Thrips Flight and TSWV Risk Assessment Report – April 26, 2018

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This is the sixth thrips flight and TSWV risk assessment report. Read about why we are posting these reports and more in our first report here. Read more about tobacco thrips biology and TSWV transmission here.

Rain has delayed tobacco transplant in much of eastern NC, and growers are reminded to use the most recent information available to make management decisions. The predictions presented below will improve as we get closer to transplant dates and after transplant. As transplant is pushed back later, there is increased potential that fields will be set during a thrips flight, which can increase the risk of TSWV infection. The information presented here is intended to supplement, but not replace, farm specific predictions.

Note that some of the thrips flight dates are slightly different in the report below than in our first report. This is because we have switched to using ZIP codes for cities rather than selecting them from a map. This shifted the locations which we used weather data for slightly. These differences do not change overall recommendations, but they do underscore how important it is for growers to generate predictions for their own field locations.

Kenly is a relatively low TSWV risk site, situated within large acreage production areas in Johnston and Wilson Counties. As of today, TSWV infection risk in Kenly is lower than in a typical year. The third generation tobacco thrips flight (the generation that typically transmits the most TSWV) is not expected to occur during the next 14 days. At this time last year, we were 82% of the way to the third generation thrips flight, and this year, we are 59% of the way to the third generation thrips flight.This means that the population is maturing slower in 2018 than in 2017. Last year the third generation thrips flight occurred on May 10Growers near Kenly planning to transplant within the next 14 days likely do not need to take additional management precautions for TSWV at this time.

Beulaville is a higher TSWV risk site in Duplin County. As of today, TSWV infection risk in Beulaville is lower than in a typical year. The third generation tobacco thrips flight (the generation that typically transmits the most TSWV) is not expected to occur during the next 14 days. At this time last year, we were 86% of the way to the third generation thrips flight, and this year, we are 66% of the way to the third generation thrips flight. This means that the population is maturing slower in 2018 than in 2017. Last year the third generation thrips flight occurred on May 4Growers near Beulaville planning to transplant within the next 14 days likely do not need to take additional management precautions for TSWV at this time.

Kinston is a moderate TSWV risk site in Lenior County and also houses the NCDA & CS Cunningham Research Station where we conduct tobacco research. As of today, TSWV infection risk in Kinston is slightly lower than in a typical year. The third generation tobacco thrips flight (the generation that typically transmits the most TSWV) is not expected to occur during the next 14 days. At this time last year, we were 92% of the way to the third generation thrips flight, and this year, we are 72% of the way to the third generation thrips flight. This means that the population is maturing slower in 2018 than in 2017. Last year the third generation thrips flight occurred on April 30Growers near Kinston planning to transplant within the next 14 days likely do not need to take additional management precautions for TSWV at this time.

New Bern is a higher TSWV risk site. As of today, TSWV infection risk in New Bern is lower than in a typical year. The third generation tobacco thrips flight (the generation that typically transmits the most TSWV) is not expected to occur during the next 14 days. At this time last year, we were 85% of the way to the third generation thrips flight, and this year, we are 66% of the way to the third generation thrips flight. This means that the population is maturing slower in 2018 than in 2017. Last year the third generation thrips flight occurred on May 5Growers near New Bern planning to transplant within the next 14 days likely do not need to take additional management precautions for TSWV at this time.

Windsor is a higher TSWV risk site. As of today, TSWV infection risk in Windsor is slightly lower than in a typical year. The third generation tobacco thrips flight (the generation that typically transmits the most TSWV) is not expected to occur during the next 14 days. At this time last year, we were 69% of the way to the third generation thrips flight, and this year, we are 52% of the way to the third generation thrips flight.This means that the population is maturing slower in 2018 than in 2017. Last year the third generation thrips flight occurred on May 19Growers near Windsor planning to transplant within the next 14 days likely do not need to take additional management precautions for TSWV at this time.

Whiteville is a moderate TSWV risk site in Columbus County and also houses the NCDA & CS Border Belt Tobacco Research Station where we conduct tobacco research. As of today, TSWV infection risk in Whiteville is slightly lower than in a typical year. The third generation tobacco thrips flight (the generation that typically transmits the most TSWV) is not expected to occur during the next 14 days. At this time last year, we were 90% of the way to the third generation thrips flight, and this year, we are 69% of the way to the third generation thrips flight. This means that the population is maturing slower in 2018 than in 2017. Last year the third generation thrips flight occurred on May 2Growers near Whiteville planning to transplant within the next 14 days likely do not need to take additional management precautions for TSWV at this time, but they should check back before transplant!

Carthage is a relatively low TSWV risk site in Moore County. As of today, TSWV infection risk in Carthage is lower than in a typical year. The third generation tobacco thrips flight (the generation that typically transmits the most TSWV) is not expected to occur during the next 14 days. At this time last year, we were 81% of the way to the third generation thrips flight, and this year, we are 42% of the way to the third generation thrips flight. This means that the population is maturing slower in 2018 than in 2017. Last year the third generation thrips flight occurred on May 11Growers near Carthage planning to transplant within the next 14 days likely do not need to take additional management precautions for TSWV at this time.

Clinton is a higher TSWV risk site in Sampson County. As of today, TSWV infection risk in Clinton is less than in a typical year. The third generation tobacco thrips flight (the generation that typically transmits the most TSWV) is not expected to occur during the next 14 days. At this time last year, we were 88% of the way to the third generation thrips flight, and this year, we are 72% of the way to the third generation thrips flight. This means that the population is maturing slower in 2018 than in 2017. Last year the third generation thrips flight occurred on May 3Growers near Clinton planning to transplant within the next 14 days likely do not need to take additional management precautions for TSWV at this time.

In order to get the most accurate risk assessment, we recommend you enter your own farm data into the TSWV and Tobacco Thrips Risk Forecasting Tool. The following information is needed:

1. Field location (address, coordinates, nearest ZIP code, or selected from a map)

2. TSWV infection percentage in a typical year at this location

In addition, you can provide the following optional information which will improve recommendations:

3. Anticipated planting date

4. Greenhouse applications of imidacloprid and/or Actigard

More Information

Tobacco thripsTobacco Growers Information

Written By

Photo of Hannah Burrack, N.C. Cooperative ExtensionDr. Hannah BurrackAssoc. Professor and Extension Specialist (Berry, Tobacco and Specialty Crops) (919) 513-4344 hannah_burrack@ncsu.eduEntomology & Plant Pathology - NC State University
Posted on Apr 26, 2018
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