Graduate Thesis Or Dissertation
 

Evaluating the effectiveness of commonly used herbaceous weed control regimes in a Pacific Northwest conifer plantation

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/ht24wm578

Descriptions

Attribute NameValues
Creator
Abstract
  • Early in the establishment of Pacific Northwest conifer plantations, herbaceous weeds often decrease seedling growth through competition for soil moisture during the dry summer months. Critical period studies have reported that reductions in competitive weed cover are necessary during the initial years of establishment to avoid reductions in seedling growth. Six herbicide treatment regimes commonly applied over the first two years of plantation establishment were studied in a randomized block design to understand Douglas-fir seedling growth response. First season results demonstrate that seedling growth was improved when competing vegetation cover was reduced through the regimes examined. Volume growth increased from 5 cm3 in the untreated control to greater than 20 cm3 when total weed cover was reduced below 10%. Multiple vegetation surveys within a single season revealed that reductions in total vegetation cover were associated with the treatments and tracked distinct changes to the species composition of the weed communities that remained in these plots. Soil moisture and xylem water potential were intensively measured and demonstrated that the vegetation management regimes utilized in this study improved growing conditions. While all herbicide regimes in the experiment increased seedling growth relative to the untreated control, the incorporation of a site preparation spray and a spring release was the most effective treatment. This regime had a profound impact on seedling growth, vegetation cover, soil moisture, and xylem water potential during the initial season of the critical period.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Language
File Format
File Extent
  • 540278 bytes
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details Dinger_thesis.pdf 2017-08-01 Public Download