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Thursday, October 1, 2009

A new field season

Strawberry plots from 2008-2009 biological control trials at Salisbury (Piedmont Research Station). These trials are being repeated in 2009-2010, with our first treatments being applied next week!

A few colleagues and grad students have been asking me lately "Is your field season winding down?", and the answer is, it's time for a whole new field season! August and September are typically my slowest months, unless there are tobacco trials that need yield assessment. There's still some tobacco out in the field, but most of the insect issues are routine this time of year. Blueberries are long gone and only leafhoppers are left to treat. Blackberry primocanes are still going strong but until we ramp up our virus vector studies, fall is quiet for Rubus. I don't have any current grape projects, but their harvest is also winding down.

So what new season is starting? Strawberries, of course! Three trials that I am collaborating on are in the ground and spider mite assessment will start next week. My own strawberry trials at Clayton, NC will be planted on Tuesday, October 6th.

What are we looking at in this trials? At Salisbury at Laurel Springs, I am piggy backing on 2 of Barclay Poling's row cover trials. We are trying to determine the impact of different row cover durations on overwintering twospotted spider mite populations. Barclay has shown a significant advantage to row covers under certain conditions, but I want to be sure that mite issues are not exacerbated under these row cover regimes. If they are, we'll then need to develop management strategies that take this into account.

We are conducting the 2nd year of winter biological control assessment for twospotted spider mite in one the high tunnels at Salisbury. At Clayton, we will be conducting threshold validation studies for twospotted spider mites and playing around with a few other row cover strategies.

Why so many mite trials?
All of these trials are focussed on twospotted spider mites for a reason; they are the key arthropod pest of strawberries in North Carolina. Their feeding activity can significantly impact plant health and yield. Spider mites can also be challenging to control--if miticides are used, good coverage is essential. If biological control is used, timing is important.

Why are you starting now?
Although it feels counterintuitive, twospotted spider mite damage results in the greatest yield reduction when it occurs early in the season, pre fruiting, when the plant is setting up the number of fruit it will produce the following spring. So, mite management following planting through the beginning of harvest is key.

Where will the information from these trials be available?
Here, for one. I will post regular updates on mite densities and any other interesting information that results from these trials. I will also present data from these trials in next summer's strawberry preplant meetings, and next spring's strawberry field day.

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