NEMATOLOGY 100 Name:
December 11, 1999 2 hours
(100 points total; 50 % of overall grade)
1. (15 points)
Compare life-history strategies that contribute to the success of root knot and cyst nematodes in annual crop agriculture. How do these strategies affect your design of crop rotation programs to manage the nematodes?
2. (15 points)
You are 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, was found in three newly-planted citrus orchards in southern California?
3. (15 points)
Describe the biology and life cycle of the pine wood nematode. In what taxonomic group is this nematode classified? (You can provide family, superfamily or sub-order)
True (T) or False (F)
a. Anguina agrostis is sometimes associated with a bacterial infection of
grasses caused by Clavibacter.
b. Nematode-virus relationships are non-specific and a nematode such as
Longidorus elongatus will vector all strains of Tobacco Rattle virus.
c. Males of Rotylenchulus reniformis and Tylenchulus semipenetrans complete several developmental stages without feeding.
d. Species of Helicotylenchus behave as migratory endoparasites on some hosts.
e. Mesocriconema xenoplax feeds on roots of woody perennials and is associated
with increased severity of bacterial canker in peach.
f. Soil fumigants such as 1,3-Dichloropropene (Telone) move through the air
spaces in soil much faster than through water.
Globodera rostochiensis is widely distributed in California.
h. Ditylenchus dipsaci is a root tip feeder.
5. (20 points)
Based on your knowledge of nematode biology, available management tactics, host ranges, etc., what control measures are available and practical for:
Pratylenchus vulnus on walnuts
Meloidogyne incognita on tomato
Heterodera glycines on soybeans
Xiphinema index on grape
Aphelenchoides fragariae on chrysanthemums
6. (12 points)
Indicate which of the following nematicides are:
none of the above
(note there may be more than one answer in each case)
(ii) Temik 10G
(v) Methyl bromide
7. (15 points)
Discuss the modes of predation and parasitism of fungal antagonists of nematodes. Provide examples of the fungi and explanatory drawings where possible.