On the basis of the presented studies, it was established that seed dressing by coating protects effectively onion crops against onion fly (Hylemyia antiqua Meig.). In all seed dressing treatments, a significant decrease of number of damaged plants was found in comparison to the control. The highest efficacy in protection of onion against onion fly was shown in the case of insecticide Super Homai 70 DS. The effectiveness of this seed dressing reached 80.40% in the year 2001 and 85.44% in the year 2002.
The presented study deals with new capabilities of tree height estimation based on the remote sensing techniques. The main goal of this study is to find out the accuracy of tree height estimation based on LiDAR data and stereo−photogrammetric measurements. The area of investigation is located in the Western Sudetes Mountains (southern Poland). There were 75 trees chosen (Picea sp.) and measured using three different methods: traditional field measurements, stereo – photogrammetric observations and Airborne Laser Scanning (ALS). Tree heights estimated using LiDAR data and stereo−photogrammetric measurements were compared to heights acquired in the field. The mean tree height difference between LiDAR and field measurements was 0.60 m (RMSE=1.47 m), whereas the mean tree height difference between stereo−photogrammetric measurements and field equaled to –0.55 m (RMSE=1.04 m). The obtained results allow the conclusion to be drawn that Airborne Laser Scanning and stereo−photogrammetric observations are competitive with traditional methods of forest parameters measurements owing to the automation and accuracy of surveys. This study has confirmed that remote sensing techniques are effective and reliable methods of obtaining data for forest inventory.