A seed maturation study was conducted to determine the earliest
date seed of subterranean clover (Trifolium subterraneum L.) may be
safely harvested without reduction in yield or seed quality. In 1981
and 1982, seed and bur weight, seed and bur moisture content, germination and seedling vigor were studied to determine...
A parasitic wasp, Trioxys pallidus Haliday
(Hymenoptera: Aphidiidae) was imported from Europe and
initially released against the filbert aphid Mvzocallis
coryli (Goetze) in hazelnut (filbert) orchards of the
Willamette Valley, Oregon beginning in 1984. In the
present study, I investigated the establishment rates of
this parasitoid. A total of 13...
Montane meadows in the western Cascades of Oregon occupy approximately 5% of the landscape, but contribute greatly to the region's biodiversity. Western Cascades meadows are dynamic parts of the landscape and have contracted by over 50% in the past two hundred years in the HJ Andrews Experimental Forest (hereafter Andrews...
Knowledge of post-dispersal seed fates and other regeneration characteristics is
crucial for predicting abundances and distributions of populations and, ultimately,
community species composition and diversity. Seed fate studies, however, are rare
primarily due to the difficulty of determining seed fates and causes of mortality.
This thesis investigated post-dispersal seed fates...
Relay strip-cropping combines two vegetation management tactics, under-sowing and strip-management. In this study conducted from 1994 though 1997, a cover crop seed-mixture containing oats (Avena sativa L. var. "Monida"), common vetch (Vicia sativa L.), red clover (Trifolium pratense L.), annual ryegrass (Lolium multflorum Lam.), and buckwheat (Fagopyrum esculentum Moench) was...
Drosophila suzukii (Diptera: Drosophilidae), a pest of thin-skinned fruits, has been detected worldwide recently, with new locations of establishment determined annually since it first became a concern on continental North America in 2008. Drosophila suzukii females are different from most other drosophilids as being one of two known species capable...
Halyomorpha halys (brown marmorated stink bug, Hemiptera: Pentatomidae), an invasive insect pest, has established populations in the Willamette Valley of Oregon. Halyomorpha halys is a potential pest of many specialty crops in the Willamette Valley, including hazelnuts (Corylus avellana L.). The objectives of this study were to 1) characterize the...
Over one third of the earth’s land surface has been modified to some extent for agricultural purposes. The large global footprint of agriculture, combined with the knowledge that existing reserve networks are likely insufficient for long-term conservation of native biodiversity, has necessitated that agricultural systems contribute to conservation of native...
