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Read more about the article Fungal microbiome associated with grapevine trunk diseases in Oregon vineyards

Fungal microbiome associated with grapevine trunk diseases in Oregon vineyards

Grapevine trunk disease (GTD) is a disease complex that consists of the largest group of fungal pathogens causing disease and progressive vine decline. Due to the complex nature of GTD pathogens, understanding the disease as a phenomenon of single species or multiple species infection is always challenging. In addition, the environmental variables play a greater role in the dominance of one species over another. It is important to understand the species that are predominant in a region and their causal role in GTD development so that targeted disease management programs can be developed. In this research project, we study the diversity of GTD pathogens in grapevines of Northern and Southern Oregon; as well as to compare the different disease management practices including vineyard floor management and pruning wound protection.

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Read more about the article Taking proof of concept to wide-scale field use: The OSU high- performance dendrometer

Taking proof of concept to wide-scale field use: The OSU high- performance dendrometer

During the duration of this project researchers refurbished the electronics of all 32 dendrometers and manufactured carbon fiber parts for the new 3 spring design. Two deployments were completed, one at the beginning of the summer and one in mid- summer. The deployment in mid-summer included 3 devices with a new 3-spring design to improve stability over the original 1-spring design from previous years. Researchers worked closely with engineers to implement a data-cleaning algorithm, which removes statistically significant outliers and removes skipping or incongruencies in the data due to bumping or other mechanical disturbances. While effective it is still being improved, live updates are transmitted via 4G LoRa telemetry once every four hours. Measurement data is stored on the SD card at the original 15-minute interval. To further investigate the dendrometer and the 3-spring design, researchers performed off-season experiments in a greenhouse. Researchers continued to develop 4G telemetry capabilities for rapid evaluation of plant water status and device functionality.

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Read more about the article The effect of soil parameters on plant-parasitic nematodes of wine grapes in Washington and Oregon

The effect of soil parameters on plant-parasitic nematodes of wine grapes in Washington and Oregon

Plant parasitic nematodes are costly pests that cause global crop loss of over $100 billion dollars. Previously it was thought that the large populations of ring nematode in Oregon and Northern root-knot nematode in Washington vineyards were caused by differences in soil characteristics. It was found that soil texture had no influence on both types of nematode population growth. It was found that Northern root-knot nematodes that live inside of the roots thrived in acidic (low pH) soil more than alkaline (high pH) soil. It was found that soil pH had no effect on ring nematodes that live outside of the roots. Also generated was a computer model to automate nematode egg counting. These results will help generate parasitism risk maps, helping wine grape growers make better vineyard planting decisions, and will increase the speed with which scientists can identify plant parasitic nematode eggs.

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Read more about the article Risk assessment of nematode-transmitted viruses of small fruit crops in the Pacific Northwest

Risk assessment of nematode-transmitted viruses of small fruit crops in the Pacific Northwest

The Pacific Northwest (PNW) maintains a $840 million small fruit industry susceptible to nepoviruses, which are viruses that are transmitted by dagger nematodes. The association of viruses with nematodes is complicated with many nepoviruses, taxonomic confusion among vector nematodes, and limited data on the ability of Xiphinema spp. populations to vector many of the nepoviruses. Research was conducted to provide an up-to- date assessment of the problem in the region and to develop new molecular tools to improve detection of this disease complex. Over two years, 96 small fruit fields and vineyards were sampled in the PNW. In total 43 vineyard, 24 blueberry, 15 raspberry, 8 blackberry, 5 strawberry and one ribes fields were assessed for dagger nematode and nepoviruses. The highest incidence of dagger nematode was found in grape vines (79 %) followed by raspberry and blueberries. The population densities were 56 and 37 nematodes per 250 cc of soil in grapes and blueberry, respectively. Tomato ringspot virus (ToRSV) was found in three blueberry fields, while, in grape, raspberry and ribes only one field each. Tobacco ringspot virus (TRSV) was found in six vineyards.

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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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