Nematode Diseases of Perennials
Management
Dr. James A. LaMondia
Plant Pathologist/Nematologist
The Connecticut Agricultural Experiment
Station, Valley Laboratory
Windsor, CT
Perennials: Nematode
Management
• Thresholds lower than annuals
• Fewer chances for control
• Host differences – perennial
roots
Nematode Disease Management
• Preventative approach best
•
•
•
•
Sanitation and inspection
Rotation with resistance
Root pruning
Heat treatment
Nematode Disease Management
Sanitation and inspection
Host status evaluation :
Labor-intensive inspection can
focus on common susceptible
species
M. hapla – highly susceptible
Acanthus
Astilbe
Clematis
Iris
Salvia
Aconitum
Cimicifuga
Geranium
Ligularia
Stachys
Ajuga
Coreopsis
Heliopsis
Lobelia
Veronica
M. hapla – resistant
Achillea
Digitalis
Iris
Monarda
Phlox
Asclepias
Echinacea
Liatris
Papaver
Primula
Aster
Gaillardia
Liriope
Penstemon
Rudbeckia
Nematode Disease Management
Rotation with resistance
Can non-host plants reduce
root-knot populations in soil ?
Greenhouse resistance screen
Rate for galls after two months
98 spp in 85 genera
29 resistant (no galls);
46 susceptible (> 11 galls)
remainder intermediate
Effect of Resistance on
Meloidogyne hapla
• Inoculate with 10,000 eggs/pot
• 2 -6 months growth, bioassay
• Evaluate root galling and egg
production.
Effect of Resistance on M. hapla
Genus Galls/plant Galls/g root
Aster
0
0
Coreopsis 321
18
Lobelia
2576
87
Rudbeckia
0
0
Nematode Disease Management
Root pruning
M. hapla J2 typically infects
at or near root tips. Can
pruning reduce infection?
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.
Effect of Root Pruning on M. hapla
Geranium
% Fine roots pruned #Galls
0
40.3
50
18.7
75
21.4
100
2.9
#Eggs
10,411
2,228
4,460
43
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
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
Root-Knot Management
• Preventative approach best
•
•
•
•
Sanitation and inspection
Rotation with resistance
Root pruning/Heat treatment
Plant Breeding/Selection
Nematodes Infecting Perennials
Meloidogyne hapla - root-knot
Aphelenchoides - foliar nematodes
Ditylenchus - stem/bulb nematodes
Pratylenchus - lesion nematodes
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
Treatment ppm ai sprays A. fragariae
Control
Avid
Avid
Avid
0.0
5.6
5.6
11.2
1
2
1
35.7
6.7
1.9
19.5
Avid
11.2
2
0.0
•
P = 0.04
Ditylenchus per g leaf tissue
Treatment ppm ai 1-4 sprays 5-6
Control
Avid
Avid
Diazinon
0.0
5.6
11.2
5.6
482
257
485
187
215
693
164
2
Diazinon
11.2
226
5
Foliar Nematode Management
with Peroxides
ZeroTol or Oxidate
27% hydrogen peroxide
Evaluate toxicity in vitro
Evaluate efficacy in vivo
ZeroTol: Efficacy vs Aphelenchoides
in vitro evaluation
Dilution
control
1:200
1:100
1:50
Viable (24 hr)
94 %
1
0
0
(48 hr)
76 %
0
0
0
ZeroTol: Efficacy vs Aphelenchoides
A. fragariae per g Anemone leaf
Dilution
1
control
113
1:100
639
1:50
1657
2
113
1208
3988
3
150
872
780
Foliar Nematode Management
with Insecticides/miticides
Pylon: new miticide for ornamentals
21.4% chlorfenapyr
Label for foliar Aphelenchoides
Efficacy similar to Avid
Foliar Nematode Management
• Preventative approach best
• Sanitation and inspection
• Reduce overhead watering
• Insecticide treatments
•Suppression of nematodes
Nematodes Infecting Perennials
Meloidogyne hapla - root-knot
Aphelenchoides - foliar nematodes
Ditylenchus - stem/bulb nematodes
Pratylenchus - lesion nematodes
Lesion Nematode Management
• Primarily field-grown problem
• Pre-plant sampling
• Rotation - suppressive plants
Lesion Nematode Management
• Preventative approach best
• Sanitation and inspection
• Rotation with suppressive plants
Rudbeckia hirta; Polynema marigold
• Fumigation