Sugarbeet Cyst Nematode Heterodera schachtii

1. Sugarbeet Cyst Nematode
Heterodera schachtii

2. Scientific name - Heterodera schachtii
Common name - Sugar beet cyst nematode

3. Systematic position
Kingdom: Animalia
Phylum: Nematoda
Class: Secernentea
Order: Tylenchida
Suborder: Hoplolaimina
Superfamily: Hoplolaimoidea
Family: Heteroderidae
Subfamily: Heteroderinae
Genus: Heterodera
Species: schachtii

4. History:
In the early 1800s, "beet fatigue" was used to describe the
decreased sugar beet yields which occurred after repeated planting on
the same field.
At first, this decrease was believed to be the result of nutrient
depletion, but in 1859 the botanist H. Schacht discovered nematode
cysts on the roots of affected plants.
The sugarbeet cyst nematode (Heterodera schachtii )was first
discovered by schacht in 1859 from Germany as the causal organism
of “rubenmudigkiet” or “beet tiredness”.
Later named as Heterodera schachtii by Schmidt in 1871.

5. Host range:
It can infect more than 200 plant species, including sugarbeet,
redish, broccoli,cabbage.
It can also survive on weeds.
Distribution:
Widely distributed in all sugar beet growing areas of the world.
Today, SBCN is present in forty different countries and seventeen
states in the United States, including Washington, Oregon, Utah, and
Idaho.

6. Spread:
SBCN is a soilborne pest, so anything that can
move soil will move the nematode.
Cysts can be spread by machinery, animals, water
and tare soil from harvested beets.
In the soil profile, cysts can be found from the
surface to 24 inches deep, but the highest numbers
are found in the root zone (2 to 10 inches soil
depth).

7. Diagnostic features:
Mature female and cyst:
Lemon shape with a short neck and terminal cone (vulval), turning
into a hard wall cyst, brown to black in colour, vulva terminal, anus
dorsally subterminal, most eggs retained in the body,some may be
laid in gelationus matrix.

8. Male
•About 1 mm, vermiform, stylet and oesophagus well-
developed, tail end twisted, without bursa, spicules robust,
gubernaculum simple.
Second-stage juvenile
•Body slender, about 400-500 µm long, cephalic
sclerotisation and stylet robust than in root-knot nematode,
oesophageal glands overlap intestine ventrally, tail with a
prominent hyaline portion

9. Life Cycle and Survival
Sedentary endoparasite, The nematode survives in the soil as cysts
that contain eggs and juveniles.
Under favorable conditions — warm temperatures (70 to 81 degrees
F) and sufficient soil moisture — and the presence of root exudate
from hosts, second-stage-juveniles hatch from eggs, enter the root
tissue, and move to cortical tissues where they feed.

10. After development to third (sausage-shaped) and fourth juvenile stages, adults are
produced.
Adult males are thread-like in appearance. The adult males stop feeding and migrate from
roots to the soil.
While mature swollen females remain attached to the roots as a sedentary endo-parasite
with the posterior end outside the root

11. 200 to 300 eggs are produced by one female. Most of the eggs remain inside the
female and some are laid outside the body in a mucoid mass.
When eggs are fully developed, the female dies and its body hardens to form a
brown or yellow-brown cyst that protects the eggs.
The life cycle period varies from 4-6 weeks, depending on soil temperature.
cysts can survive over 12 years under fallow conditions.

12. Life cycle of heterodera schactii

13. Symptoms:
Fields may be uniformly infested or may have localized areas of
infestations.
 Circular to oval spots where poor plant stands and growth are
observed.

14. The pathogen can attack plants of any age, and seedlings or
young
beets may be killed , resulting in reduced stands.
Young plants infected by the disease have elongated petioles
and remain stunted until harvest.
 Leaves of severely affected plant additionally wilt and have
pronounced yellowing.

15. Management:
Sanitation:tare soil should not be dumped back into fields.
Plant SBCN tolerant cultivars which are available, but be aware of
their susceptibility to other diseases, including Cercospora and
Rhizoctonia root rot.
 Rotation with non-host crops, including wheat, barley, corn, bean,
potato and alfalfa.
Three- to four-year rotation is needed in heavily infested fields;
rotations with non-host may reduce initial SBCN population by 40-60
percent in a year.

16. .
Plant trap crops which attract SBCN, but do not allow them to develop and
reproduce. Some SBCN-tolerant cultivars of oil seed radish (Defender, Image and
Colonel) and mustard are effective.
 Early planting when soil temperatures are not favorable (< 59 degrees F) for infection
by SBCN.
Control weeds that are hosts for SBCN in sugar beet and rotation crops.
Avoid returning tare soil with SBCN to fields in which sugar beet is grown.
 Some nematicides may be effective, but are typically difficult to apply and may be
uneconomical. Biological seed treatment which utilize spores of Pasteuria nishizawae may
help to manage SBCN on tolerant sugarbeet varieties.

17. Thank you