Bekæmpelse af tidligt forekommende skadedyr, trips

Conclusion

In 2023 in sugar beets, attacks of thrips (Thrips angusticeps) have been treated with Lamdex in a strip designed trial and a randomized trial. In the strip trial, treatment with 0.2 kg Lamdex per ha have been applied at the two-leaf stage of the plants with approx. 30 per cent of damage. Two weeks later, visual assessments show that the treatment has reduced the attack, however, at harvest, no additional yield has been measured in comparison to untreated.
In the randomized trial, 0.2 kg Lamdex per ha is applied at cotyledon and/or at two-leaf stage of the plants on plants with thrips damage of approx. 3 and 40 per cent. The treatments show a tendency to reduce the attack. At harvest, a yield increase of between 3 and 4 per cent is indicated with the treatments, but without obtained statistical difference to untreated. In the trial, also the non-approved insecticide Mavrik is tested using 0.2 l per ha, which shows similar results as with Lamdex. In average of five and three years of trials, attack of thrips are observed to be reduced by the treatments with one or two sprayings with either Lamdex or Mavrik. Additional yields of between 0 and 2 per cent are measured with the treatments without statistical difference to untreated.