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

Nematodes Infecting Perennials Meloidogyne hapla - root-knot Aphelenchoides - foliar nematodes Ditylenchus - stem/bulb nematodes Pratylenchus - lesion nematodes

Nematode Diagnostics 30% (99 of 333) samples submitted over 5 years were infected with Meloidogyne hapla

Perennial Ornamentals > 2500 species in >500 genera. Value over $1 billion in US. Propagation by division, seed, and cuttings.

Non-specific Damage Symptoms of poor roots Poor color and vigor Reduce winter hardiness Secondary pathogens/diseases Non-specific Damage Symptoms of poor roots Poor color and vigor Reduce winter hardiness Secondary pathogens/diseases

Nematodes Infecting Perennials Meloidogyne hapla - root-knot Aphelenchoides - foliar nematodes Ditylenchus - stem/bulb nematodes Pratylenchus - lesion nematodes

Nematodes Infecting Perennials Meloidogyne hapla - root-knot Aphelenchoides - foliar nematodes Ditylenchus - stem/bulb nematodes Pratylenchus - lesion nematodes

Nematode Diseases of Tree Fruits

Nematode Damage Reduce tree vigor and yield Reduce winter hardiness Transmit viruses (TmRSV) - apple union necrosis - peach stem pitting Replant Diseases Nematode Damage Reduce tree vigor and yield Reduce winter hardiness Transmit viruses (TmRSV) - apple union necrosis - peach stem pitting Replant Diseases

Nematodes Infecting Tree Fruits Pratylenchus - lesion nematodes Xiphinema - dagger nematodes Criconemella - ring nematodes Meloidogyne hapla - root-knot

Nematode Damage Levels Lesion per 100 cm 3 soil Ring per 100 cm 3 soil Dagger per 100 cm 3 soil (depends on TmRSV)

Apple Replant Trees appear stunted, and growth uneven and slow. Associated with lesion nematodes, soil fungi and bacteria, and poor soil conditions.

Apple or Fruit Replant Disease

Ring Nematode

Apple Union Necrosis

Problem only on size-controlling rootstocks such as MM106 and scions such as Red Delicious. Shoot growth reduced, heavy set of small fruit, not always lethal.

HistoryHistory Tomato RingSpot Virus

Weed Hosts of TmRSV Common chickweed Lambsquarters White-head aster Oxeye daisy Common thistle Dandelion Wild carrot Swine or Pennycress Leafy/prostrate spurge Red or White clover Common polkweed Buckhorn plantain Common mullein Common plantain Sheep sorrel (red) Curly dock Wild strawberry Broadleaf plantain

Peach Stem Pitting Affected trees appear girdled, lose vigor and eventually die. Trees often yellow early, and set a large number of small fruit. Pits or grooves occur in rootstock.

Cultural Practices Site preparationSite preparation Rotation crops - Brassicas or sorghosudan/sudangrass.Rotation crops - Brassicas or sorghosudan/sudangrass. Sod strips - perennial rye or fescue grasses and weed control.Sod strips - perennial rye or fescue grasses and weed control.

Nematicides Need determined for each fieldNeed determined for each field Fumigant Nematicides 1,3-dichloropropene metam sodium or dazometFumigant Nematicides 1,3-dichloropropene metam sodium or dazomet Non-fumigant Nematicides Fenamiphos or oxamylNon-fumigant Nematicides Fenamiphos or oxamyl

Strawberry Black Root Rot: Plant and Pathogen Interactions James A. LaMondia The Connecticut Agricultural Experiment Station Valley Laboratory Windsor, CT Strawberry Black Root Rot: Plant and Pathogen Interactions James A. LaMondia The Connecticut Agricultural Experiment Station Valley Laboratory Windsor, CT

DISEASE TRIANGLE DISEASE Host Plant Causal Agent Environment

Effect of pathogens on root disease and length %BRRStructuralFeeder %BRRStructuralFeeder None Rf alone Rf + Pp Effect of pathogens on root disease and length %BRRStructuralFeeder %BRRStructuralFeeder None Rf alone Rf + Pp

Strawberry Root Types Structural roots – 1° & 2 ° well developed cortex. Perennial roots – 2 ° tissues root cortex sloughed off. Feeder roots – 1 ° tissues short-lived, quick cycles. Strawberry Root Types Structural roots – 1° & 2 ° well developed cortex. Perennial roots – 2 ° tissues root cortex sloughed off. Feeder roots – 1 ° tissues short-lived, quick cycles.

Pratylenchus recovery per g root Root type Perennial Structural Feeder Soil Pratylenchus recovery per g root Root type Perennial Structural Feeder Soil

R. fragariae isolation %2mm roots Root typeSpring Harvest Perennial Perennial Structural 3 40 Structural 3 40 Feeder Feeder Pp lesion Pp lesion R. fragariae isolation %2mm roots Root typeSpring Harvest Perennial Perennial Structural 3 40 Structural 3 40 Feeder Feeder Pp lesion Pp lesion 17 73

Nematode-Fungus Interactions Split Root Experiments pot 1 pot 2 Pp Rf None Pp+Rf None Pp None Rf Nematode-Fungus Interactions Split Root Experiments pot 1 pot 2 Pp Rf None Pp+Rf None Pp None Rf

Nematode-Fungus Split Root pot 1 pot 2%BRR Pp Rf14 b None Pp+Rf26 a None Pp12 b None Rf 8 b None Rf 8 b Nematode-Fungus Split Root pot 1 pot 2%BRR Pp Rf14 b None Pp+Rf26 a None Pp12 b None Rf 8 b None Rf 8 b

Nematode-Fungus Interactions Rf and Pp associated with BRR. Additive pathogen interaction. Split root – local interaction. Pp no effect on root exudates or Rf growth in amended media. Nematode-Fungus Interactions Rf and Pp associated with BRR. Additive pathogen interaction. Split root – local interaction. Pp no effect on root exudates or Rf growth in amended media.

Nematode-Fungus Interactions Rf resident on strawberry roots. Secondary growth > Rf infection. Nematode lesions > Rf infection. Pp, 2° growth cause cell death. Rf infects dead cells  healthy. Nematode-Fungus Interactions Rf resident on strawberry roots. Secondary growth > Rf infection. Nematode lesions > Rf infection. Pp, 2° growth cause cell death. Rf infects dead cells  healthy.

Strawberry health Root growth vs. root loss Tolerance to BRR Insect interactions, white grubs and weevils - breeding Strawberry health Root growth vs. root loss Tolerance to BRR Insect interactions, white grubs and weevils - breeding

Management Research Nonhost / antagonistic crops. Effect of fertilizer/pH on BRR. Fungicides - Root drench/dip trt Biological control: PGPR; cvs. IPM – nematode bioassay Management Research Nonhost / antagonistic crops. Effect of fertilizer/pH on BRR. Fungicides - Root drench/dip trt Biological control: PGPR; cvs. IPM – nematode bioassay