NEMATOLOGY 100   -  FINAL EXAM      Name:


(50% of overall grade)
December 18, 1993        2 hours

 1.  (15 points)
     Discuss the life cycle, mode of parasitism and survival of
     the rice root nematode, Hirschmanniella oryzae.  A related
     species, H. belli, occurs in California; what factors govern
     its importance in rice production?



 2.  (15 points)
     Briefly describe the modes of parasitism of the fungi that are
     antagonistic to nematodes.  Provide examples where possible.



 3.  (15 points)
     What strategies are available for management of nematodes in
     perennial crops?  Consider options before planting and for
     established orchards.



 4.  (10 points)
     List factors to be considered when selecting cover crops for
     nematode management.



 5.  (10 points)
     A tomato variety resistant to the soil fungus Fusarium
     oxysporum succumbs to fusarium wilt when planted in certain
     fields.  The incidence of the disease is negligible when the
     fields are treated with a broad spectrum soil fumigant.  In
     other fields the variety performs well and retains its
     resistance.  Outline the treatments you will use to determine
     the cause of resistance failure.  Explain your treatment
     selection.



 6.  (10 points)
     Belonolaimus longicaudatus, the sting nematode, is an
     important parasites of cotton and soybeans in the southeastern
     U.S.  How are plants damaged?  Assess the potential for this
     nematode becoming a significant problem in California
     agriculture.



 7.  (15 points)
     Briefly discuss the economic importance, distribution and host
     range of the burrowing nematode, Radopholus similis.  Outline
     a control program for a crop on which it is a major pest.



 8.  (10 points)
     Associate code letters for the organisms on the right with the
     descriptors on the left.  (Some letters may be used several
     times, others may not be used at all.  Examples for each
     descriptor may range from none to several, provide all that
     apply.)

     _________1. Animal parasite       a) Caenorhabditis elegans
                                       b) Mesocriconema xenoplax
     _________2. Fungus feeder         c) Xiphinema californicum
                                       d) Ditylenchus destructor
     _________3. Predator              e) Acrobeloides bodenheimeri
                                       f) Mononchus papillatus
     _________4. Bacterial feeder      g) Heterodera glycines
                                       h) Globodera rostochiensis
     _________5. Host-mediated egg     i) Trichinella spiralis
                  hatch                j) Pseudomonas solanacearum
     _________6. Virus transmission    k) Rotylenchulus reniformis
                                       l) Seinura demani
     _________7. A-rated pest (CDFA)   m) Ascaris suum

     _________8. Sub-order Aphelenchina

     _________9. Nematode/bacterium interaction

     _________10. Seed galls