomatoes looked poorly with symptoms similar to described by Kevin.This lead to more intensive searches it was then discovered outside the glasshouse in potato crops adjacent but then in Capsicum crops north of Auckland & in the Auckland urban area. At this point it was determined it was to widespread to contain

6. 2007-8 Candidatus Liberibacter solanacearum detected in greenhouses
Death of tomato plants
Minor damage in peppers
Export markets closed
Impacts on pepper, tomato & potato exports
TPP confirmed to be the vector
Little impact in potato industry in 2008 harvest
Detected in research potato crops
Major impacts on glasshouse tomatoes & capsicums with export markets closed off. In potato crops there was a considerable the research station in Pukekohe, but there was very little effect on commercial crops. It could have been the research stn first because more careful monitoring for insects was being carried out, but it could also have occurred as some of the trials had lower, to little insecticide programme.

7. season
Things became serious…
And confusing

8. season
Candidatus Phytoplasma australiense detected in potatoes – early 2009
Native species – cabbage tree decline
Symptoms similar to potato purple top & stolbur
Causes grapevine yellows in Australia
Assumed to be causing damage in potatoes
Plant hopper vector
Did psyllid have a role too?
The phytoplasma detected was already present in NZ & had been for quiet a while, as it had been extensively studied on native species particularly cabbage trees. but symptoms associtated with it seemed t be more prevalent than it had been previously. There was considerable debate if it was exhibiting symptoms more obviously than previously because of the presence of psyllids &/or liberibacter. In the USA it was generally considered that it was highly unlikely that psyllids were transferring the phytoplasma because it had not been reported previously that psyllids had that capacity. It was felt that the vector was more likely to be a plant hopper, however plant hoppers were rarely seen in NZ potato paddocks.

9. Phytoplasma ?
Were these symptoms being caused by psyllids, some would call this psyllid yellows, that is the mere act of psyllids feeding on the plant, or was it caused by phytoplasma?

10. season
Phytoplasma coincided with onset of serious damage caused by psyllid yellows and Liberibacter
Confusion of symptoms and causes
Full impact of the psyllid/ Liberibacter / Phytoplasma was realised
Diagnostics
Trying to resolve this dilemma meant being able to reliably detect phytoplasma & Liberibacter & this was proving more difficult than expected.Reliable detection was proving elusive. When different parts of the plant & even different parts of the same tuber & retests were carried out results differed between –ve & +ve. Nested PCR & real time PCR was being used. This meant that samples being sent in for analysis by growers, factories, could not be analysed with confidence. Even thru the USA seemed to be getting consistent & repeatable results for its presence or absence. These were not quantitative tests

11. 2009-10 season Better prepared? New advisory materials to growers
Series of workshops pre-season
Research programme underway
Psyllid monitoring
Diagnostics
We went into this season with the diagnostic still unresolved but some leads. A modified PCR test was developed that allowed quantitative analysis. This was a major breakthrough. It allowed us to find that most psyllids have some degree of liberibacter tita. What was thought to be cold psyllids (psyllids with no liberibacter being carried) were now found to be varying degrees of warm to hot. Similarly for the plants.
USA scientists, who had been working on the problem for a no of yrs were brought over, & made grower meetings as well as meeting NZ scientists & studying field infections.

12. 2010-11 Season Had considerably better handle on the problem
Psyllid Monitoring
Diagnostics
Series of workshops pre & during season
Refinement of Research Programme
Plant Protectants
Beneficals
Spray coverage
In regards to the results being obtained from the diagnostics it is now suspected that although phytoplasma can be present in the potato, & it could accentuate the problem, it is not the primary problem. Rather Liberibacter is the problem. The sampling system for plant analysis still needs to be refined because it appears that tita of liberibacter is very variable throughout the plant.

13. Psyllid monitoring
Nadine Berry, Plant & Food Research, Lincoln
Sticky traps are put around the margins of paddocks, that is on the 4 sides (4 traps) & inspected wkly for psyllids

14. Peak numbers of adult psyllids per trap site (ave) per week 2009-10
Peak numbers/wk, ave of the 4 traps in the highest wk.
NZ obviously gets colder as you go south
However the westerly is the prevailing wind, with higher rainfall & more humidity & more equitable temperatures.
In contrast the East coast is drier with lower humidities with more extreme temperatures, probably more similar to much of Oz?
So in some ways it is not surprising that there are high psyllid nos on the East Coast in HB. Another complication is that in HB there are considerable areas of field tomatoes grown, psyllids love tomatoes more than potatoes.
5/trap

15. Peak ave numbers of adult psyllids per trap per week 2010-11
Large increase in Pukekohe, pressure slightly lower in Waikato/Matamata, HB psyllid nos significantly lower, in Manawatu there was a peak the end of the season (next slide), & in the SI nos have increased 3* but from a very low base. The trap intensity is very high in the SI & it is apparent that the background level does seem to be building
However it is important not to read to much into the absolute figures because they are very variable & strongly influenced by a growers spray & irrigation programmes well as climate patterns such as rainfall & temperatures
The 323 in Manawatu is probably abit of an outlier – I wonder what the spray programme was this site.
15/trap

16. This gives a feel of population dynamics thru the season
This gives a feel of population dynamics thru the season. In most regions it is possible to pick out 4 generations. Because of the confounding variables such as rainfall, irrigation, spray programes etc often sticky trap numbers do not correlate very well with nos found in the crop.

17. Infected tubers showing the prominent vascular bundle browning
Infected tubers showing the prominent vascular bundle browning. The more severe the infection the more internal browning there is.

18. Cost to industry 2008-9 cost to industry $46 million 2009-10
Reduced yield
Rejects from processing
Additional control costs (too late to save crops)
High psyllid numbers
Continued rejection or downgrading by processors
Zebra chip
Low solids
Costs were initially estimated, the industry is due to update these costs

19. Costs 2009-10 No devastating crop losses Increased insecticide costs
Est NZ$ 700/ha (US$200/ acre) average
Increased application costs
New equipment – increased spray frequency
However insecticide spray programmes can easily be over $1200/ha, growers with programmes under $500/ha might well have had holes & psyllid nos.

20. COSTS 2010-11 No devastating crop losses
Increased insecticide costs but less than previous season
Damage still evident in factory
Effect on yields & perhaps solids
@ the Simplot factory in Auckland they have taken on 9 extra permanent field & testing staff to handle the situation times have had another 10 staff in factory grading out infected tubers.

21. Research roadmap Purpose: To confirm research direction
Ensure no gaps in research or funding
A research rdmap was constructed to help understand where research needed to be targeted & the likely costs to undertake the research

22. The rd map looked like this, divided into 5 areas Preplant, preharvest, Post harvest, Research tools & Extension

23. Pre-plant Decision guides Seed selection criteria*
Site selection and management*
@ first it was not known whether Liberibacter was intergenerational, that is liberibacter was transferred to daughter progeny
Work in the USA seemed to indicate that it could not however NZ work has shown that it can be
Therefore seed selection is very important.

24. Pre-harvest Low-cost diagnostics
Effective control – insecticides & coverage*
Monitoring & action thresholds
BCAs & IPM
Host plants & cultural management
Alternative vectors and management
Seed transmission – Liberibacter & Phytoplasma
Role of Liberibacter & Phytoplasma in management*
Resistant varieties*
We have already discussed the more reliable faster diagnostic test.
There have been trials carried out on an IPM approach, with threstholds for spraying. The thresthold set last season was to high & once the psyllid had become established it was impossible to wipe it out. Threstholds have been lowered this season, the results have yet to be analysised.

25. Post-harvest Working to identify what needs to be done
Detect/ segregate defects at harvest
Techniques to detect / segregate in factory
Improved methods to process defect tubers
We have already discussed the increased costs in the factory. Once the potato has been peeled it is relatively easy to detect ZC infection. Various proposals have been put forward on how to automate the grading process

26. Research outcomes to date
Grower summary in “Psyllid News”

27. Psyllid response - Extension
Psyllid News
Primary means of communicating new research outcomes
Quarterly publication

28. Psyllid response - Extension
“Psyllid Coordinator” role established
Research coordination
Liaison between scientists & growers
Grower materials – guidelines on:
Psyllid / Liberibacter / Phytoplasma complex
Control
Monitoring
Hosts
Grower field days and meetings
To ensure the response to psyllids was well coordinated Stephen Ogden was appointed 2 seasons ago to manage & develop a programme.
The R&D effort has been partly funded by PotatoesNZ plus extra funding by way of a special psyllid levy of $1/t of potatoes. Government grants have also been obtained plus Plant & Food Research has put $ in of their own

29. A S Wilcox Reaction Growing Seasons:
2008/9 Emerging issue but not a major for us: Industry “Normal Insecticide Programme”
Planter insecticide
Pre-harvest insecticides – PTM
Sometimes aphids from mid season
Irrigation used to try & avoid stressed plants

30. Reaction Continued 2009/10 Growing Season Spraying weekly fungicides
Started spraying weekly with insecticides
Typical Programme
Pre-plant Actara
Early Emg – Confidor
Every 7 days: Movento 2*, Avid, Oil, Oberon 2*, Avid, Oil, Tamaron, Karate, Alternating Total 18 sprays
Control
Not surprisingly we got very good control with this programme. Cost was in the order of $1200/ha

31. Reaction Continued 2010/11 Growing Season
Industry monitoring, Commercial Monitoring
Pre-plant – Actara
50% Canopy or on 1st sight: Movento, 2 wks later Movento, 2 wks later Avid, 1 wk later Oberon, 2wks later Oberon, 2 wks later Tamaron/Karate alternating. Total 8-10 sprays
Excellent Control
This season we wanted to reduce our spray programme partly because of cost but also because to pt something in place that was more sustainable.
However to enable us to do that with confidence, as well as the industry sticky trap monitoring scheme, we contracted a commercial firm to undertake weekly monitoring in the crop, that is counting psyllids on the foliage.
@ 50% canopy 1st sight of psyllids in the crop we started spraying& then keep going for the rest of the season

32. Monty Spencer Stephen Ogden monty@aswilcox. co. nz stephen@solutionz
Monty Spencer Stephen Ogden