Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology

First Advisor

Bruce H. Bleakley


Two fungal pathogens of wheat which can cause high yield losses are Pyrenophora tritici-repentis and Fusarium graminearum, the causative agents of tan spot and scab of wheat, respectively. Our laboratory attempted to isolate native microorganisms from South Dakota wheat foliage for formulation and application as biological control agents (BCAs) of the causative agents of tan spot and scab of wheat. Native isolates from wheat foliage were tested in vitro for inhibition of the pathogens in plate assays, and then in greenhouse in vivo assays. Isolates 1B-A, 1B-C, 1B-E (identified as Bacillus atrophaeus strains) and 1D-3 (a B. amyloliguifaciens strain) were used in greenhouse trials to determine in vivo inhibition of the pathogens on wheat. Three carriers which were formulated for BCA delivery were sodium alginate/wheat bran pellets, sand/cornmeal mix, and a foliar spray. Greenhouse trials for control of tan spot via BCAs had several individual trials with significantly lower disease ratings on the treated plants than the controls. Greenhouse trials for control of wheat scab via BCAs were inconclusive. Compared to the other carriers, the sand/cornmeal mix appeared to have a superior shelf life and transfer rate of BCAs from carrier to foliage.

Library of Congress Subject Headings

Wheat -- Diseases and pests -- Biological control
Fungal diseases of plants
Wheat speckled leaf blotch




South Dakota State University



Rights Statement

In Copyright