Cytokinins are a group of plant hormones mediating cell division and
differentiation. Zeatin is a naturally occurring and highly active cytokinin that is rapidly
metabolized in Phaseolus seeds. The metabolites and enzymes mediating the conversion
have been studied extensively. Zeatin metabolic enzymes may be utilized in studying the
regulation of...
Variability in fruit set and yield is a serious problem in Oregon viticulture, particularly with Pinot noir. Climatic variation during the flowering period contributes significantly to this problem by affecting fruit set and cluster weight. Cool wet weather during bloom results in poor set, small clusters, and low yields. Seasons...
In the past ten years, variation in Oregon vineyard yields has come from two main causes: winter injury and inconsistent fruit set. Together these factors have caused significant yield variation in almost every Oregon vineyard. In 1991, a research project was started at Oregon State to develop and evaluate a...
Several effects of xylem discontinuity in Pinot noir and Merlot grape berries were studied. There was a reduction in the amount of apoplastic dye (Eosin Y or azosulfamide) uptake through cut pedicels into soft versus firm berries, suggesting a reduction in maximal xylem flow at that time. Both greenhouse and...
Four year old vines of 18 varieties were cane pruned, trained to a Scott Henry, thinned before veraison, and harvested in October and November 1993. Two of the varieties, Chardonnay and Cabernet Sauvignon, were used as standards. Only four varieties were spur pruned to reduce cropping or cluster size: Dolcetto,...
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Three experiments whose objectives were to investigate cover
crop kill by winter freeze, weed suppression by 'Micah' barley and
other spring cereals, and allelopathic potential of cereal covers
were conducted at the Vegetable Research Farm and in the greenhouse
and growth chamber facilities at OSU in 1989/90. Kill by winter...
Sorbitol-induced osmotic stress (SIOS) to the root was found to be effective in
reducing transpirational water loss in plants during water stress. Mechanisms of SIOS in
stomatal control were investigated in containerized apples (Malus domestica Borkh.
'Gala'/M26) when leaf water potential (Ψw), osmotic potential (Ψs), turgor potential (Ψp),
stomatal conductance...
Dormancy of 'Pinot Noir' grapevines was characterized. Primary buds
required ca 300 cumulative chilling hours (CCH) to initiate the transition from
endodormancy to ecodormancy, which occurred in mid November. Additional
chilling, up to 1000 CCH, improved budbreak. Changes in bud water content
were estimated by gravimetric and spectroscopic methods. Total,...
There have been significant changes in personnel assignments in the OSU Viticulture program during the past year, resulting in shifts in assignments and responsibilities affecting both research and extension in viticulture. Some of these changes are temporary and the current Extension program in viticulture should be considered an interim program....