Title page for ETD etd-12172008-063243


Type of Document Master's Thesis
Author Johnson, David Alan
URN etd-12172008-063243
Title Infection and development of Ustilago syntherismae in Digitaria ciliaris
Degree Master of Science
Department Plant Pathology
Advisory Committee
Advisor Name Title
Baudoin, Antonius B. A. M. Committee Chair
Derr, Jeffrey F. Committee Member
Kok, Loke T. Committee Member
Keywords
  • Smut fungi
Date of Defense 1990-08-05
Availability restricted
Abstract

Ustilsgo syntherismae (Schwein.) Peck, which causes loose smut of crabgrass, infects its host systemically and destroys seed production. Greenhouse experiments were carried out to investigate the mode of infection, the disease incidence that can be obtained by artificial inoculation and the conditions necessary for optimum infection, cross-infection on southern and smooth crabgrass, and the reasons for the late observance of the disease. U. syntherismse infected southern crabgrass, Digitaria ciliaris (Retz.) Koeler, by both seed-borne and soil-borne teliospore inoculum. Disease incidence was high (84-91%) in some treatments. Higher rates of teliospore application resulted in larger percentages of smutted plants. When infesting the potting mixture, the highest percentages of smutted plants were obtained when infestation and planting were done at the same time. Earlier or later planting resulted in fewer smutted plants. When planting at various depths, greater numbers of smutted plants were obtained when inoculated seed were planted 0.5 to 1.0 cm below the surface versus planting on the surface or at greater depths. The appearance of 50% of infected plants' first panicles (in greenhouse experiments) was delayed by 4.5 weeks compared to the emergence (50%) of first panicles from healthy plants. In cross inoculation experiments, southern and smooth crabgrass plants developed smut only when inoculated with spores collected from large and smooth crabgrass~ respectively.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
[VT] LD5655.V855_1990.J643.pdf 1.67 Mb 00:07:42 00:03:58 00:03:28 00:01:44 00:00:08
[BTD] next to an author's name indicates that all files or directories associated with their ETD are accessible from the Virginia Tech campus network only.

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.