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

Nematode Disease Management Preventative approach best Preventative approach best Sanitation and inspection Sanitation and inspection Rotation with resistance Rotation with resistance Root pruning Root pruning Heat treatment Heat treatment

Nematode Disease Management Sanitation and inspection Sanitation and inspection Host status evaluation : Host status evaluation : Labor-intensive inspection can focus on common susceptible focus on common susceptiblespecies

M. hapla – highly susceptible Acanthus Aconitum Ajuga Astilbe Cimicifuga Coreopsis Clematis Geranium Heliopsis Iris Ligularia Lobelia SalviaStachys Veronica

M. hapla – resistant Achillea Asclepias Aster DigitalisEchinaceaGaillardia IrisLiatris Liriope MonardaPapaver Penstemon Phlox PrimulaRudbeckia

Nematode Disease Management Rotation with resistance 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/potInoculate with 10,000 eggs/pot 2 -6 months growth, bioassay2 -6 months growth, bioassay Evaluate root galling and egg production.Evaluate root galling and egg production.

Effect of Resistance on M. hapla Effect of Resistance on M. hapla Genus Galls/plantGalls/g root Aster 0 0 Coreopsis Lobelia Rudbeckia 0 0

Nematode Disease Management Root pruning 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/potInoculate with 10,000 eggs/pot Three months growth, root prune, two months growthThree months growth, root prune, two months growth Evaluate root galling and egg production.Evaluate root galling and egg production.

Effect of Root Pruning on M. hapla Geranium % Fine roots pruned #Galls #Eggs , , , , , ,

Effect of Root Pruning on M. hapla #Galls/g root#Eggs/g root GenusPruned Not Pruned Not Aconitum Ajuga Anemone ,902 Trollius

Hot Water treatment: M. hapla Large tank submersion Large tank submersion Temp variation +/- 0.5 C Temp variation +/- 0.5 C Cool in C after treatment Cool in C after treatment Astilbe and Hosta: 45 C 60 min; and 47 C for 30 min effective Astilbe and Hosta: 45 C 60 min; and 47 C for 30 min effective 49 C for 30 min - plant death 49 C for 30 min - plant death

Root-Knot Management Preventative approach best Preventative approach best Sanitation and inspection Sanitation and inspection Rotation with resistance Rotation with resistance Root pruning/Heat treatment Root pruning/Heat treatment Plant Breeding/Selection 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) Avid 0.15 EC (abamectin) spider mites: 4 fl oz/100 gal spider mites: 4 fl oz/100 gal leafminer rate: 8 fl oz/100 gal leafminer rate: 8 fl oz/100 gal Diazinon AG oz/3 gal Diazinon AG oz/3 gal Spray to complete coverage Spray to complete coverage

Treatment ppm ai sprays A. fragariae Control Avid Avid Avid Avid P = 0.04 P = 0.04

Ditylenchus per g leaf tissue Treatment ppm ai 1-4 sprays 5-6 Control Avid Avid Diazinon Diazinon

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 DilutionViable (24 hr)(48 hr) control 94 % 76 % 1: : :50 0 0

ZeroTol: Efficacy vs Aphelenchoides A. fragariae per g Anemone leaf Dilution control : :

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 Preventative approach best Sanitation and inspection Sanitation and inspection Reduce overhead watering Reduce overhead watering Insecticide treatments Insecticide treatments Suppression of nematodesSuppression 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 Primarily field-grown problem Pre-plant sampling Pre-plant sampling Rotation - suppressive plants Rotation - suppressive plants

Lesion Nematode Management Preventative approach best Preventative approach best Sanitation and inspection Sanitation and inspection Rotation with suppressive plants Rotation with suppressive plants Rudbeckia hirta; Polynema marigold Rudbeckia hirta; Polynema marigold FumigationFumigation