Evaluating Commercially Available Technologies for Weed Management in Blueberries: Saturated Steam and Rotary Brush

Washington and Oregon account for 85% of national raspberry production and 15% of worldwide production. Growers from Washington and Oregon harvest over 80 million pounds of raspberries on about 12,000 acres. Tomato ringspot virus (ToRSV) continues to be a problem in raspberry production in the Willamette Valley in Oregon, and in southern Washington. The predominant mode of spread of ToRSV is via the nematode vector Xiphinema americanum, also known as “Dagger” nematodes. Methyl bromide is often a method of choice for managing ToRSV and other nematode-borne plant viruses because it kills the nematode vectors. However, ToRSV often reappears within 3-4 years of fumigation with methyl bromide.

Continue ReadingEvaluating Commercially Available Technologies for Weed Management in Blueberries: Saturated Steam and Rotary Brush

Detection and monitoring of Tomato Ringspot Virus in red raspberry and Xiphinema americanum.

Washington and Oregon account for 85% of national raspberry production and 15% of worldwide production. Growers from Washington and Oregon harvest over 80 million pounds of raspberries on about 12,000 acres. Tomato ringspot virus (ToRSV) continues to be a problem in raspberry production in the Willamette Valley in Oregon, and in southern Washington. The predominant mode of spread of ToRSV is via the nematode vector Xiphinema americanum, also known as “Dagger” nematodes. Methyl bromide is often a method of choice for managing ToRSV and other nematode-borne plant viruses because it kills the nematode vectors. However, ToRSV often reappears within 3-4 years of fumigation with methyl bromide.

Continue ReadingDetection and monitoring of Tomato Ringspot Virus in red raspberry and Xiphinema americanum.

Enhanced IPM of Rose Stem Girdler, an Emerging Pest of Pacific Northwest Caneberries

Rose stem girdler (RSG) is an invasive beetle pest of caneberry crops that is becoming increasingly problematic for Pacific Northwest (PNW) growers. It has progressively become naturalized throughout the northern Willamette Valley northward to the south Puget Sound region throughout the 2000s-present due to abundant wild bramble hosts. Grower reports of damage to crops has been variable, but with incidental claims of up to ~70% crop loss in a given year due to cane girdling by the beetle’s larvae. Control has been difficult and inefficient due to narrow windows of time for effective control (after adults emerge from canes, but before egg-laying begins 7 days later), and the lack of region-specific information to predict emergence and longevity of egg-laying activity. Our project objectives were: 1) to refine determinants of risk to PNW caneberry plantings from RSG through coordinated regional pest surveys, 2) to develop an enhanced integrated pest management (IPM) program with refined information on RSG detection methods, life cycle, and development of a pest management prediction model, and 3) to investigate biocontrol potential of a parasitoid wasp that may mitigate RSG’s viability and play a role in future IPM programs.

Continue ReadingEnhanced IPM of Rose Stem Girdler, an Emerging Pest of Pacific Northwest Caneberries

Development of Aphid Resistance Resources in Black Raspberry

Black raspberry is a well-known Pacific Northwest specialty crop with unique flavor and nutritional attributes, but also unique vulnerabilities. A prominent threat facing the crop is the aphid-vectored Black Raspberry Necrosis Virus. Natural genetic resistance to aphids has been identified in black raspberry germplasm in Maine (ME), Michigan (MI), and Ontario (ON), Canada. In a collaboration between OSU and USDA-ARS researchers, genetic linkage mapping found three separate but linked genetic loci on Rubus Linkage Group 6 (RLG 6). Attempts to target these loci with genetic markers could not clearly distinguish the three from each other.

Continue ReadingDevelopment of Aphid Resistance Resources in Black Raspberry

Diversity of Pseudomonas syringae and diagnosis and management of bacterial canker on blueberry

Bacterial canker caused by the bacterial pathogen Pseudomonas syringae is characterized by killed buds and stems. The disease can be severe when environmental conditions support growth and infection of tissues in the fall and spring. The disease is especially damaging to young succulent plants. Copper is sprayed onto plants to control the growth of the pathogen and the development of bacterial canker. P. syringae actually refers to a complex group of pathogens, with individual members that have either a wide host range or narrow host range. Surprisingly, little was known about P. syringae causing bacterial canker on blueberry. It was not known if only a single type of P. syringae with a narrow host range caused bacterial canker or if multiple types of the pathogen complex caused bacterial canker. P. syringae can use many traits to cause plant diseases, such as the production of plant toxins or the ability to nucleate ice formation.

Continue ReadingDiversity of Pseudomonas syringae and diagnosis and management of bacterial canker on blueberry