Nematology 100 FINAL EXAM
December 6, 2010 2
hours
(100 points total;
50% of overall grade)
1.
(15 points)
What factors will you consider in developing
crop rotation
strategies for nematode groups with different feeding
habits and life history strategies?
Discuss the utility and constraints of crop rotation for management of the genus
Pratylenchus
and the genus
Globodera.
2.
(10 points)
Compare and contrast the development and characteristics of the feeding sites
incited by
Heterodera
and
Meloidogyne.
3.
(12 points)
Briefly describe the modes of parasitism of the
fungi that are antagonistic to
nematodes. Provide examples where possible.
Suggest approaches for enhancing the abundance and activity of these
fungi in soil.
4.
(16 points)
Based on your knowledge of nematode control, biology, distribution and host
ranges, list control measures that are available and practical for the following
nematode-host associations? (short answers please):
a)
the potato rot nematode,
Ditylenchus destructor, on potato
b)
the foliar nematode,
Aphelenchoides ritzemabosi, on chrysanthemum
c)
the root lesion nematode,
Pratylenchus vulnus, on roses
d)
the pine wood nematode, Bursaphelenchus xylophilus, in pine trees.
5. (12 points)
What strategies are available for management of nematodes in a walnut orchard?
Consider options before planting as well as for orchards with established trees.
6.
(5 points)
|
Using the associated letter(s) in the list on the right, indicate which
descriptors apply to the nematicides below (there may be more than one
answer) |
b)
fumigants
c)
nonfumigants
e)
carbamates
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
7.
(10 points)
As
a member of a technical advisory committee to the California Department of Food
and Agriculture, what actions would you recommend if infestations of the
burrowing nematode,
Radopholus similis, were found in three newly-planted citrus orchards in
southern California?
8.
(10 points)
|
|
Statement |
True (T)
or
False (F) |
|
a |
Mesocriconema xenoplax,
a ring nematode, feeds on roots of woody perennials and is associated
with increased severity of bacterial canker in
peach. |
|
|
b |
Soil
fumigants such as
1,3-Dichloropropene (Telone) move through the air
spaces in soil much faster than through water. |
|
|
c |
Anguina agrostis is sometimes associated
with a bacterial infection of grasses caused by Clavibacter. |
|
|
d |
The potato cyst nematode
recently discovered in Idaho,
Globodera pallida,
is widely distributed in California. |
|
|
e |
Genes conferring resistance in plants to soil nematodes have been found most commonly for
nematodes like
Tylenchorhynchus that are not usually
very damaging to crops. |
|
|
f |
Males of the reniform nematode,
Rotylenchulus reniformis and the citrus
nematode,
Tylenchulus semipenetrans complete several
developmental stages without feeding. |
|
|
g |
Nematophagous fungi
are present in many soils but may be below suppressive levels. |
|
|
h |
Two of the
characters indicating relationships of Nematoda
with other phyla of
animals are that they are segmented and coelomate. |
|
|
i |
Nematode-virus relationships are non-specific and a nematode such as
Longidorus elongatus will vector all strains
of Tobacco Rattle virus.
|
|
|
j |
Migratory endoparasites
like lesion nematodes are often found in the soil and may also feed ectoparasitically. |
|
9.
(10 points)
Design an experiment to test whether two soils have
biological suppressiveness
to nematodes and whether they differ in their levels of suppressiveness.
Explain how you will measure and calculate the levels of suppressiveness.