Several studies of herbaceous perennials have addressed the effects of environmental factors during and after production, inherent cold hardiness, and post-harvest handling procedures to enhance flowering and growth during establishment. The regrowth of both woody and herbaceous forage plants following establishment is reported to be directly related to reserve-nitrogen content....
Transition matrix models are one of the most widely used tools for assessing population viability. The technique allows inclusion of environmental variability, thereby permitting estimation of probabilistic events, such as extinction. However, few studies use the technique to compare the effects of management treatments on population viability, and fewer still...
The hypothesis that inoculation of transplants with vesicular-arbuscular mycorrhizal (VAM) fungi before planting into saline soils would alleviate salt effects on growth and productivity was tested on lettuce (Lactuca sativa L.) and onion (Allium cepa L.). A secondary hypothesis was that the fungi isolated from a saline soil would be...
Mayweed chamomile (Anthemis cotula L.) is an annual weed in the Asteraceae family that is commonly found in fields of the Pacific Northwest. Acetolactate synthase (ALS)-inhibiting herbicides are frequently used to control a broad spectrum of weed species including mayweed chamomile. Seeds of four biotypes of mayweed chamomile (KJ, KL1,...
The effects of ¹⁵N-labeled fertilizer applied to mature summer-bearing red raspberry (Rubus idaeus L.) plants were measured over two years. Four nitrogen (N) treatments were applied singularly at 0, 40, or 80 kg·ha⁻¹ of N in early spring (budbreak), or split with 40 kg·ha⁻¹ of N (unlabeled) applied at budbreak...
During the last century, fire suppression, grazing, and climate change have caused sagebrush grasslands to be altered in both function and form; juniper and sagebrush dominate the landscape at the expense of herbaceous plants. Management efforts to reduce juniper and sagebrush overstory in order to enhance herbaceous components of the...
Water treatments were applied to young ponderosa pine trees in the Eastern Cascades, Oregon during the 2003 growing season, and shade treatments were applied during the 2003 and 2004 growing seasons to understand how photosynthesis and soil respiration, particularly the root/rhizosphere fraction (R[subscript rrh]), would respond to increased moisture availability...
Lasting, effective solutions to nitrogen (N) loss from container nurseries must
address layers of complexity ranging in scale from whole system nursery management
to gene expression. Group-based On-site Active Learning (GOAL) was developed to
aid nursery managers and related stakeholders (e.g. neighbors, policy makers,
regulating agencies, researchers) in developing a...
Plant form is a compromise between resource gathering, reproduction and
the tolerance to physical demands of the abiotic and biotic environment. In
an agricultural field in addition to the natural factors causing stress, humans
also introduce physical and mechanical stresses, and chemical pesticides
into the environment. Many of these factors...
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4.2 Effectof ultraviolet-B (UVB) radiation on survival of
Italian ryegrass seedlings of a
In 1998, forest vegetation was monitored for ozone injury on permanent plots in two Sierra Nevada national forests in California, at three locations in Mount Rainier National Park in Washington, and at 68 forest health monitoring (FHM) locations throughout Washington, Oregon, and California. This was the first year that extensive...
