Read more about the article Reducing leaf chlorosis of ‘Concord’ vines: Effects of FeEDDHA and rootstocks

Reducing leaf chlorosis of ‘Concord’ vines: Effects of FeEDDHA and rootstocks

‘Concord’ vineyards in central Washington are plagued by a leaf chlorosis problem that occurs around bloom. It significantly reduces vine size, vine uniformity, and productivity, and even causes vine death. Chlorotic leaves from WA vineyards have significantly lower active Iron (Fe) compared with green leaves whereas total leaf Fe is the same or even higher; 2) high soil pH induces leaf chlorosis in Concord vines; 3) leaf active Fe content is a better indicator of Concord vine Fe status than total Fe. This project is a continuation of the work. The objectives were to determine the effects of FeEDDHA (a chelated form of Fe) and different rootstocks on reducing leaf chlorosis. A field trial in central WA over 3 years clearly showed that FeEDDHA application significantly decreased the degree of canopy leaf chlorosis; and that Concord vines grafted onto 3309, 5C and 110R had better growth, higher photosynthesis, and less chlorosis than the own-rooted vines at high soil pH (7.6).

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Read more about the article Optimizing Nutrient Management for Organically Grown Blueberries East of the Cascade Range

Optimizing Nutrient Management for Organically Grown Blueberries East of the Cascade Range

Northern highbush blueberry (Vaccinium corymbosum) production east of the Cascade Range is an important contributor to the national supply of organic blueberries. However, native soil conditions are alkaline, have high free calcium content, and low in organic matter. Although growers amend soils to lower pH and provide organic matter, these soil characteristics influence nutrient cycling and availability. Growers need data-driven guidelines on how to optimize nutrient management for their unique growing conditions, but few studies have been conducted in this important region. This project addressed that need with an emphasis on organic nitrogen fertility practices by evaluating the effects of commercially available organic nitrogen fertilizer sources applied at low, medium, and high rates on blueberry yield, fruit quality, and various plant and soil variables. Organic fertilizer nitrogen mineralization dynamics were also characterized via a laboratory incubation study at different temperatures.

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Read more about the article Trials of Advanced Raspberry selections to evaluate suitability for IQF processing and to promote adoption

Trials of Advanced Raspberry selections to evaluate suitability for IQF processing and to promote adoption

A new cultivar, ‘Cascade Premier’, and an advanced selection, ‘WSU 2188’, were compared with industry standard cultivars under commercial production and processing conditions. The cultivars were evaluated for Individually Quick Frozen (IQF) processing quality, yield, pest tolerance, disease susceptibility and winter hardiness. ‘Cascade Premier’ was compared with adjacent, similarly managed ‘WakeHaven®’. ‘Cascade Premier’ yields were limited at one location by cane botrytis, which reduced the numbers of fruiting laterals. ‘Cascade Premier’ generally produced fewer, but larger fruits than WakeHaven®. Under warm conditions favoring rapid ripening, ‘Cascade Premier’ produced IQF quality fruit when harvest intervals were short enough (less than 3 days), but became too soft for IQF processing at longer harvest intervals.

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Read more about the article Developing a Spray-Induced Gene Silencing (SIGS) method for the control of Grape Powdery Mildew (Erysiphe necator)

Developing a Spray-Induced Gene Silencing (SIGS) method for the control of Grape Powdery Mildew (Erysiphe necator)

Powdery Mildew development in vineyards in the Pacific Northwest is one of the greatest impacts to grape and wine quality and the economic health of a grape grower is severely impacted by the number of sprays required to control the disease or loss in fruit sales if a severe infection develops. In high wine-producing regions, Grape Powdery Mildew (GPM) accounts for 75% of total pesticide use applications. If the grapevines are not properly treated until harvest, the presence of GPM in harvest grape clusters substantially depreciates the value of the entire crop. This project aims to develop a methodology to turn off specific grapevine genes (susceptibility genes [MLO]) and Powdery Mildew-related genes essential for the pathogen’s life cycle.

Continue ReadingDeveloping a Spray-Induced Gene Silencing (SIGS) method for the control of Grape Powdery Mildew (Erysiphe necator)
Read more about the article Inducement of malolactic fermentation using Lactobacillus plantarum in musts and wines from the Pacific Northwest.

Inducement of malolactic fermentation using Lactobacillus plantarum in musts and wines from the Pacific Northwest.

The completion of both alcoholic and malolactic fermentation (MLF) in red wine are essential to the quality and stability of red wine and to its commercial success in the market. In this study, alcoholic and malolactic fermentations were induced in low and high nitrogen-containing Cabernet Sauvignon musts by adding both yeast (Saccharomyces cerevisiae) and bacteria (Oenococcus oeni or Lactobacillus plantarum) at the same time. While O. oeni was able to complete MLF in the high nitrogen fermentations, only one of the three strains of Lb. plantarum was able to convert the majority of malic acid to lactic acid (<0.5 g/L residual malic acid). Under low nitrogen conditions, neither alcoholic or malolactic fermentation finished in any of the wines. Subsequent fermentations using a synthetic grape juice medium yielded poor growth of bacteria whether inoculated subsequently or concurrently with S. cerevisiae. Additional studies with Lb. plantarum are required to fully evaluate their potential usefulness to Pacific Northwest winemakers.

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