Read more about the article Enhanced IPM of Rose Stem Girdler, an Emerging Pest of Pacific Northwest Caneberries

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.

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Read more about the article Attraction and retention of beneficial insects through enhanced plant biodiversity in irrigated vineyards (Vitis vinifera L.)

Attraction and retention of beneficial insects through enhanced plant biodiversity in irrigated vineyards (Vitis vinifera L.)

The success of both integrated pest management and organic production is critically dependent on naturally occurring insect biological control agents. Numerous studies (including some in vineyard systems) have indicated that populations of beneficial insects can be increased by increasing plant diversity (e.g., through cover cropping). Research targeted specifically at the situation in eastern Washington irrigated vineyards is therefore urgently needed.

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Read more about the article Biology and Management of Cutworms in Washington Vineyards

Biology and Management of Cutworms in Washington Vineyards

Cutworms are capable of causing severe damage in vineyards during the early spring months when vines buds and tender shoots are at their most vulnerable. Damage to buds can cause severe crop loss in Washington vineyards, and this study supports the idea that the Cutworm species found on vineyard floors (on weeds, etc.) are a minor component of the fauna that actually damages grapevines. Vineyard sites with a large number of Cutworms on the vineyard floor did not necessarily sustain major bud damage. Conversely, sites with small numbers of Cutworms sometimes sustained major bud damage. This appeared to be related to ground cover presence/absence and/or type, but was also, in view of the rearing data, a consequence of most ground-dwelling species preferring to remain on the ground and not climb up grapevines.

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Read more about the article Investigation of Potential Climatic and Nutritional Causes of Grape Chlorosis

Investigation of Potential Climatic and Nutritional Causes of Grape Chlorosis

Nitrogen levels in grape must that are either too high or too low can cause sensory and economic issues in the production of fine wine. The amount of available nitrogen during fermentation is key to the healthy formation and reproduction of yeast, and completion of the process to dryness. The major yeast strain that dominates healthy alcoholic fermentation, Saccharomyces cerevisiae, typically produces one molecule of urea, glutamate, and proline from the metabolism of the amino arginine.

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Read more about the article Practical applications of stomatal conductance for optimizing irrigation

Practical applications of stomatal conductance for optimizing irrigation

Plant-based estimations of vine water status using tools such as the Scholander-type pressure chambers, which measure leaf water potential, are currently employed by wine grape growers for irrigation scheduling. There is a need; however, for more time-efficient and less intensive methods that would diversify the irrigation scheduling toolkit. A portable leaf porometer measuring stomatal conductance to water vapor provides real-time data on current vine-water status rapidly and through non-destructive means, making it an appealing tool to irrigation scheduling. Three irrigation treatments were applied to a red (Merlot) and white (Chardonnay) cultivars of field-grown grapevines (Vitis vinifera L.) over three growing seasons to evaluate the effectiveness of porometry in determining the extent of water stress. These treatments included high irrigation (~~100% ETc), moderate irrigation (~~50% ETc), and low irrigation (~~25% ETc). From full-bloom through physiological maturity of grape berries, stomatal conductance and mid-day leaf water potential were recorded concurrently from a single leaf in each replication 4 to 6 days after the most recent irrigation.

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