Signs and symptoms of damage of nematodes on vegetable and small fruit crops Nematode Workshop 2 nd Morning Session 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-knotMeloidogyne hapla Root-lesionPratylenchus penetrans Cyst nematodesHeterodera schachtii Globodera rostochiensis

Northern Root-Knot Nematode (Meloidogyne hapla) on Carrot

No Vydate at planting Vydate applied at planting

Symptoms of NRKN infection on young and mature carrots

Marketable Unmarketable

Northern Root-Knot and Lesion Nematode Damage on Onion infestednot infested

Symptoms 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 plants Stunted and uneven growth due to nematode infection

Galls on lettuce with stained egg sacs Galls on lettuce root system

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 Uninfested Infested 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/cc20 eggs/cc 40 eggs/cc

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

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