Signs and symptoms of damage of nematodes on vegetable and

small fruit crops

Nematode Workshop 2nd Morning Session

George S. Abawi and Beth K. Gugino

Department of Plant Pathology

General field symptoms includeGeneral field symptoms include

Reduced growth

Yellowing of foliage (nutrient deficiency-like)

Excessive wilting in hot or dry weather

Reduced yields

Poor quality produce Symptom severity

are nematode density dependent.

Accompanying root symptoms includeAccompanying root symptoms include

Galls, stubby roots, excessive branching

Necrotic lesions and general discoloration

Rots

Ditylenchus destructor Meloidogyne hapla

Most important nematodes on vegetables in the NortheastMost important nematodes on vegetables in the Northeast

Northern root-knot Meloidogyne hapla

Root-lesion Pratylenchus penetrans

Cyst nematodes Heterodera schachtii

Globodera rostochiensis

Northern Root-Knot Nematode (Meloidogyne hapla) on CarrotNorthern Root-Knot Nematode (Meloidogyne hapla) on Carrot

No Vydate at plantingNo Vydate at planting

Vydate applied at plantingVydate applied at planting

Symptoms of NRKN infection on young and mature carrots

MarketableMarketable UnmarketableUnmarketable

0 1 2 3 4 5

Northern Root-Knot and Lesion Nematode Damage on Onion

Northern Root-Knot and Lesion Nematode Damage on Onion

infested not infested

Symptoms of nematode infestation in an onion fieldSymptoms of nematode infestation in an onion field

Meloidogyne hapla

Galls on roots

Thick neck and reduced bulb size

Close-up of root-knot nematode damage on onion roots

Root-lesion nematode (Pratylenchus penetrans) in an onion root

eggs

juveniles

Pratylenchus penetrans

Lesions on soybean root

Northern Root-Knot Nematode (Meloidogyne hapla) on Lettuce

Healthy lettuce plantsStunted and uneven growth due to nematode infection

Galls on lettuce with stained egg sacs

Galls on lettuce root system

Nodulation on cloverhttp://starklab.slu.edu/Bio2000/clover

Symptoms of a heavy nematode infestation in a potato field

Golden Potato Cyst Nematode (Globodera rostochiensis)

Photo credit: Christopher Hogger, Swiss Federal Research Station for Agroecology and Agriculture, Bugwood.org

Lesions from P. penetrans infection on potato tubers

Lesions from P. penetrans infection

on potato roots

Root-knot

Potato early dying disease (PED)Potato Early Dying Disease (PED)

(Pratylenchus penetrans + Verticillium dahliae)

No galls develop on the primary roots

Northern Root-Knot Nematode (Meloidogyne hapla) galls on the fine potato roots

Severe damage to potato by M. hapla

Sugar beet cyst nematode (Heterodera schachtii) damage in a beet field

Sugar beet cyst nematode on beet

seedling roots

female cystfemale cyst

Lifecycle of Heterodera schachtii

Sugar beet cyst nematode (Heterodera schachtii) damage in cabbage microplot trial, NYSAES, 1983

UninfestedInfested with H. schachtii

Roots of cabbage grown in soil heavily infested with H. schachtii (right) vs. uninfested soil (left)

Small loose cabbage head

from plant grown in soil

heavily infested with H. schachtii

(right) vs. uninfested soil

(left)

Yield of cabbage grown in heavy textured soil infested with increasing densities of sugar beet cyst nematode (Heterodera schachtii), NYSAES, 1983

Fumigated 10 eggs/cc 20 eggs/cc 40 eggs/cc

Tomato roots grown in uninfested (left) and soil infested (right) with Meloidogyne hapla

UF factsheet

UF factsheet

Root-knot nematode (Meloidogyne spp.)

damage on bean in the field and severe galling on

the roots.

Stubby root nematode (Paratrichadorus christiei) damage

on corn roots