In This Issue  

• Project Update 
• What's Buggin' Me Now?? 
• Satellite Research Station 
• Growers' Breakfast Meetings  
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• Insect and Disease Identification 
• At the last raspberry breakfast meeting, growers expressed an interest in publications that can assist them in insect and disease identification. The final product of the Nooksack IPM Project will be a manual which consolidates much existing material into one reference. Until that publication is complete, there are a few key publications which you may find useful. They can all be made available by contacting Whatcom County Cooperative Extension in Bellingham at 676-6736. They are listed below:  
• • Compendium of Raspberry and Blackberry Diseases and Insects - APS Press  
• • Small Fruit Pests, Biology,  
  Diagnosis and Management - WSU EB1388  
• • Caterpillar Pests of Raspberry in the Lower Fraser Valley, B.C. - Ag Canada 

Project Update  

IPM Mentoring Project   

An important focus of the Nooksack IPM Project this year is to work closely with a few raspberry and apple growers (mentors) by regularly helping them scout one of their fields for insects and diseases. Selected fields are systematically scouted every two weeks using sampling tools and methods which are efficient to use and provide growers with information that can assist them in the need for and timing of pesticide applications. Here is what we have learned so far in raspberries:  

• Mid-April disease ratings showed a significant range of over- wintering infection levels of spur blight and cane botrytis in the three fields being sampled. Seeing this variation in disease pressure was a real eye-opener for growers.  

• We have been using a sampling procedure, based on research from Agriculture Canada, to determine whether overwintering oblique banded leafrollers require treatment. We examine a total of 100 hills in each field (20 hills/site at 5 sites/field) for leafrolling and the presence of leafrollers. We examine 5 lateral shoot tips per hill on 20 hills per site. If one shoot tip is infested, that hill is recorded as infested and we move on examining 20 hills at each of 5 sites in the field. The suggested action or treatment threshold is 10% infested hills. The highest we have seen in any field is 2% and no sprays for OBLR have been necessary.  

• We use a beating tray to monitor various pest and beneficial insects which reside in the canopy. Ten tray samples are taken at each of 5 sites in a field and the results are recorded for each site. This sampling method has identified fields which are infested with western raspberry fruitworm and those which are clean. Having this knowledge allows the grower to apply a timely spray and reduce the risk of fruit contamination or, in a clean field, avoid an otherwise unnecessary spray which is money in the bank.  

• We use a subjective rating system(0-5) to evaluate and record yellow rust (aecia) incidence at several sites in a field. Field records again show quite a bit of difference between fields regarding disease incidence and timing and need for treatment. In one field, yellow rust aecia increased significantly between late April and mid-May, which supported the decision to apply a fungicide.  

In summary, growers are realizing the benefit of spending an hour or so every two weeks to learn more about what is and what is not happening in their fields. We'll keep you posted. 

Research 

Topics 

On-Farm Research   

Thanks to an initial inquiry from Whatcom Farmers Co-Op regarding timing of Sulforix applications in the early spring, we initiated an on-farm research project with Best Sulfur Products and two cooperating growers, Tena Ondeck and Randy Honcoop. The purpose of this experiment was to relate different timing of Sulforix treatments to phytotoxicity and disease suppression. Treatments included:  

• an untreated check;  

• standard rate and timing (3 gal Sulforix /100 gal. water/acre) at bud break;  

• reduced rate and delayed timing (1.5 gal Sulforix/100gal. water/acre) at 1.5 inches shoot growth; and  

• a combination of these two Sulforix treatments.  

Each treatment was replicated three times at each farm. The initial spray went on later than most commercial applications (3/21-22) and the second spray was applied on 4/17 when shoot length at the wire averaged 2-3". Preliminary results are quite interesting.  

The later application initially caused some leaf distortion and burning of leaf margins but these symptoms were rapidly outgrown. Of particular interest is a significant reduction in yellow rust aecia in plots receiving the late and combined sprays when compared to the standard timing and untreated check.  

Much thanks to Randy and Tena for their work in evaluating these experiments and to Pete Bristow (WSU plant pathologist) who is helping us quantify the effects of these treatments on yellow rust development and fruiting lateral shoot growth as well. 

Raspberry Growers 

Raspberry Breakfast Meetings/IPM Forum   

Our next IPM breakfast meeting is scheduled for Wednesday, June 4th at Dutch Mothers in Lynden from 6:30 am to 8:00 a.m. Come learn more about the IPM mentoring program and useful scouting tips for the next few weeks as we rapidly approach harvest. Our contingent of researchers from the satellite station will give you an update on their activities as well. 

What's Buggin' Me Now?? 

Western Raspberry Fruitworm 

Byturus bakeri 

Black Vine Weevil

Otiorhynchus sulcatus 

Western Raspberry Fruitworm   

As mentioned above in the IPM Mentoring discussion, some fields were treated for this insect in mid to late May prior to bloom. This is the optimum timing to control this insect because adult beetles are controlled before they begin laying eggs in flowers. These eggs hatch and developing larvae can bore into and contaminate fruit. Clean up sprays applied just prior to harvest probably provide some level of control of this insect but is definitely not the preferred timing for infested fields. This insect does not appear to be widespread. Scouting this season indicates that fruitworm is more common in fields in the Northwood area and South of Everson near the Nooksack River.  

Black Vine Weevil   

Adult BVW usually start to emerge from the soil in late May. Remember that not all fields are infested with this insect. Since BVW is not able to fly, it takes some time for it to migrate into new fields and spread within a field. Use a beating tray to sample your field for weevils. The trays are available at our cost of $25 each. Contact Geoff Menzies at 384-9135 if you would like to purchase a tray or learn more about using one. 

Spider Mites

Twospotted Tetranychus urticae Koch  

Research 

Topics 

Spider Mites  

Spider mite populations have been low so far in most fields, but both twospotted and yellow mites are present in many fields. Predator mites are active in many fields also. Look at older leaves at wire height for signs of mite feeding. Twospotted mite feeding causes a white stippling on the upper leaf surface and yellow mite feeding causes a more diffuse yellowish discoloration on the upper leaf surface. If you see this type of damage, look closer by collecting leaves at several sites in a field. A 10X hand lens is very helpful for estimating mite density and determining relative numbers of mite eggs and activity of predator mites. A population of 5-10 spider mites per leaflet with numerous eggs and few predators usually justifies control at this time of the year. In most cases, mite populations do not increase to damaging levels until mid or late harvest.  

Satellite Research Station (supplied by Patrik Hertzog)   

Washington State University Satellite Station in Lynden is buzzing with the activity of our various projects for this year. We have gathered some promising preliminary results from our first pesticide trials for the clay-colored weevil using the basal spray technique. Both Brigade and an experimental chemical with registration potential appear to offer good control of the weevil. However, our data suggests that some recovery from the sprays or possible weevil migration may have occurred. Katie Lauby, our WWU graduate, is currently documenting the biology of clay-colored weevil through colonies that she is helping to rear, while our Russian guest Natasha Bassangova is using pitfall traps to search for natural predators of root weevils. Katie and Natasha are also monitoring the egg production of our weevil colony for the purpose of timing sprays prior to egg deposition. We have all been hitting the dirt lately to keep close tabs on when we can expect the first black vine weevils to begin emerging. We are seeing plenty of larvae and more and more pupae by the day, which suggests that they should begin emerging in the next week or two. At that point, we will gather colonies of BVW to monitor egg production to help time basal sprays in our experimental plots. In addition to the expanded root weevil research this year, we will be expanding our spider mite research. Malika Bonfour, our spider mite specialist, will be joining us June 1st to help oversee research in this area. I, Patrik Hertzog, am keeping busy coordinating these and other projects.  

We are currently seeking weevil and spider mite fields; if you have had problems with these critters in the past and would like to partake in WSU research, please call the station at (360) 354-5944. 

Apple 

Growers  

Apple Breakfast Meetings/IPM Forum   

The next breakfast meeting for apple growers is scheduled for 7:00 am on Tuesday, June 3rd at Dutch Mothers Restaurant in Lynden. Come and compare notes on leafhopper management and codling moth degree day information. It's also time to start thinking about mite sampling.  

Codling Moth Program  

Temperature and codling moth trap catch data is being collected weekly at several area orchards. This information is made available on Monday mornings through a phone recording which you can reach at 715-8241. It is the combination of site-specific trap catch data and heat accumulation which determine the need for and timing of pesticide applications to control codling moth(CM). This predictive, decision-making tool for managing this key apple pest is described in WSU Extension Bulletin 1072.  

As of Friday, May 23, heat accumulation in area orchards was as follows:  

Sewell Orchard: 325 Degree Days - Custer Gavette: 332 Degree Days - Everson Copeland: 326 Degree Days - Nugents Corner 

This degree day information is based on the first reported CM flight or BIOFIX which occurred on May 12. Total degree days were reset to 200 on that date. Cumulative average trap catch in area orchards as of May 23 ranges from just over 3 moths/trap to as high as 8 moths/trap in older blocks with a history of this insect. Where cumulative trap catch averages 6 or more moths between 200 and 450 DD, an initial spray is best timed at 450DD. I expect this will be during the first week in June. Orchards with less CM pressure can delay this first generation spray to 560DD depending on history and current season trap catch. For assistance in management guidelines, refer to "Orchard Pest Management" published by the Goodfruit Grower or the Nooksack IPM barn chart which was passed out at the last breakfast meeting. This chart allows you to consolidate weather and trap catch records for quick reference. If you would like one of these charts, contact Geoff Menzies at 384-9135.  

White Apple Leafhopper  

This insect is an indirect pest which can reduce tree vigor by feeding, usually, on older leaves which results in reduced photosynthetic efficiency. There are no precise economic thresholds established but younger trees are more likely to be affected, particularly if leafhopppers are allowed to build to high levels for more than one season. As in most IPM programs, timing is important. Experience in local orchards has shown that 2 - 3 first generation leafhopper nymphs per leaf can become a menacing problem at harvest. We have also seen that low rates of Provado applied either in late May or at approximately 450DD provides excellent season-long control. Now is the time to scout for this insect. To evaluate leafhopper density, check 5 leaves per tree on 10 to 20 randomly chosen trees per block.  

For Information Contact:  

Geoff Menzies, Project Coordinator 
Phone: (360) 384-9135 
e-mail: gmenz@coopext.cahe.wsu.edu