Completed or Ongoing Research
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.
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.
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.
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.
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.
