Cotton Thrips Forecasting Tool Helps Preplant Decisions
North Carolina State University has developed a thrips forecasting tool to help cotton farmers make preplant management decisions. Thrips injury is a function of weather-driven seedling growth and thrips pressure. The tool uses planting date, temperature, precipitation and knowledge of when and how severe thrips pressure will be to predict time of risk.
It is known that something preplant for thrips is needed. It can be an insecticidal seed treatment or an insecticide in-furrow. The new tool helps in making decisions on whether one should you use a seed treatment and an in-furrow, or a foliar spray. It will help planters save time and money by making them use most intensive thrips management efforts on cotton that will be planted at a time that is most at risk for thrips.
“If you base a thrips spray off injury, it is usually too late to prevent damage to the crop. Immature thrips are a good sign that at-plant insecticides are running their course and a spray might be needed. Don’t forget that cotton is most sensitive to thrips damage when the 1st true leaf begins to appear between the cotyledons,” Southeast Farmpress said.
Although foliar sprays at later stages may occasionally benefit yields, targeting sprays when the first true leaf appears has been proven to be the most effective, it said.
This tool will give the best predictions within 10-14 days after the date it is used since it is based on weather forecasts. Therefore, it should be used two weeks before one plants. It should also be checked a few days before planting. Then, it should be used every week after planting to track damage potential until cotton is at the four leaf stage.
Since the tool is based on many years of data from across the Southeast US Cotton belt and has been validated several years, it is expected to accurately forecast thrips risk to cotton.