Effects of susceptible and resistant cultivars on PCN (G rostochiensis Ro1) and on potato yields in Australia

Transcription

1 Effects of susceptible and resistant cultivars on PCN (G rostochiensis Ro1) and on potato yields in Australia Potato Disease Workshop - 19 th Australasian Plant Pathology Society Conference, Auckland NZ, November 2013 This is a placeholder image. To replace either right click and select change picture or insert a new picture via the insert menu and crop to size. Images are available from: or Dolf de Boer

2 Acknowledgements Funding - Department of Environment & Primary Industries Victoria Potato grower on whose property the trials were conducted Crop Health Services - cyst and eggs extraction & counts F Thomson, WS Washington, DV Beardsell, NS Crump, JK Wainer, L Nambiar, S Norng, M Hannah, SL Kreidl and AL Yen UK Ministry of Agriculture, Fisheries and Food Potato Cyst Nematode: A management guide

3 The problem 1991 first record in Victoria Globodera rostochiensis Ro1 (G. pallida?) Several fields and/or properties east of Melbourne (49) History of frequent potato cropping Subject to quarantine and trade restrictions Management Out of production! Fumigation! Continued cropping - high infestations (one district)! New detections - low infestations - management of seed, ware and processing

4 Life cycle of the potato cyst nematode

5 Managing PCN? National approach! Quarantine Rotation Fumigation/nematicides Trap crops Resistant varieties H1 gene G. rostochiensis Ro1 (G. pallida?)

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7 Effect of resistant varieties Natural decline (spontaneous hatching) 12-30% per year Resistant cultivars 80% per year 50% in first year, 35% per year thereafter Damage thresholds 2 eggs/g soil 20 eggs/g soil

8 Susceptible and Resistant varieties Variety Market Rating Maturity Trent Crisp S EM Coliban Ware S L Sebago Ware S ML Altantic Crisp R (9) ML Crop 13 Ware R (9) L Moonlight, Golden Delight Nicola (Ware) Ware R (9) M

9 Distribution of PCN cysts in a trial plots, Gembrook

10 COLIBAN TRENT NICOLA ATLANTIC SEBAGO CROP 13

11 Cysts on the roots of a susceptible variety

12 Numbers of PCN cysts & eggs Trial Cysts/500 g soil Eggs/g soil 08/09 Planting (544) (111) 08/09 Harvest (623) (128) 09/10 Planting (948) (119) 09/10 Harvest (1628) (151) Average (936) (127)

13 Been and Schoemaker 2000

14 Frequency distribution, eggs/cyst 2009/10 trial

15 Eggs/g soil 2009/10 Difference in numbers of viable PCN eggs between planting and harvest of PCN susceptible and resistant potato varieties Gem brook 2009/10 No. of viable PCN eggs/g dried soil Trent S Sebago S Coliban S Fallow Atlantic R Crop 13 R Nicola R Potato variety (S, susceptible; R, resistant) At planting At harvest Difference

16 Predicted means eggs/g soil 2009/10

17 Predicted means eggs/g soil 2009/10

18 Marketable Yield 2009/10

19 COLIBAN TRENT NICOLA ATLANTIC SEBAGO CROP 13

20 The problem Light infestations (1 egg/ g soil) highest multiplication rate Rate is highest at low non-damaging population densities (50-70 times or more) High population densities ( eggs/g) affect yield but have lower multiplication rates damage to roots and increased competition between juveniles Good crop growth can support increased multiplication rates More vigorous root systems!

21 Management? Fumigants & Nematicides Rotation Natural decline rates 10-40% per year - spontaneous hatching, juveniles die after some weeks 10 or more years for population to decline to safe level! Decline rates in AUS? Resistant varieties (H1 gene for Gr Ro1) Root exudates stimulate hatching (no reproduction) Reductions of 80-90% after each crop (depends on viable cysts, the proportion of eggs that do not hatch etc.) plus natural decline in the rotation

22 Managing PCN Heavy infestations Fumigants and/or nematicides? Trap crops (potatoes and other Solanaceae) Resistant varieties Rotation Light infestations (No potato cropping?) Resistant varieties Rotation

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24 Effects of susceptible and resistant cultivars on PCN (G rostochiensis Ro1) and on potato yields in AUS 19th Australasian Plant Pathology Society Conference, Auckland NZ, November 2013 This is a placeholder image. To replace either right click and select change picture or insert a new picture via the insert menu and crop to size. Images are available from: or

25 Track top of hill Trial plan Gate 4-row plots West 0m Border Row Row1Rep1 COLIBAN Row2Rep1 CROP 13 Row3Rep1 SEBAGO Row4Rep1 ATLANTIC Row5Rep1 NICOLA Row6Rep1 TRENT Border Irrigation Track 10m Row1Rep2 Row2Rep2 Row3Rep2 Row4Rep2 Row5Rep2 Row6Rep2 SLOPE ROWS House adjacent to fence COLIBAN SEBAGO CROP 13 TRENT ATLANTIC NICOLA SLOPE ROWS 20m Row1Rep3 Row2Rep3 Row3Rep3 Row4Rep3 Row5Rep3 Row6Rep3 South NICOLA COLIBAN SEBAGO TRENT ATLANTIC CROP 13 North 30m Row1Rep4 Row2Rep4 Row3Rep4 Row4Rep4 Row5Rep4 Row6Rep4 NICOLA ATLANTIC TRENT CROP 13 COLIBAN SEBAGO 40m Row1Rep5 Row2Rep5 Row3Rep5 Row4Rep5 Row5Rep5 Row6Rep5 ATLANTIC COLIBAN TRENT CROP 13 NICOLA SEBAGO 50m Row1Rep6 Row2Rep6 Row3Rep6 Row4Rep6 Row5Rep6 Row6Rep6 CROP 13 NICOLA SEBAGO TRENT COLIBAN ATLANTIC 60m ATLANTIC NICOLA SEBAGO TRENT COLIBAN CROP13

26 Frequency distribution, eggs/cyst 2008/09 trial

27 Difference in the number of viable PCN eggs between planting and harvest of PCN susceptible and resistant potato varieties in a field trial at Gembrook 2008/ At planting At harvest Difference 200 No. of viable PCN eggs/g of dried soil Trent S Sebago S Coliban S Atlantic R Crop 13 R Nicola R Potato variety (S, susceptible; R, resistant)

28 Predicted means viable eggs/g soil, 2008/09 (ReML analysis of variance components)

29 Predicted means eggs/g soil, 2008/09

30 Effect of time: planting harvest 09/10

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