As the 2026 tobacco season approaches, we are resuming our updates on the risk of TSWV in North Carolina. Effective management of TSWV relies on decisions made both pre- and post-transplant. Because TSWV is transmitted by tobacco thrips, the timing of management practices, such as early planting, is most effective when aligned with periods of thrips movement.

To assist tobacco growers in anticipating these risks, we will provide regular reports/updates of predictions generated by the TSWV and Tobacco Thrips Risk Forecasting Tool for selected locations in eastern North Carolina, where moderate to severe TSW disease is often observed. These reports will highlight current model outputs and discuss how the information may inform pest management decisions. Because model predictions become more precise as the transplant window approaches, growers are encouraged to consult the most recent updates and use the forecasting tool more frequently as planting dates near.

This is the first report of the 2026 season. Winter conditions were generally consistent with historical temperature patterns for the region, with average temperatures within the typical range for eastern North Carolina winters. However, total precipitation during this period was slightly lower than the historical average.

Because winter temperature and rainfall can influence overwinter survival and early-season population development of tobacco thrips, these patterns are important for interpreting early TSWV risk forecasts, which may raise concerns about early thrips activity in the spring, reinforcing the importance of monitoring thrips movement and aligning management decisions with forecasted risk periods.

Based on the degree-day models for the 2026 season, the 3rd tobacco thrips flight, which is responsible for most TSWV transmission, is predicted to occur around May 17 in Kenly, May 12 in Kinston, May 11 in New Bern, and May 5 in Whiteville. Because young tobacco plants are most susceptible during the first several weeks after transplanting, early transplant dates (~three to four weeks before the onset of the 3rd thrips flight) allow plants to grow beyond their most susceptible stage before peak TSWV transmission occurs.

In areas of the state where the 3rd generation is predicted later in May (e.g., Kinston and Kenly), transplant dates in the second and third weeks of April may bring plants to a growth stage that carries less risk of TSW disease, and at the same time avoid most of the current predictions for the major thrips flights. Transplant windows in areas such as Kinston and Kenly, provided that weather forecasts indicate a low risk of damaging frost. Early April transplant windows in warm southern and coastal areas (e.g., Whiteville and New Bern) may help minimize overlap between young plants and 3rd and 4th generations of thrips, as long as there is a low risk of damaging frost (rare but possible in the first week of April). This balance between avoiding freeze injury and minimizing overlap between early plant susceptibility and peak thrips movement is critical for reducing TSWV risk in North Carolina tobacco production systems.

This and future updates are created based on reports generated with the Tobacco Thrips Flight and TSWV Intensity Predictor. Predictor settings include no insecticide treatment, desired planting date (April 8 used as early planting date, April 15 as standard, April 22 and beyond as later planting dates), and the average historical TSWV incidence for each location, as listed below:

• Kenly is a relatively low TSWV risk site (typically less than 8%), situated within large acreage production areas in Johnston and Wilson Counties.
• Kinston is a moderate TSWV risk site (typically around 8%) in Lenoir County and also houses the NCDA&CS Cunningham Research Station, where extensive tobacco research is conducted.
• New Bern is a higher TSWV risk site (typically above 10%) in Craven County.
• Whiteville is a moderate to high TSWV risk site (around or above 10%) in Columbus County and also houses the NCDA & CS Border Belt Tobacco Research Station , where tobacco research is conducted.