The efficiencies of wet sieving/sucrose
centrifugation (WS/SC) recovery of Pratylenchus penetrans
(59 %), Paratylenchus sp., (80 %), and Criconemella
xenoplax (66 %) were established. Baermann funnels (BF)
recovered significantly more P. penetrans (p = 0.01) and
significantly less (p = 0.01) C. xenoplax than did WS/SC.
While densities of P....
Verticillium dahliae Kleb. causes a wilt disease of peppermint.
Attempts to control the disease by soil fumigation, crop rotation,
flaming of stubble, and deep plowing have met with only limited success.
Development of resistant varieties through conventional breeding
procedures is difficult because commercial peppermint is male-sterile.
Several strains of commercial...
The fungus Phoma menthae Strasser causes black lesions and
cankers on stems and rhizomes of Mentha piperita L. The purpose
of this thesis was to: 1) study the production of polygalacturonase
(PG) and macerating enzymes (ME) by P. menthae in vivo and in
vitro, 2) study the effects of phenolic...
The objective of this dissertation is to introduce low-cost processing methods for the fabrication of ZnO transparent thin-film transistors (TTFTs). A novel method for depositing ZnO body layers via spin-coating of a zinc nitrate-based spin solution is presented. The processing conditions of spin-coated ZnO are optimized to produce continuous and...
Radial colony growth of three isolates of Gliocladium roseum and three isolates of Bottytis cinerea were measured on 1/4 strength potato dextrose agar amended with concentrations of NaHCO₃ ranging from 0-2% (w/v). Compared to the control, reductions in colony diameter of the B. cinerea isolates ranged from 60-79% and 73-89%...
The in planta growth of three wild type strains of phytopathogenic bacteria and three nonpathogenic mutant strains was studied to determine if mutations eliminating the ability of the mutant strains to cause disease had affected their growth in leaf tissue. The mutant strains were obtained by Tn5 mutagenesis of Pseudomonas...
The effects of fenamiphos on soil and root populations of Pratylenchus penetrans were evaluated in four red raspberry cv. Willamette fields in Northwestern Oregon. Field 1 was a silty clay loam with 53% organic matter (OM). Field 2 and 3 were silty loam soils with 3.25 and 2.55% OM, respectively...
Cephalosporium stripe of wheat (Triticum aestivum),
caused by the soilborne fungus Cephalosporium gramineum,
results in significant yield reductions in dryland winter
wheat crops of the U.S. Pacific Northwest. The
development of resistant cultivars offers the best hope
for disease control. Breeding for resistance is hampered
by the long trial times...
The present studies were conducted to better understand the
etiology, epidemiology and potential control of the Phytophthora
stem root rot as it occurs in apple stool beds.
Symptoms of Phytophthora root and stem rot occurred as early
as May and continued to develop throughout the growing season.
Sunken brown-black lesions...