Nematode Workshop 2nd Morning Session
Signs and symptoms of damage of
nematodes on vegetable and
small fruit crops
George S. Abawi and Beth K. Gugino
Department of Plant Pathology
General 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 include
Galls, stubby roots, excessive branching
Necrotic lesions and general discoloration
Rots
Ditylenchus destructor
Meloidogyne hapla
Most 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 Carrot
Vydate applied at planting
No Vydate at planting
Symptoms of NRKN infection on young and mature carrots
Marketable
0
1
Unmarketable
2
3
4
5
Northern Root-Knot and Lesion
Nematode Damage on Onion
infested
not infested
Symptoms of nematode infestation in an onion field
Meloidogyne hapla
Close-up of rootknot nematode
damage on onion
roots
Thick neck and
reduced bulb size
Galls on 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 plants
Stunted and uneven growth
due to nematode infection
Galls on lettuce root
system
Galls on lettuce with
stained egg sacs
http://starklab.slu.edu/Bio2000/clover
Nodulation on 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
cyst
Lifecycle of Heterodera schachtii
Sugar beet cyst nematode (Heterodera schachtii) damage in
cabbage microplot trial, NYSAES, 1983
Infested with H. schachtii
Uninfested
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