Controlling thrips at an early stage is very important as we try to protect these young and rapidly developing plants from damage. Excessive amounts of damage to these first leaves or growing point can have a huge impact on how the plant develops later and ultimately performs. Preventive insecticidal seed treatments provide control up to 3 weeks after planting. However, this can vary with growing conditions and the weather.
Once the plant reaches the 3 to 4 true leaf stage, with a healthy growing point and true leaves, growth accelerates rapidly and the risk of thrips damage usually starts to decrease. However, the plants will need to reach pinhead square stage before they are truly past economic thrips damage.
During the plant’s early growth stages, growers should apply foliar insecticide at a threshold level of 1 thrips per true leaf. When scouting for thrips, there is truly no substitute for whole plant inspections from a representative sample from across the whole field. More information on thrips management can be found at: http://lubbock.tamu.edu/files/2017/05/ENTO-069_fn.pdf
Check out our video to know how to scout for thrips: https://www.youtube.com/watch?v=uD2dIDQmRb0