Nematode Diseases of Perennials

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Nematode Diseases of Perennials Management Dr.
James A. LaMondia Plant Pathologist/Nematologist
The Connecticut Agricultural Experiment
Station, Valley Laboratory Windsor, CT
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Perennials Nematode Management

• Thresholds lower than annuals
• Fewer chances for control
• Host differences perennial roots

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Nematode Disease Management

• Preventative approach best
• Sanitation and inspection
• Rotation with resistance
• Root pruning
• Heat treatment

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Nematode Disease Management

• Sanitation and inspection
• Host status evaluation
• Labor-intensive inspection can
• focus on common susceptible
• species

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M. hapla highly susceptible

• Acanthus Aconitum Ajuga
• Astilbe Cimicifuga Coreopsis
• Clematis Geranium Heliopsis
• Iris Ligularia Lobelia
• Salvia Stachys Veronica

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M. hapla resistant

• Achillea Asclepias Aster
• Digitalis Echinacea Gaillardia
• Iris Liatris Liriope
• Monarda Papaver Penstemon
• Phlox Primula Rudbeckia

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Nematode Disease Management

• Rotation with resistance
• Can non-host plants reduce
• root-knot populations in soil ?

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Greenhouse resistance screen

• Rate for galls after two months
• 98 spp in 85 genera
• 29 resistant (no galls) 46 susceptible (gt
  11 galls)
• remainder intermediate

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Effect of Resistance on Meloidogyne hapla

• Inoculate with 10,000 eggs/pot
• 2 -6 months growth, bioassay
• Evaluate root galling and egg production.

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Effect of Resistance on M. hapla

• Genus Galls/plant Galls/g root
• Aster 0 0
• Coreopsis 321 18
• Lobelia 2576 87
• Rudbeckia 0 0

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Nematode Disease Management

• Root pruning
• M. hapla J2 typically infects
• at or near root tips. Can pruning reduce
  infection?

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Effect of Root Pruning on Meloidogyne hapla

• Inoculate with 10,000 eggs/pot
• Three months growth, root prune, two months
  growth
• Evaluate root galling and egg production.

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Effect of Root Pruning on M. haplaGeranium

• Fine roots pruned Galls Eggs
• 0 40.3 10,411
• 50 18.7 2,228
• 75 21.4 4,460
• 100 2.9 43

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Effect of Root Pruning on M. hapla

• Galls/g root Eggs/g root
• Genus Pruned Not Pruned Not
• Aconitum 0.0 8.5 0.0 404
• Ajuga 0.0 15.9 0.0 361
• Anemone 0.0 71.7 0.0 13,902
• Trollius 0.2 1.8 0.0 790

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Hot Water treatment M. hapla

• Large tank submersion
• Temp variation /- 0.5 C
• Cool in 15-17 C after treatment
• Astilbe and Hosta 45 C 60 min and 47 C for
  30 min effective
• 49 C for 30 min - plant death

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Root-Knot Management

• Preventative approach best
• Sanitation and inspection
• Rotation with resistance
• Root pruning/Heat treatment
• Plant Breeding/Selection

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Nematodes Infecting Perennials

• Meloidogyne hapla - root-knot
• Aphelenchoides - foliar nematodes
• Ditylenchus - stem/bulb nematodes
• Pratylenchus - lesion nematodes

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Foliar Nematode Management with Insecticides

• Avid 0.15 EC (abamectin)
• spider mites 4 fl oz/100 gal
• leafminer rate 8 fl oz/100 gal
• Diazinon AG500 1.5 oz/3 gal
• Spray to complete coverage

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Treatment ppm ai sprays A. fragariae

• Control 0.0 - 35.7
• Avid 5.6 1 6.7
• Avid 5.6 2 1.9
• Avid 11.2 1 19.5
• Avid 11.2 2 0.0
• P 0.04

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Ditylenchus per g leaf tissueTreatment ppm ai
1-4 sprays 5-6

• Control 0.0 482 215
• Avid 5.6 257 693
• Avid 11.2 485 164
• Diazinon 5.6 187 2
• Diazinon 11.2 226 5

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Foliar Nematode Management with Peroxides

• ZeroTol or Oxidate
• 27 hydrogen peroxide
• Evaluate toxicity in vitro
• Evaluate efficacy in vivo

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ZeroTol Efficacy vs Aphelenchoides in vitro
evaluation

• Dilution Viable (24 hr) (48 hr)
• control 94 76
• 1200 1 0
• 1100 0 0
• 150 0 0

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ZeroTol Efficacy vs Aphelenchoides A.
fragariae per g Anemone leaf

• Dilution 1 2 3
• control 113 113 150
• 1100 639 1208 872
• 150 1657 3988 780

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Foliar Nematode Management with
Insecticides/miticides

• Pylon new miticide for ornamentals
• 21.4 chlorfenapyr
• Label for foliar Aphelenchoides
• Efficacy similar to Avid

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Foliar Nematode Management

• Preventative approach best
• Sanitation and inspection
• Reduce overhead watering
• Insecticide treatments
• Suppression of nematodes

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Nematodes Infecting Perennials

• Meloidogyne hapla - root-knot
• Aphelenchoides - foliar nematodes
• Ditylenchus - stem/bulb nematodes
• Pratylenchus - lesion nematodes

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Lesion Nematode Management

• Primarily field-grown problem
• Pre-plant sampling
• Rotation - suppressive plants

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Lesion Nematode Management

• Preventative approach best
• Sanitation and inspection
• Rotation with suppressive plants
• Rudbeckia hirta Polynema marigold
• Fumigation